Showing papers in "Ear and Hearing in 2013"

Factors affecting open-set word recognition in adults with cochlear implants.

Abstract: Objective A great deal of variability exists in the speech-recognition abilities of postlingually deaf adult cochlear implant (CI) recipients. A number of previous studies have shown that duration of deafness is a primary factor affecting CI outcomes; however, there is little agreement regarding other factors that may affect performance. The objective of the present study was to determine the source of variability in CI outcomes by examining three main factors, biographic/audiologic information, electrode position within the cochlea, and cognitive abilities in a group of newly implanted CI recipients. Design Participants were 114 postlingually deaf adults with either the Cochlear or Advanced Bionics CI systems. Biographic/audiologic information, aided sentence-recognition scores, a high resolution temporal bone CT scan and cognitive measures were obtained before implantation. Monosyllabic word recognition scores were obtained during numerous test intervals from 2 weeks to 2 years after initial activation of the CI. Electrode position within the cochlea was determined by three-dimensional reconstruction of pre- and postimplant CT scans. Participants' word scores over 2 years were fit with a logistic curve to predict word score as a function of time and to highlight 4-word recognition metrics (CNC initial score, CNC final score, rise time to 90% of CNC final score, and CNC difference score). Results Participants were divided into six outcome groups based on the percentile ranking of their CNC final score, that is, participants in the bottom 10% were in group 1; those in the top 10% were in group 6. Across outcome groups, significant relationships from low to high performance were identified. Biographic/audiologic factors of age at implantation, duration of hearing loss, duration of hearing aid use, and duration of severe-to-profound hearing loss were significantly and inversely related to performance as were frequency modulated tone, sound-field threshold levels obtained with the CI. That is, the higher-performing outcome groups were younger in age at the time of implantation, had shorter duration of severe-to-profound hearing loss, and had lower CI sound-field threshold levels. Significant inverse relationships across outcome groups were also observed for electrode position, specifically the percentage of electrodes in scala vestibuli as opposed to scala tympani and depth of insertion of the electrode array. In addition, positioning of electrode arrays closer to the modiolar wall was positively correlated with outcome. Cognitive ability was significantly and positively related to outcome; however, age at implantation and cognition were highly correlated. After controlling for age, cognition was no longer a factor affecting outcomes. Conclusion There are a number of factors that limit CI outcomes. They can act singularly or collectively to restrict an individual's performance and to varying degrees. The highest performing CI recipients are those with the least number of limiting factors. Knowledge of when and how these factors affect performance can favorably influence counseling, device fitting, and rehabilitation for individual patients and can contribute to improved device design and application.

The effects of hearing aid use on listening effort and mental fatigue associated with sustained speech processing demands.

Abstract: Objectives:To maintain optimal understanding, persons with sensorineural hearing loss (SNHL) often report a need for increased attention, concentration, and “listening effort” compared with persons without hearing loss. It is generally assumed that this increased effort is related to subjective repo

Outcomes of early- and late-identified children at 3 years of age: findings from a prospective population-based study.

Abstract: Objective:To address the question of whether, on a population level, early detection and amplification improve outcomes of children with hearing impairment.Design:All families of children who were born between 2002 and 2007, and who presented for hearing services below 3 years of age at Australian H

Cochlear implantation with hearing preservation yields significant benefit for speech recognition in complex listening environments

Abstract: Objective The aim of this study was to assess the benefit of having preserved acoustic hearing in the implanted ear for speech recognition in complex listening environments. Design The present study included a within-subjects, repeated-measures design including 21 English-speaking and 17 Polish-speaking cochlear implant (CI) recipients with preserved acoustic hearing in the implanted ear. The patients were implanted with electrodes that varied in insertion depth from 10 to 31 mm. Mean preoperative low-frequency thresholds (average of 125, 250, and 500 Hz) in the implanted ear were 39.3 and 23.4 dB HL for the English- and Polish-speaking participants, respectively. In one condition, speech perception was assessed in an eight-loudspeaker environment in which the speech signals were presented from one loudspeaker and restaurant noise was presented from all loudspeakers. In another condition, the signals were presented in a simulation of a reverberant environment with a reverberation time of 0.6 sec. The response measures included speech reception thresholds (SRTs) and percent correct sentence understanding for two test conditions: CI plus low-frequency hearing in the contralateral ear (bimodal condition) and CI plus low-frequency hearing in both ears (best-aided condition). A subset of six English-speaking listeners were also assessed on measures of interaural time difference thresholds for a 250-Hz signal. Results Small, but significant, improvements in performance (1.7-2.1 dB and 6-10 percentage points) were found for the best-aided condition versus the bimodal condition. Postoperative thresholds in the implanted ear were correlated with the degree of electric and acoustic stimulation (EAS) benefit for speech recognition in diffuse noise. There was no reliable relationship among measures of audiometric threshold in the implanted ear nor elevation in threshold after surgery and improvement in speech understanding in reverberation. There was a significant correlation between interaural time difference threshold at 250 Hz and EAS-related benefit for the adaptive speech reception threshold. Conclusions The findings of this study suggest that (1) preserved low-frequency hearing improves speech understanding for CI recipients, (2) testing in complex listening environments, in which binaural timing cues differ for signal and noise, may best demonstrate the value of having two ears with low-frequency acoustic hearing, and (3) preservation of binaural timing cues, although poorer than observed for individuals with normal hearing, is possible after unilateral cochlear implantation with hearing preservation and is associated with EAS benefit. The results of this study demonstrate significant communicative benefit for hearing preservation in the implanted ear and provide support for the expansion of CI criteria to include individuals with low-frequency thresholds in even the normal to near-normal range.

Age-Related Changes in Listening Effort for Various Types of Masker Noises

Abstract: Objective The purpose of the present study was to evaluate the relationship between cognitive function, listening effort, and speech recognition for a group of younger and older adults with normal hearing and a group of older adults with hearing impairment in various types of background maskers. The authors hypothesize that, as the masker condition becomes more difficult listening effort will increase, but the increase will be greater for older participants than for younger participants. Design A dual-task paradigm was used to objectively evaluate listening effort. The primary task required participants to repeat sentences presented in three different background-masker conditions: (1) two-talker (TT), (2) six-talker, and (3) speech-shaped noise (SSN). The secondary task was a Digital Visual Pursuit Rotor Tracking test, for which participants were instructed to use a computer mouse to track a moving target around an ellipse that was displayed on a computer screen. Each of the two tasks was separately and concurrently presented at a fixed overall speech-recognition performance level of 76% correct. In addition, participants subjectively rated how easy it was to listen to the sentences in each masker condition on a scale from 0 (i.e., very difficult) to 100 (i.e., very easy). Last, participants completed a battery of cognitive tests that measured working memory (Reading Span Test), processing speed (Digit Symbol Substitution Test), and selective attention (Stroop Test) ability. Results Results revealed that participants' working memory and processing speed abilities were significantly related to their speech-recognition performance in noise in all three background-masker conditions. Participants rated the TT condition to be the most difficult listening condition and the SSN condition to be the easiest listening condition. Both groups of older participants expended significantly more listening effort than younger participants did in the SSN and TT masker conditions. For each group of participants, there were no significant differences in listening effort measured across the masker conditions, with the exception of the younger participants, who expended more effort listening in the six-talker masker condition compared with the SSN condition. Participants' listening effort expended on the TT and SSN masker conditions was significantly correlated with their working memory and processing speed performance. Conclusions Findings from the present study indicate that older adults require more cognitive resources than younger adults to understand speech in background noise.

The effects of hearing impairment and aging on spatial processing.

Abstract: Objectives Difficulty in understanding speech in background noise is frequently reported by hearing-impaired people despite well-fitted amplification. Understanding speech in the presence of background noise involves segregating the various auditory stimuli into distinct streams using cues such as pitch characteristics, spatial location of speakers, and contextual information. One possible cause of listening difficulties in noise is reduced spatial-processing ability. Previous attempts to investigate spatial processing in hearing-impaired people have often been confounded by inadequate stimulus audibility. The present research aimed to investigate the effects of hearing impairment and aging on spatial-processing ability. The effect of cognitive ability on spatial processing was also explored. In addition, the relationship between spatial-processing ability and self-report measures of listening difficulty was examined to investigate how much effect spatial-processing ability has in real-world situations. Design Eighty participants aged between 7 and 89 years took part in the study. Participants' hearing thresholds ranged from within normal limits to a moderately severe sensorineural hearing loss. All participants had English as their first language and no reported learning disabilities. The study sample included both hearing aid users and non-hearing aid users. Spatial-processing ability was assessed with a modified version of the Listening in Spatialized Noise-Sentences test (LiSN-S). The LiSN-S was modified to incorporate a prescribed gain amplifier that amplified the target and distracting stimulus according to the National Acoustic Laboratories-Revised Profound (NAL-RP) prescription. In addition, participants aged 18 years and above completed the Neurobehavioral Cognitive Status examination and the Speech, Spatial and Qualities questionnaire. Participants aged under 18 years completed the Listening Inventory for Education questionnaire. Results Spatial-processing ability, as measured by the spatial advantage measure of the LiSN-S, was negatively affected by hearing impairment. Aging was not significantly correlated with spatial-processing ability. No significant relationship was found between cognitive ability and spatial processing. Self-reported listening difficulty in children, as measured with the Listening Inventory for Education, and spatial-processing ability were not correlated. Self-reported listening difficulty in adults, as measured by the Speech, Spatial and Qualities questionnaire, was significantly correlated with spatial-processing ability. Conclusions All hearing-impaired people will have a spatial processing deficit of some degree. This should be given due consideration when counseling patients in regard to realistic expectations of how they will perform in background noise. Further research is required into potential remediation for spatial-processing deficits and the cause of these deficits.

Working memory, age, and hearing loss: susceptibility to hearing aid distortion.

Abstract: Objectives Hearing aids use complex processing intended to improve speech recognition. Although many listeners benefit from such processing, it can also introduce distortion that offsets or cancels intended benefits for some individuals. The purpose of the present study was to determine the effects of cognitive ability (working memory) on individual listeners' responses to distortion caused by frequency compression applied to noisy speech. Design The present study analyzed a large data set of intelligibility scores for frequency-compressed speech presented in quiet and at a range of signal-to-babble ratios. The intelligibility data set was based on scores from 26 adults with hearing loss with ages ranging from 62 to 92 years. The listeners were grouped based on working memory ability. The amount of signal modification (distortion) caused by frequency compression and noise was measured using a sound quality metric. Analysis of variance and hierarchical linear modeling were used to identify meaningful differences between subject groups as a function of signal distortion caused by frequency compression and noise. Results Working memory was a significant factor in listeners' intelligibility of sentences presented in babble noise and processed with frequency compression based on sinusoidal modeling. At maximum signal modification (caused by both frequency compression and babble noise), the factor of working memory (when controlling for age and hearing loss) accounted for 29.3% of the variance in intelligibility scores. Combining working memory, age, and hearing loss accounted for a total of 47.5% of the variability in intelligibility scores. Furthermore, as the total amount of signal distortion increased, listeners with higher working memory performed better on the intelligibility task than listeners with lower working memory did. Conclusions Working memory is a significant factor in listeners' responses to total signal distortion caused by cumulative effects of babble noise and frequency compression implemented with sinusoidal modeling. These results, together with other studies focused on wide-dynamic range compression, suggest that older listeners with hearing loss and poor working memory are more susceptible to distortions caused by at least some types of hearing aid signal-processing algorithms and by noise, and that this increased susceptibility should be considered in the hearing aid fitting process.

Tinnitus: a cost study.

Abstract: Objectives: The aim of this study was to examine the costs of tinnitus in The Netherlands from a health care and a societal perspective. Furthermore, the impact of disease characteristics and demographic characteristics on these costs were examined. Methods: A bottom-up cost of illness study was performed, using the baseline data on a cost questionnaire of a randomized controlled trial investigating the (cost) effectiveness of an integral multidisciplinary treatment for tinnitus versus care as usual. Mean yearly costs were multiplied by the prevalence figure of tinnitus for the adult general population to estimate the total cost of illness of tinnitus to society. Because cost data usually are not normally distributed, a nonparametric bootstrap resampling procedure with 1000 simulations was performed to determine statistical uncertainty of the cost estimates per category. Several questionnaires measuring disease and demographic characteristics were administered. The impact of disease characteristics and demographics on costs was investigated using a multivariate regression analysis. Results: Total mean societal cost of illness was €6.8 billion (95% confidence interval: €3.9 billion–€10.8 billion). The larger part of total cost of illness was not related to health care. Total mean health care costs were €1.9 billion (95% confidence interval: €1.4 billion–€2.5 billion). Significant predictors of both health care costs and societal costs were tinnitus severity, age, shorter duration of tinnitus, and more severe depression. Conclusion: The economical burden of tinnitus to society is substantial, and severity of tinnitus is an important predictor of the costs made by patients. (Ear & Hearing 2013;00;0–0)

How hearing aids, background noise, and visual cues influence objective listening effort.

Abstract: Objectives The purpose of this article was to evaluate factors that influence the listening effort experienced when processing speech for people with hearing loss. Specifically, the change in listening effort resulting from introducing hearing aids, visual cues, and background noise was evaluated. An additional exploratory aim was to investigate the possible relationships between the magnitude of listening effort change and individual listeners' working memory capacity, verbal processing speed, or lipreading skill. Design Twenty-seven participants with bilateral sensorineural hearing loss were fitted with linear behind-the-ear hearing aids and tested using a dual-task paradigm designed to evaluate listening effort. The primary task was monosyllable word recognition and the secondary task was a visual reaction time task. The test conditions varied by hearing aids (unaided, aided), visual cues (auditory-only, auditory-visual), and background noise (present, absent). For all participants, the signal to noise ratio was set individually so that speech recognition performance in noise was approximately 60% in both the auditory-only and auditory-visual conditions. In addition to measures of listening effort, working memory capacity, verbal processing speed, and lipreading ability were measured using the Automated Operational Span Task, a Lexical Decision Task, and the Revised Shortened Utley Lipreading Test, respectively. Results In general, the effects measured using the objective measure of listening effort were small (~10 msec). Results indicated that background noise increased listening effort, and hearing aids reduced listening effort, while visual cues did not influence listening effort. With regard to the individual variables, verbal processing speed was negatively correlated with hearing aid benefit for listening effort; faster processors were less likely to derive benefit. Working memory capacity, verbal processing speed, and lipreading ability were related to benefit from visual cues. No variables were related to changes in listening effort resulting from the addition of background noise. Conclusions The results of this study suggest that, on the average, hearing aids can reduce objectively measured listening effort. Furthermore, people who are slow verbal processors are more likely to derive hearing aid benefit for listening effort, perhaps because hearing aids improve the auditory input. Although background noise increased objective listening effort, no listener characteristic predicted susceptibility to noise. With regard to visual cues, while there was no effect on average of providing visual cues, there were some listener characteristics that were related to changes in listening effort with vision. Although these relationships are exploratory, they do suggest that these inherent listener characteristics like working memory capacity, verbal processing speed, and lipreading ability may influence susceptibility to changes in listening effort and thus warrant further study.

Effects of age on the tuning of the cVEMP and oVEMP.

Abstract: Objectives The purpose of the present investigation was to define for young, middle-aged, and older adults the optimal frequency (cies) to record both the cervical vestibular-evoked myogenic potential (cVEMP) and the ocular vestibular-evoked myogenic potential (oVEMP). Further, this study aimed to describe age-related changes in the tuning of these two vestibular-evoked myogenic potentials. Design This was a prospective study. Participants were 39 healthy adults (mean age 46.3 ± 15.7 years; range = 22 to 78 years; 15 men) equally divided into 3 age groups of 13 participants each: young adult (18 to 39 years), middle age (40 to 59 years), and old adult (≥60 years). cVEMPs and oVEMPs were recorded using air-conduction tone bursts at stimulus frequencies of 125, 250, 500, 750, 1000, 1500, and 2000 Hz presented at 127 dB pSPL. Results There was a significant main effect of age group and frequency on the amplitude of both the cVEMP and the oVEMP. Amplitudes were largest for the Young adult group for the cVEMP and for the young adult and Middle age group for the oVEMP. The largest average peak-to-peak amplitude occurred in response to a 750 Hz tone burst for both responses. No significant differences in mean amplitude of the cVEMP or oVEMP were observed for 500, 750, or 1000 Hz stimuli. There was a significant interaction of age group and frequency for the cVEMP, suggesting a loss of tuning for the old adult group. Compared with the young adult group, the tuning of the cVEMP and oVEMP for the older adjults appeared to shift to a higher frequency. Conclusion There is no sharp tuning in the saccule and utricle. Instead, there is a range of best frequencies that may be used to evoke the cVEMP and oVEMP responses. The results of the present investigation also demonstrate that the optimal stimulus frequency to elicit a VEMP may change with age. Accordingly, 500 Hz may not be the ideal frequency to elicit VEMPs for all age groups. For this reason, in cases where the VEMP response is absent at 500 Hz it is recommended that attempts be made to record the VEMP for tone-burst frequencies of 750 or 1000 Hz.

Gender and chronic tinnitus: differences in tinnitus-related distress depend on age and duration of tinnitus.

Abstract: Objective:Conflicting data about the role of gender in tinnitus distress exist in the literature. In addition, little is known about gender differences regarding age and duration of tinnitus. Tinnitus was shown to be related to stress and impairment of coping, sense of coherence, and personal resour

Validity of Automated Threshold Audiometry: A Systematic Review and Meta-Analysis.

Abstract: Objectives A systematic literature review and meta-analysis on the validity (test-retest reliability and accuracy) of automated threshold audiometry compared with the gold standard of manual threshold audiometry was conducted. Design A systematic literature review was completed in peer-reviewed databases on automated compared with manual threshold audiometry. Subsequently a meta-analysis was conducted on the validity of automated audiometry. Methods A multifaceted approach, covering several databases and using different search strategies was used to ensure comprehensive coverage and to cross-check search findings. Databases included: MEDLINE, Scopus, and PubMed; a secondary search strategy was the review of references from identified reports. Reports including within-subject comparisons of manual and automated threshold audiometry were selected according to inclusion/exclusion criteria before data were extracted. For the meta-analysis weighted mean differences (and standard deviations) on test-retest reliability for automated compared with manual audiometry were determined to assess the validity of automated threshold audiometry. Results In total, 29 reports on automated audiometry (method of limits and the method of adjustment techniques) met the inclusion criteria and were included in this review. Most reports included data on adult populations using air conduction testing with limited data on children, bone conduction testing and the effects of hearing status on automated audiometry. Meta-analysis test-retest reliability for automated audiometry was within typical test-retest variability for manual audiometry. Accuracy results on the meta-analysis indicated overall average differences between manual and automated air conduction audiometry (0.4 dB, 6.1 SD) to be comparable with test-retest differences for manual (1.3 dB, 6.1 SD) and automated (0.3 dB, 6.9 SD) audiometry. No significant differences (p > 0.01; summarized data analysis of variance) were seen in any of the comparisons between test-retest reliability of manual and automated audiometry compared with differences between manual and automated audiometry. Conclusion Automated audiometry provides an accurate measure of hearing threshold, but validation data are still limited for (1) automated bone conduction audiometry; (2) automated audiometry in children and difficult-to-test populations and; (3) different types and degrees of hearing loss.

Verbal short-term memory development and spoken language outcomes in deaf children with cochlear implants.

Abstract: Objectives Cochlear implants (CIs) help many deaf children achieve near normal speech and language (S/L) milestones. Nevertheless, high levels of unexplained variability in S/L outcomes are limiting factors in improving the effectiveness of CIs in deaf children. The objective of this study was to longitudinally assess the role of verbal short-term memory (STM) and working memory (WM) capacity as a progress-limiting source of variability in S/L outcomes following CI in children.

Characteristics of hearing aid fittings in infants and young children.

Abstract: Objectives Hearing aids (HAs) provide the basis for improving audibility and minimizing developmental delays in children with mild to severe hearing loss. Multiple guidelines exist to recommend methods for optimizing amplification in children, but few previous studies have reported HA fitting outcomes for a large group of children. The present study sought to evaluate the proximity of the fitting to prescriptive targets and aided audibility of speech, as well as survey data from pediatric audiologists who provided HAs for the children in the present study. Deviations from prescriptive target were predicted to have a negative impact on aided audibility. In addition, children who were fitted using verification with probe microphone measurements were expected to have smaller deviations from prescriptive targets and greater audibility than cohorts fitted without these measures. Design HA fitting data from 195 children with mild to severe hearing losses were analyzed as part of a multicenter study evaluating outcomes in children with hearing loss. Proximity of fitting to prescriptive targets was quantified by calculating the average root-mean-square (RMS) error of the fitting compared with Desired Sensation Level prescriptive targets for 500, 1000, 2000, and 4000 Hz. Aided audibility was quantified using the Speech Intelligibility Index. Survey data from the pediatric audiologists who fit amplification for children in the present study were collected to evaluate trends in fitting practices and relate those patterns to proximity of the fitting to prescriptive targets and aided audibility. Results More than half (55%) of the children in the study had at least 1 ear that deviated from prescriptive targets by more than 5 dB RMS on average. Deviation from prescriptive target was not predicted by pure-tone average, assessment method, or reliability of assessment. Study location was a significant predictor of proximity to prescriptive target with locations that recruited participants who were fit at multiple clinical locations (University of Iowa and Boys Town National Research Hospital) having larger deviations from target than the location where the participants were recruited primarily from a single, large pediatric audiology clinic (University of North Carolina). Fittings based on average real-ear to coupler differences resulted in larger deviations from prescriptive targets than fittings based on individually measured real-ear to coupler differences. Approximately 26% of the children in the study has aided audibility less than 0.65 on the Speech Intelligibility Index (SII). Aided audibility was significantly predicted by the proximity to prescriptive targets and pure-tone average, but not age in months. Conclusions Children in the study had a wide range of fitting outcomes in terms of proximity to prescriptive targets (RMS error) and aided speech audibility (SII). Even when recommended HA verification strategies were reported, fittings often exceeded the criteria for both proximity to the prescriptive target and aided audibility. The implications for optimizing amplification for children are also discussed.

Hearing in Time: evoked Potential Studies of Temporal Processing

Abstract: This article reviews the temporal aspects of human hearing as measured using the auditory evoked potentials. Interaural timing cues are essential to the detection and localization of sound sources. The temporal envelope of a sound--how it changes in amplitude over time--is crucially important for speech perception. Time is taken to integrate, identify, and dissolve auditory streams. These temporal aspects of human hearing can be examined using the auditory evoked potentials, which measure the millisecond-by-millisecond activity of populations of neurons as they form an auditory percept. Important measurements are the time taken to localize sounds on the basis of their interaural time differences as measured by the cortical N1 wave, the contribution of the vocal cord frequency and phonemic frequency to the perception of speech sounds as indicated by the envelope-following responses, the temporal integration of sound as assessed using the steady state responses, and the duration of auditory memory as shown in the refractory periods of the slow auditory evoked potentials. Disorders of temporal processing are a characteristic feature of auditory neuropathy, a significant component of the hearing problems that occur in the elderly, and a possible etiological factor in developmental dyslexia and central auditory processing disorders. Auditory evoked potentials may help in the diagnosis and monitoring of these disorders.

Speech perception with combined electric-acoustic stimulation and bilateral cochlear implants in a multisource noise field.

Abstract: OBJECTIVE The aim of the study was to measure and compare speech perception in users of electric-acoustic stimulation (EAS) supported by a hearing aid in the unimplanted ear and in bilateral cochlear implant (CI) users under different noise and sound field conditions. Gap listening was assessed by comparing performance in unmodulated and modulated Comite Consultatif International Telephonique et Telegraphique (CCITT) noise conditions, and binaural interaction was investigated by comparing single source and multisource sound fields. METHODS Speech perception in noise was measured using a closed-set sentence test (Oldenburg Sentence Test, OLSA) in a multisource noise field (MSNF) consisting of a four-loudspeaker array with independent noise sources and a single source in frontal position (S0N0). Speech simulating noise (Fastl-noise), CCITT-noise (continuous), and OLSA-noise (pseudo continuous) served as noise sources with different temporal patterns. Speech tests were performed in two groups of subjects who were using either EAS (n = 12) or bilateral CIs (n = 10). All subjects in the EAS group were fitted with a high-power hearing aid in the opposite ear (bimodal EAS). The average group score on monosyllable in quiet was 68.8% (EAS) and 80.5% (bilateral CI). A group of 22 listeners with normal hearing served as controls to compare and evaluate potential gap listening effects in implanted patients. RESULTS Average speech reception thresholds in the EAS group were significantly lower than those for the bilateral CI group in all test conditions (CCITT 6.1 dB, p = 0.001; Fastl-noise 5.4 dB, p < 0.01; Oldenburg-(OL)-noise 1.6 dB, p < 0.05). Bilateral CI and EAS user groups showed a significant improvement of 4.3 dB (p = 0.004) and 5.4 dB (p = 0.002) between S0N0 and MSNF sound field conditions respectively, which signifies advantages caused by bilateral interaction in both groups. Performance in the control group showed a significant gap listening effect with a difference of 6.5 dB between modulated and unmodulated noise in S0N0, and a difference of 3.0 dB in MSNF. The ability to "glimpse" into short temporal masker gaps was absent in both groups of implanted subjects. CONCLUSIONS Combined EAS in one ear supported by a hearing aid on the contralateral ear provided significantly improved speech perception compared with bilateral cochlear implantation. Although the scores for monosyllable words in quiet were higher in the bilateral CI group, the EAS group performed better in different noise and sound field conditions. Furthermore, the results indicated that binaural interaction between EAS in one ear and residual acoustic hearing in the opposite ear enhances speech perception in complex noise situations. Both bilateral CI and bimodal EAS users did not benefit from short temporal masker gaps, therefore the better performance of the EAS group in modulated noise conditions could be explained by the improved transmission of fundamental frequency cues in the lower-frequency region of acoustic hearing, which might foster the grouping of auditory objects.

Stages of change in adults with acquired hearing impairment seeking help for the first time: application of the transtheoretical model in audiologic rehabilitation.

Abstract: OBJECTIVES:This study investigated the application of the transtheoretical (stages-of-change) model in audiologic rehabilitation. More specifically, it described the University of Rhode Island Chan ...

Relationship between auditory function of nonimplanted ears and bimodal benefit.

Abstract: Objectives—Patients with a cochlear implant (CI) in one ear and a hearing aid in the other ear commonly achieve the highest speech understanding scores when they have access to both electrically and acoustically stimulated information (EAS). At issue in this study was whether a measure of auditory function in the hearing-aided ear would predict the benefit to speech understanding when the information from the aided ear was added to the information from the CI. Design—The subjects were 22 bimodal listeners with a CI in one ear and low-frequency acoustic hearing in the non-implanted ear. The subjects were divided into two groups -- one with mild to moderate low-frequency loss and one with severe to profound loss. Measures of auditory function included (i) audiometric thresholds at ≤ 750 Hz, (ii) speech understanding scores (words in quiet and sentences in noise), and (iii) spectral modulation detection (SMD) thresholds. In the SMD task, one stimulus was a flat spectrum noise and the other was a noise with sinusoidal modulations at 1.0 peak/octave. Results—Significant correlations were found among all three measures of auditory function and the benefit to speech understanding when the acoustic and electric stimulation were combined. Benefit was significantly correlated with audiometric thresholds (r = −0.814), acoustic speech understanding (r = 0.635), and SMD thresholds (r = −0.895) in the hearing-aided ear. However, only the SMD threshold was significantly correlated with benefit within the group with mildmoderate loss (r = −0.828) and within the group with severe-profound loss (r = −0.896). Conclusions—The SMD threshold at 1 cycle/octave has the potential to provide clinicians with information relevant to the question of whether an ear with low-frequency hearing is likely to add to the intelligibility of speech provided by a CI.

Perceptual effects of noise reduction with respect to personal preference, speech intelligibility, and listening effort

Abstract: Objectives Most modern hearing aids use noise reduction to increase listening comfort in noisy environments. However, it is unclear whether perceptual effects (e.g., intelligibility, listening effort, and preference) of noise reduction differ among hearing aids and among listeners. The authors compared perceptual scores across different hearing aid noise-reduction systems to determine (1) whether noise-reduction systems differ perceptually and (2) which factors underlie the overall preference of individual listeners. Design The authors recorded hearing aid noise-reduction outputs and used these signals in a laboratory experiment. The recording method allowed the evaluation of noise reduction in an isolated form, without the dominant effects of hearing aid frequency response and interactions with dynamic-range compression. Ten normal-hearing subjects listened to speech in babble noise processed by noise reduction from four different hearing aids. The subjects performed (1) speech-intelligibility tests, (2) listening-effort ratings, and (3) paired-comparison ratings with respect to noise annoyance, speech naturalness, and overall preference. Results Noise-reduction systems from different hearing aids differed in the degree to which they influenced the noise annoyance and speech naturalness perceived by the normal-hearing listeners. Small differences in intelligibility and effort scores were found among different noise-reduction systems but not between having noise reduction on and off. Subjects differed in whether their overall preference was more strongly related to noise annoyance or to speech naturalness. Conclusions The authors conclude that noise annoyance and speech naturalness are determining factors for the overall preference of normal-hearing listeners for a specific noise-reduction condition, and found individual differences in the preferred weighting of these factors even in a homogeneous group of normal-hearing listeners. Subsequent experiments should include hearing-impaired subjects to determine whether these conclusions also hold for a more heterogeneous group of listeners. If these results can be extrapolated to hearing-impaired listeners, the fitting and fine-tuning of noise reduction in hearing aids needs considerable revision.

A new auditory threshold estimation technique for low frequencies: proof of concept.

Abstract: Objectives Presently available non-behavioral methods to estimate auditory thresholds perform less well at frequencies below 1 kHz than at 1 kHz and above. For many uses, such as providing accurate infant hearing aid amplification for low-frequency vowels, we need an accurate non-behavioral method to estimate low-frequency thresholds. Here we develop a novel technique to estimate low-frequency cochlear thresholds based on the use of a previously-reported waveform. We determine how well the method works by comparing the resulting thresholds to thresholds from onset-response compound action potentials (CAPs) and single auditory-nerve (AN) fibers in cats. A long-term goal is to translate this technique for use in humans.

Psychophysics, fitting, and signal processing for combined hearing aid and cochlear implant stimulation.

Abstract: The addition of acoustic stimulation to electric stimulation via a cochlear implant has been shown to be advantageous for speech perception in noise, sound quality, music perception, and sound source localization. However, the signal processing and fitting procedures of current cochlear implants and hearing aids were developed independently, precluding several potential advantages of bimodal stimulation, such as improved sound source localization and binaural unmasking of speech in noise. While there is a large and increasing population of implantees who use a hearing aid, there are currently no generally accepted fitting methods for this configuration. It is not practical to fit current commercial devices to achieve optimal binaural loudness balance or optimal binaural cue transmission for arbitrary signals and levels. There are several promising experimental signal processing systems specifically designed for bimodal stimulation. In this article, basic psychophysical studies with electric acoustic stimulation are reviewed, along with the current state of the art in fitting, and experimental signal processing techniques for electric acoustic stimulation.

Estimating young Australian adults' risk of hearing damage from selected leisure activities.

Abstract: Objective Several previous studies have attempted to estimate the risk of noise-induced hearing loss from loud leisure noise. Some of these studies may have overestimated the risk because they used noise estimates taken from the higher end of reported levels. The aim of the present study was to provide a realistic estimate of the number of young Australian adults who may be at risk of hearing damage and eventual hearing loss from leisure-noise exposure. Design Average noise levels at five high-noise leisure activities, (1) nightclubs; (2) pubs, bars, and registered clubs; (3) fitness classes; (4) live sporting events; (5) concerts and live music venues, were calculated using 108 measurements taken from a large database of leisure noise measurements. In addition, an online survey was administered to a convenience sample of 1000 young adults aged 18 to 35 years, who reported the time spent at these leisure activities and the frequency with which they undertook the activities. They also answered questions about tinnitus and their perceived risk of hearing damage. Although the survey data cannot be considered representative of the population of young Australian adults, it was weighted to this population in respect of age, gender, education, and location. The survey data and the average noise levels were used to estimate each individual's annual noise exposure, and in turn, estimate those at risk of hearing damage from leisure-noise exposure. Results For the majority of participants (n = 868), the accumulated leisure noise level was within the acceptable workplace limit. However, 132 participants or 14.1% (population weighted) were exposed to an annual noise dose greater than the acceptable workplace noise limit. By far, the main source of high-risk leisure noise was from nightclubs. Those with more leisure-noise exposure experienced more tinnitus and perceived themselves to be more at risk than those with lower noise exposures. Conclusions It is recommended that nightclub operators reduce noise levels, display warnings, and provide earplugs for patrons and employees. Health promoters should focus their attention on those young adults who are most at risk and provide them with targeted practical advice about reducing their leisure-noise exposure and avoiding hearing loss.

Effect of hearing aid bandwidth on speech recognition performance of listeners using a cochlear implant and contralateral hearing aid (bimodal hearing).

Abstract: Objectives The purpose of this study was to determine how the bandwidth of the hearing aid (HA) fitting affects bimodal speech recognition of listeners with a cochlear implant (CI) in one ear and severe-to-profound hearing loss in the unimplanted ear (but with residual hearing sufficient for wideband amplification using National Acoustic Laboratories Revised, Profound [NAL-RP] prescriptive guidelines; unaided thresholds no poorer than 95 dB HL through 2000 Hz). Design Recognition of sentence material in quiet and in noise was measured with the CI alone and with CI plus HA as the amplification provided by the HA in the high and mid-frequency regions was systematically reduced from the wideband condition (NAL-RP prescription). Modified bandwidths included upper frequency cutoffs of 2000, 1000, or 500 Hz. Results On average, significant bimodal benefit was obtained when the HA provided amplification at all frequencies with aidable residual hearing. Limiting the HA bandwidth to only low-frequency amplification (below 1000 Hz) did not yield significant improvements in performance over listening with the CI alone. Conclusions These data suggest the importance of providing amplification across as wide a frequency region as permitted by audiometric thresholds in the HA used by bimodal users.

Age-dependent cost-utility of pediatric cochlear implantation

Abstract: Objectives: Cochlear implantation (CI) has become the mainstay of treatment for children with severe-to-profound sensorineural hearing loss (SNHL). Yet, despite mounting evidence of the clinical benefits of early implantation, little data are available on the long-term societal benefits and comparative effectiveness of this procedure across various ages of implantation—a choice parameter for parents and clinicians with high prognostic value for clinical outcome. As such, the aim of the present study is to evaluate a model of the consequences of the timing of this intervention from a societal economic perspective. Average cost utility of pediatric CI by age at intervention will be analyzed. Design: Prospective, longitudinal assessment of health utility and educational placement outcomes in 175 children recruited from six U.S. centers between November 2002 and December 2004, who had severe-to-profound SNHL onset within 1 year of age, underwent CI before 5 years of age, and had up to 6 years of postimplant follow-up that ended in November 2008 to December 2011. Costs of care were collected retrospectively and stratified by preoperative, operative, and postoperative expenditures. Incremental costs and benefits of implantation were compared among the three age groups and relative to a nonimplantation baseline. Results: Children implanted at 36 months of age, respectively. Medical and surgical complication rates were not significantly different among the three age groups. In addition, mean lifetime costs of implantation were similar among the three groups, at approximately $2000/child/year (77.5-year life expectancy), yielding costs of $14,996, $17,849, and $19,173 per QALY for the youngest, middle, and oldest implant age groups, respectively. Full mainstream classroom integration rate was significantly higher in the youngest group at 81% as compared with 57 and 63% for the middle and oldest groups, respectively (p < 0.05) after 6 years of follow-up. After incorporating lifetime educational cost savings, CI led to net societal savings of $31,252, $10,217, and $6,680 for the youngest, middle, and oldest groups at CI, respectively, over the child’s projected lifetime. Conclusions: Even without considering improvements in lifetime earnings, the overall cost-utility results indicate highly favorable ratios. Early (<18 months) intervention with CI was associated with greater and longer qualityof-life improvements, similar direct costs of implantation, and economically valuable improved classroom placement, without a greater incidence of medical and surgical complications when compared to CI at older ages. (Ear & Hearing 2013;01;0–0)

Consensus statement: Eriksholm workshop on wideband absorbance measures of the middle ear

Abstract: The participants in the Eriksholm Workshop on Wideband Absorbance Measures of the Middle Ear developed statements for this consensus article on the final morning of the Workshop. The presentations of the first 2 days of the Workshop motivated the discussion on that day. The article is divided into three general areas: terminology; research needs; and clinical application. The varied terminology in the area was seen as potentially confusing, and there was consensus on adopting an organizational structure that grouped the family of measures into the term wideband acoustic immittance (WAI), and dropped the term transmittance in favor of absorbance. There is clearly still a need to conduct research on WAI measurements. Several areas of research were emphasized, including the establishment of a greater WAI normative database, especially developmental norms, and more data on a variety of disorders; increased research on the temporal aspects of WAI; and methods to ensure the validity of test data. The area of clinical application will require training of clinicians in WAI technology. The clinical implementation of WAI would be facilitated by developing feature detectors for various pathologies that, for example, might combine data across ear-canal pressures or probe frequencies.

Assessment of Ear Disorders Using Power Reflectance

Abstract: This article describes the effect of various pathologies on power reflectance (PR) and absorbance measured in human adults. The pathologies studied include those affecting the tympanic membrane, the middle-ear ossicles, the middle-ear cavity, the inner ear, and intracranial pressure. Interesting pathology-induced changes in PR that are statistically significant have been reported. Nevertheless, because measurements of PR obtained from normal-hearing subjects have large variations and some pathology-induced changes are small, it can be difficult to use PR alone for differential diagnosis. There are, however, common clinical situations without reliable diagnostic methods that can benefit from PR measurements. These conditions include ears with a normal-appearing tympanic membrane, aerated middle-ear cavity, and unknown etiology of conductive hearing loss. PR measurements in conjunction with audiometric measurements of air–bone gap have promise in differentiating among stapes fixation, ossicular discontinuity, and superior semicircular canal dehiscence. Another possible application is to monitor an individual for possible changes in intracranial pressure. Descriptions of mechanisms affecting PR change and utilization of PR measurements in clinical scenarios are presented.

An overview of wideband immittance measurements techniques and terminology: you say absorbance, I say reflectance.

Abstract: This article reviews the relationships among different acoustic measurements of the mobility of the tympanic membrane, including impedance, admittance, reflectance, and absorbance, which the authors group under the rubric of immittance measures. Each of these quantities is defined and related to the others. The relationship is most easily grasped in terms of a straight rigid ear canal of uniform area terminated by a uniform middle ear immittance placed perpendicular to the long axis of the ear canal. Complications due to variations from this geometry are discussed. Different methods for measuring these quantities are described, and the assumptions inherent within each method are made explicit. The benefits of wideband measurements of these quantities are described, as are the benefits and limitations of different components of immittance and reflectance/absorbance. While power reflectance (the square of the magnitude of pressure reflectance) is relatively invariant along the length of the ear canal, it has the disadvantage that it ignores phase information that may be useful in assessing the presence of acoustic leaks in ear-canal measurements and identifying other potential error sources. A combination of reflectance and impedance magnitude and angle give a more complete description of the middle ear from measurements in the ear canal.

Repeatability of click-evoked otoacoustic emission-based medial olivocochlear efferent assay.

Abstract: Objectives Otoacoustic emissions-based efferent assays are evolving to become a part of auditory diagnostics. The wide range of clinical applications, such as assessment of auditory neuropathy, auditory processing disorders, learning disability, monitoring success in auditory intervention and others illustrate the significance of this measurement. Defining the procedure's test-retest repeatability is of critical importance, to allow for distinction between measurement deviations and true physiological or pathological changes. The purpose of this study was to assess the repeatability of a click-evoked otoacoustic emission-based (CEOAE) test of the medial olivocochlear (MOC) reflex in normal-hearing (NH) adults. Design Test-retest data were collected from 35 NH young adults in two distinct test sessions separated by 1 to 4 days. CEOAEs were recorded without and with contralateral acoustic stimulation (CAS; 35 dB SL). Three indices of the MOC reflex were computed: CAS-induced (a) absolute changes in CEOAE amplitude, (b) normalized changes in CEOAE amplitude, and (c) changes in CEOAE input-output functions. Repeatability of these indices was assessed by a three-layered approach, which consisted of Bland-Altman plots, coefficient of reliability (Cronbach's α), and analysis of variance. Results Analyses indicated good repeatability of three CEOAE-based MOC reflex indices. A two-way analysis of variance of the indices demonstrated no significant difference between test and retest. Normalized index showed similar repeatability as other indices. CEOAE signal to noise ratio did not seem to vary between test sessions. Notably, CAS caused a decrease in CEOAE input-output functions slope in a majority of participants (n = 29). Conclusions The present study is the first to elucidate the intrasubject variability of absolute and normalized indices of the MOC inhibitory effect. Although the measurements were conducted under realistic conditions resembling the clinical setting, repeatability was generally good in NH adults. For MOC reflex test, the signal to noise ratio of 6 dB for recording CEOAEs seems to be a recommendable criterion when considering practicability and measurement quality in clinical conditions. The present findings exemplify the suitability of CEOAE-based MOC assay as a monitoring tool of medial efferent status over time. The data are intended to assist clinicians and scientists alike in the accurate interpretation of CAS-induced CEOAE changes in the test-retest situation.

An Adaptive Australian Sentence Test in Noise (AuSTIN)

Abstract: Objectives:The aim of this research is to describe the development of an adaptive Australian Sentence Test in Noise and to validate the test in terms of test–retest reliability and efficiency using data obtained from its clinical application.Design:The relative intelligibility of 1264 Bamford-Kowal-

Efficient hearing screening in noise-exposed listeners using the digit triplet test.

Abstract: Objectives Hearing screening in occupational medicine is generally based on pure-tone threshold audiometry. However, reliable and valid thresholds can only be obtained in a sound-proof room, using a high-quality, well-calibrated audiometer, and by a well-trained administrator. Thresholds also need to be determined for several audiometric frequencies. This makes the test time-consuming and expensive, which is not ideal for the screening of large populations. A Speech-In-Noise test (SPIN), by contrast, does not have the abovementioned requirements. Because it can be implemented as a quick automated self-test, possibly over the Internet, a SPIN test is highly advantageous for screening purposes. However, its sensitivity for (isolated) high-frequency hearing loss, as typically seen in noise-exposed listeners, was unclear up to present. In this study, the authors investigated the sensitivity and specificity of the Digit Triplet SPIN test for detecting and monitoring (early-stage) high-frequency hearing loss, and its similarity across two different language versions. Design One-hundred eighteen noise-exposed workers, representing a wide range from no to severe high-frequency hearing loss, completed the French or Dutch version of the broadband Digit Triplet self-test in an office-like room. Pure-tone thresholds, collected by a professional audiologist in favorable settings, served as the reference. Results The 84 Dutch-speaking participants showed a very strong linear relation between the reference and the Digit Triplet test, with the pure-tone average at 2, 3, 4, and 6 kHz as a strong predictor (R = 0.86) for the speech-reception threshold. The sensitivity and specificity to detect mild high-frequency hearing loss were 92% (61 of 66) and 89% (16 of 18), respectively. The area under the receiver operating characteristic (ROC) curve was very high (≥0.91) for several degrees of high-frequency hearing loss. With a within-subject standard deviation of only 0.8 dB, the Digit Triplet test also had a low measurement error. The results of the 34 French-speaking subjects showed a highly similar trend. Conclusions The Digit Triplet test proves to have a high sensitivity and specificity for detecting different degrees of high-frequency hearing loss. Given its ease of use, this test is very suitable for screening purposes in occupational medicine, and potentially for the screening of adolescents at risk of recreational noise-induced hearing loss.