The present paper provides an overview of research concerning both acute and chronic effects of exposure to noise on children's cognitive performance. Experimental studies addressing the impact of acute exposure showed negative effects on speech perception and listening comprehension. These effects are more pronounced in children as compared to adults. Children with language or attention disorders and second-language learners are still more impaired than age-matched controls. Noise-induced disruption was also found for non-auditory tasks, i.e., serial recall of visually presented lists and reading. The impact of chronic exposure to noise was examined in quasi-experimental studies. Indoor noise and reverberation in classroom settings were found to be associated with poorer performance of the children in verbal tasks. Regarding chronic exposure to aircraft noise, studies consistently found that high exposure is associated with lower reading performance. Even though the reported effects are usually small in magnitude, and confounding variables were not always sufficiently controlled, policy makers responsible for noise abatement should be aware of the potential impact of environmental noise on children's development.

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Does noise affect learning? A short review on noise effects on cognitive performance in children

ObjectivesRecently, several studies have shown that a cochlear implant is a suitable treatment for hearing rehabilitation of adults with unilateral sensorineural hearing loss (UHL), and benefits for speech comprehension in noise and localization have been demonstrated. The aim of this clinical study

Unilateral deafness in children: audiologic and subjective assessment of hearing ability after cochlear implantation.

The effects of noise on students’ health, well-being, and learning are of growing concern among both the general public and policy-makers in Europe. Several studies have highlighted the consequences of noise on children’s learning and performance at school. This study investigates the relationship between noise judgment in school goers aged 11–18 and noise measurements aimed at evaluating their exposure at school. For this purpose, a questionnaire was administered to 521 individuals in 28 classrooms in eight schools of four cities in Italy, with different environmental characteristics. Using a Likert-type scale, a selected set of responses related to noise generated an Annoyance Index (AI) score for each student and a classroom median score (MAI). From the noise data acquired, a global noise score (GNS) was assigned to each classroom. A higher AI was found in industrialized areas and among younger students. No significant differences in noise judgment were found by gender. A significant inverse correlation was described between MAI and GNS, thus the better the acoustic quality of the classrooms, the less the perceived noise and annoyance. The results show that noise perception and consequent disturbance are highly correlated with classroom acoustics, and confirm that annoyance represents the most widespread subjective response to noise.

Annoyance Judgment and Measurements of Environmental Noise: A Focus on Italian Secondary Schools

The potential effects of acoustical environment on speech understanding are especially important as children enter school where students’ ability to hear and understand complex verbal information is critical to learning. However, this ability is compromised because of widely varied and unfavorable classroom acoustics. The extent to which unfavorable classroom acoustics affect children’s performance on longer learning tasks is largely unknown as most research has focused on testing children using words, syllables, or sentences as stimuli. In the current study, a simulated classroom environment was used to measure comprehension performance of two classroom learning activities: a discussion and lecture. Comprehension performance was measured for groups of elementary-aged students in one of four environments with varied reverberation times and background noise levels. The reverberation time was either 0.6 or 1.5 s, and the signal-to-noise level was either +10 or +7 dB. Performance is compared to adult subjects as well as to sentence-recognition in the same condition. Significant differences were seen in comprehension scores as a function of age and condition; both increasing background noise and reverberation degraded performance in comprehension tasks compared to minimal differences in measures of sentence-recognition.

Experimental investigation of the effects of the acoustical conditions in a simulated classroom on speech recognition and learning in children

Non-intrusive speech intelligibility metrics are based solely on the corrupted speech information and a prior model of the speech signal in a given representation As such, any sources of variability not taken into account by the model will affect the metric's per-formance In this paper, we investigate two sources of variability in the auditory-inspired model used by the speech-to-reverberation modulation energy ratio (SRMR) metric, namely speech content and pitch, and propose two updates that aim to reduce the variability caused by these sources First, we limited the dynamic range of the energies in the modulation spectrum bands in order to reduce the effect of speech content and speaker variability Second, the range of the modulation filter bank was modified to reduce the variability due to pitch Experimental results show that the updated metric presents higher performance and lower variability relative to the original SRMR when assessing speech intelligibility in noisy and reverberant environments, as well as outperforms several standard intrusive and non-intrusive benchmark metrics

/pdf/an-improved-non-intrusive-intelligibility-metric-for-noisy-1z4qmuhl4f.pdf

An improved non-intrusive intelligibility metric for noisy and reverberant speech

Objectives:The purpose of this study is to determine how combinations of noise levels and reverberation typical of ranges found in current classrooms will affect speech recognition performance of typically developing children with normal speech, language, and hearing and to compare their performance

Combined effects of noise and reverberation on speech recognition performance of normal-hearing children and adults.

This invention presents a noise cancellation device for improved personal face-to-face and radio communications in high noise environments. The device comprises speech acquisition components, an audio signal processing module, a loudspeaker, and a radio interface. With the noise cancellation device, the signal-to-noise ratio can be improved by as much as 30 dB.

Noise cancellation device for communications in high noise environments

Purpose To determine the feasibility of using a virtual auditory test material to evaluate reverberation and noise effects on speech recognition of pediatric cochlear implant (CI) users and to comp...

Measuring Speech Recognition in Children With Cochlear Implants in a Virtual Classroom

Objectives to characterize differences in wideband power reflectance for ears with and without cochlear implants (CIs), to describe electrically evoked stapedial reflex (eSR)-induced changes in reflectance, and to evaluate the benefit of a broadband probe for reflex threshold determination for CI recipients. It was hypothesized that reflectance patterns in ears with CIs would be consistent with increased middle ear stiffness and that reflex thresholds measured with a broadband probe would be lower compared with thresholds obtained with a single-frequency probe. Design Eleven CI recipients participated in both wideband reflectance and eSR testing. Ipsilateral reflexes were measured with three probes: a broadband chirp (swept from 200 to 8000 Hz), a 226 Hz tone, and a 678 Hz tone. Wideband reflectance measures acquired from 28 adults without CIs and with normal middle ear function served as a normative data set for comparison. Results Considering the group data, average reflectance was significantly greater for ears with CIs across 250 to 891 Hz and 4238 to 4490 Hz compared with the normative data set, although individual reflectance curves were variable. Some CI recipients also had low 226 Hz admittance, which contributed to the group finding, considering the control group had clinically normal 226 Hz admittance by design. Electrically evoked stapedial reflexes were measurable in nine of 14 ears (64.3%) and in 24 of 46 electrodes (52.5%) tested. Reflex-induced changes in reflectance patterns were unique to the participant/ear, but similar across activators (electrodes) within a given ear. In addition, reflectance values at or above 1000 Hz were affected most by activating the stapedial reflex, even in ears with clinically normal 226 Hz admittance. This is a higher-frequency range than has been reported for acoustically evoked reflex-induced reflectance changes and is consistent with increased middle ear stiffness at rest. Electrically evoked reflexes could be measured more often with the 678 Hz or the broadband probe compared with the 226 Hz probe tone. Although reflex thresholds were lower with the broadband probe compared with the 678 Hz probe in 16 of 24 conditions, this was not a statistically significant finding (Wilcoxon signed-rank test; p = 0.072). Conclusions The applications of wideband acoustic immittance measurements (reflectance and reflexes) should also be considered for ears with CIs. Further work is needed to describe changes across time in ears with CIs to more fully understand the reflectance pattern indicating increased middle ear stiffness and to optimize measuring eSRs with a broadband probe.

Wideband Acoustic Immittance in Cochlear Implant Recipients: Reflectance and Stapedial Reflexes

Objective test methods were developed to quantify and assess the effects of personal protection equipment on auditory situational awareness. The tests utilize a custom head and torso simulator that is able to don personal protective equipment and employs acoustics, signal processing, and measurement techniques. The tests measure localization and speech intelligibility effects of personal protective equipment such as air purifying respirators, helmets, chemical protective jackets, and powered air purifying respirators. These methods also quantify the effects of noise generated by personal protective equipment electro/mechanical noise. Localization effects are evaluated in terms of the head-related transfer function. Speech intelligibility is evaluated using the speech transmission index. Results indicate that some types of head-borne personal protective equipment lead to significant distortions to the head-related transfer function and decreased speech transmission index scores, consequently altering auditory situational awareness.

Joshua J. Hajicek

Papers

Combined effects of noise and reverberation on speech recognition performance of normal-hearing children and adults.

Noise cancellation device for communications in high noise environments

Measuring Speech Recognition in Children With Cochlear Implants in a Virtual Classroom

Wideband Acoustic Immittance in Cochlear Implant Recipients: Reflectance and Stapedial Reflexes

Protocols for improved understanding of situational awareness effects of head-borne PPE