Showing papers in "Journal of Medical Speech-language Pathology in 2004"

Algorithmic Estimation of Pauses in Extended Speech Samples of Dysarthric and Typical Speech.

Abstract: The aim of this study was to evaluate the validity and performance of an algorithm designed to automatically extract pauses and speech timing information from connected speech samples. Speech samples were obtained from 10 people with amyotrophic lateral sclerosis (ALS) and 10 control speakers. Pauses were identified manually and algorithmically from digitally recorded recitations of a speech passage that was developed to improve the precision of pause boundary detection. The manual and algorithmic methods did not yield significantly different results. A stepwise analysis of three different pause detection parameters revealed that estimates of percent pause time were highly dependent on the values specified for the minimum acceptable pause duration and the minimum signal amplitude. Consistent with previous reports of dysarthric speech, pauses were significantly longer and more variable in speakers with ALS than in the control speakers. These results suggest that the algorithm provided an efficient and valid method for extracting pause and speech timing information from the optimally structured speech sample.

Diagnostic Assessment of Childhood Apraxia of Speech Using Automatic Speech Recognition (ASR) Methods.

Abstract: We report findings from two feasibility studies using automatic speech recognition (ASR) methods in childhood speech sound disorders. The studies evaluated and implemented the automation of two recently proposed diagnostic markers for suspected Apraxia of Speech (AOS) termed the Lexical Stress Ratio (LSR) and the Coefficient of Variation Ratio (CVR). The LSR is a weighted composite of amplitude area, frequency area , and duration in the stressed compared to the unstressed vowel as obtained from a speaker’s productions of eight trochaic word forms. Composite weightings for the three stress parameters were determined from a principal components analysis. The CVR expresses the average normalized variability of durations of pause and speech events that were obtained from a conversational speech sample. We describe the automation procedures used to obtain LSR and CVR scores for four children with suspected AOS and report comparative findings. The LSR values obtained with ASR were within 1.2% to 6.7% of the LSR values obtained manually using Computerized Speech Lab (CSL). The CVR values obtained with ASR were within 0.7% to 2.7% of the CVR values obtained manually using Matlab. These results indicate the potential of ASR-based techniques to process these and other diagnostic markers of childhood speech sound disorders.

The Effect of Three Practice Conditions on the Consistency of Chronic Dysarthric Speech

Abstract: This study investigated whether it is possible for people with chronic dysarthria to adjust their articulation in three practice conditions. A speaker dependent, speech recognition system was used to compare participants' practice attempts with a model of a word made from previous recordings to give a recognition score. This score was used to indicate changes in production of practice words with different conditions. The three conditions were reading of written target words, visual feedback, and an auditory model followed by visual feedback. For eight participants with dysarthria, the ability to alter speech production was shown, together with a differential effect of the three conditions. Copying an auditory target gave significantly better recognition scores than just repeating the word. Visual feedback was no more effective than repetition alone. For four control participants, visual feedback did produce significantly better recognition scores than just repetition of written words, and the presence of an auditory model was Significantly more effective than visual feedback. Possible reasons for differences between conditions are discussed.

Evaluating the role of speech-language pathology with patients with communication disability in the acute hospital setting using the ICF

Abstract: The practice of speech-language pathology in the acute care hospital setting has changed dramatically over the last 20 years. Speech-language pathologists now routinely assess and manage patients with dysphagia as well as patients with acquired communication disorders. In practice, clinicians have tended to direct their limited resources toward the assessment and management of patients with dysphagia before addressing the needs of patients with acquired communication disorders. This practice has resulted in a decline in speech-language pathology services for patients with communication disorders and has led some clinicians to question the role of the speech-language pathologist in the acute care hospital setting. This article continues this discussion by evaluating the role of the speech-language pathologist in the acute care hospital setting within the context of the World Health Organization's (WHO) International Classification of Functioning, Disability and Health (ICF; WHO, 2001). It argues that by adopting the ICF, speech-language pathologists have a sound rationale for broadening their role to identify the communication needs of all hospital inpatients who experience communication difficulties in the acute care hospital setting.

The effects of delayed and frequency shifted feedback on speakers with Parkinson disease

Abstract: Delayed auditory feedback (DAF) has been assessed as a rate reduction and intelligibility enhancing tool in patients with Parkinson disease (PD) for some time. However, there are contradictory results in the literature regarding the success of this device. Also, little is known about the effects of DAF on speech other than influences on speech rate and intelligibility. Frequency shifted feedback (FSF) is known to produce more natural sounding speech than DAF and to improve the fluency of persons who stutter. However, there are currently no studies reporting how PD speakers perform under FSF. The aim of this study was to investigate the effects of both types of altered feedback on the speech of PD and control participants on a broad range of measures. The performance of 16 PD speakers and 11 control speakers in a reading task under DAF, FSF, and no altered feedback (NAF) are reported here. The results showed that all groups responded to altered feedback in a similar way and showed a prominent reduction of speech rate. The conditions evoked changes in pause frequency (increases), loudness levels (increases), pitch variation (increases), and intelligibility and naturalness (decreases) for all or some of the groups. Few effects could be observed on articulation/pause time ratio, pause duration, pitch range, and speech rhythm. Previous reports on differences in susceptibility of PD speaker to altered feedback were confirmed, and some speakers benefited from the system despite the negative group results for intelligibility and naturalness. In general, FSF resulted in performance closer to the NAF state than to DAF on all variables, and for those PD speakers who benefited from altered feedback, the FSF condition evoked the greatest improvement.

Speech-Breathing Treatment and LSVT for a Patient With Hypokinetic-Spastic Dysarthria After TBI.

Abstract: The Lee Silverman Voice Treatment® (LSVT) program was developed to improve speech in persons with hypokinetic dysarthria associated with Parkinson disease (PD) (Ramig, 1995). It has been tested in a relatively large number of people with PD, and available evidence supports its effectiveness for up to 2 years (Ramig et al., 2001). Less often, LSVT has been used with patients who have other etiologies, including Parkinson-plus syndromes (Countryman, Ramig, & Pawlas, 1994) and multiple sclerosis (Sapir et al., 2001). Results from these cases are guarded by the apparent need to supplement or extend the standard 4-week program and evidence of decreased effectiveness over subsequent months. Previously, we published a case study of a young man who presented with mixed hypokinetic-spastic dysarthria 20 months post-TBI (Solomon et al., 2001). He participated in LSVT followed by 6 weeks of Combination Treatment that included speech-breathing training, physical therapy, and LSVT-type tasks. The additional treatment was deemed necessary because of minimal improvement in speech breathing and speech intelligibility following LSVT alone. Marked improvements resulted after the full 10-week program, and these gains were maintained for several months. To further examine the viability of LSVT as a treatment strategy for patients with mixed hypokinetic-spastic dysarthria, we replicated the study in a similar patient. In contrast to the previous study, we simplified the Combination Treatment to focus only on nonspeech and speech breathing, conducted treatments in reverse order, and included multiple baseline assessments. Data also were collected after 6 weeks of Breathing-for-Speech Treatment (BST), after the 4-week LSVT program, and 1- and 4-months posttreatment.

Jaw and finger movements during visual and auditory motor tracking in Parkinson disease

Abstract: Audiomotor and visuomotor tracking paradigms were used to evaluate differences in oral and upper limb motor deficits in Parkinson disease (PD). Ten PD subjects and 10 normal controls (NC) used their jaw and index finger to track visual targets and auditory targets. Tracking tasks included (1) stationary target tracking, (2) step tracking, and (3) predictable sinusoidal (.3, .5, .8, 1.1 Hz) tracking. Maximum rates of repetition were also examined. Performance measures included response time, repetition rate, and average tracking error. PD subjects showed a significant impairment on most of the tasks and measures that were examined. None of the primary interactions were significant. These interaction results indicate that PD oral and limb movements showed (1) equivalent reductions in the speed of repetitive movements, (2) equivalent increases in visual and auditory response times, (3) equivalent difficulty in maintaining visual and auditory guided postures, and (4) equivalent difficulty in tracking predictable auditory and visual targets. In general, these results support the hypothesis that speech/oral motor deficits are similar to limb motor deficits in PD. These results also emphasize the importance of equating motor tasks when comparing across different systems (i.e., limb vs. speech/oral, gait vs. upper limb).