The importance of acoustic reflex for communication

Ear and Hearing, 2013

The objective of this study was to examine the role of the acoustic stapedius reflex in the protection of speech recognition from the upward spread of masking arising from low-frequency background noise. Speech recognition scores were measured for nine control participants (19-34 years) and six patients with transected stapedius tendons poststapedotomy (39-57 years) as a function of the amplitude of a low-frequency masker, presented at nominal signal to noise ratios of +5 dB, -5 dB, and -15 dB. All participants had pure-tone hearing thresholds in the normal range. Continuous high-pass noise was present in all conditions to avoid ceiling effects; this reduced performance in quiet to approximately 85% for all participants. Scores were measured for soft and loud nonsense syllables (average third octave band levels of 35 and 65 dB SPL), so that a comparison of the low-frequency noise masking functions at the two levels would provide information about the effects of the reflex on speech intelligibility in noise. A third group of nine control participants (19-22 years) listened in the presence of a low-frequency masker gated to come on 1 sec before stimulus onset, to reduce the likelihood of reflex adaptation. The Speech-Intelligibility Index was used to quantify the amount of speech information available in each condition. Patients with transected tendons performed more poorly than control participants as a function of Speech-Intelligibility Index in all conditions, even at levels that were too soft for reflex activation. This could be because of postsurgical differences in sensitivity, the more advanced age of poststapedotomy group, or differences in medial olivocochlear inhibition. For loud speech, patient performance fell nearly linearly with increases in the low-frequency masker, but control participants' performance declined little as the signal to noise ratio declined from +5 to -5 dB, and then fell rapidly as the ratio declined to -15 dB. This plateau in the masking function did not occur for the patients. Masking functions obtained with the gated low-frequency masker were either highly similar or poorer to those obtained with a continuous masker, suggesting that the use of a continuous low frequency masker did not result in significant reflex adaptation. The stapedius reflex appears to offer some protection from the upward spread of masking of speech by background low-frequency noise at moderate levels, but not at high levels.

Speech, Language and Hearing, 2014

Purpose: To investigate the effect of female versus male speakers' voice on the ability to recognize speech in noise in two groups of sensorineural hearing-impaired listeners, one group with impairment at low frequencies and the other at high frequencies. Method: Eight participants with high-frequency hearing impairments (Hf-HI) and seven with low-frequency hearing impairments participated. Sixteen normal hearing (NH) participants served as reference. The sentences from the hearing in noise test, read by a female or a male speaker, were presented monaurally with a background noise. In an adaptive procedure, the mean speech recognition threshold, for 50% correctly recognized sentences, was calculated for the female and male voice and each test subject. Results: The Hf-HI group had significantly greater difference in signal-to-noise ratio (SNR) results between female and male voices. Irrespective of hearing impairment, the female voice required 2.1 dB better SNR. In addition, the NH group showed a small but significant difference in favor of the male voice. Conclusions: Results indicate that speaker gender matters for hearing impaired and NH individuals' ability to recognize speech in noise.

Journal of the American Academy of Audiology, 1994

This study addressed the issue of whether functional impairments can be identified or confirmed using tonal acoustic reflex thresholds (ARTs). Tonal ARTs from 74 ears with functional impairments were compared to 10th percentiles of the ARTs for normal and cochlear-impaired ears at 500 to 2000 Hz (Gelfand, Schwander, and Silman, 1990). Only one ear (5.3%) was correctly identified among the 19 ears in which all of the voluntary thresholds at 500 to 2000 Hz were < or = 55 dB HL. Acoustic reflex thresholds correctly identified functional losses in 70.9 percent, 78.6 percent, and 85.7 percent of the ears with voluntary thresholds > or = 60 dB HL at one, two, or three of these frequencies, respectively. The false positive rate was only 5 to 7 percent for a control group of 50 ears with genuine sensorineural hearing losses. The results indicate that tonal ARTs are an effective nonbehavioral tool for identifying or substantiating the presence of functional losses when thresholds are &...

International Journal of Audiology, 2005

Comprensió n del lenguaje en silencio y con ruido, con y sin auxiliares auditivos Abstract Speech recognition and cognitive functions important for speech understanding were evaluated by objective measures and by scores of perceived effort, with and without hearing aids. The tests were performed in silence, and with background conditions of speech spectrum random noise and ordinary speech. One young and one elderly group of twelve hearing-impaired subjects each participated. Hearing aid use improved speech recognition in silence (7 dB) and in the condition with speech as background (2.5 dB S/N), but did not change the perceived effort scores. In the cognitive tests no hearing aid benefit was seen in objective measures, while there was an effect of hearing aid use in scores of perceived effort, subjects reported less effort. There were no age effects on hearing aid benefit. In conclusion, hearing aid use may result in reduced effort in listening tasks that is not associated with improvement in objective scores.

Juniper, 2017

Acoustic Reflex Latency (ARL) is the time interval between onset of an intense auditory stimulus and onset of middle-ear muscle contraction. Unlike pure tone audiogram, the usual procedure to detect middle ear disorders and conductive hearing loss, ARL can differentiate between cochlear and retrocochlear pathologies, yields information about the nature of the conductive disorder, can detect mild conductive problems and is useful for patients that require cooperation. The present study done on 30 normal-hearing female subjects between the age range of 20-30 years old shows no significant differences between the results in the left and right ears of the subjects using the Acoustic Reflex Threshold (ART) latency parameters tested from 500 Hz to 4,000 Hz and the Interaural Latency Difference (ILD) for initial latency of 500 Hz with ILD for initial latency of other frequencies. The present study might be used as normative data for future research on ARL in patients with various cochlear and retrocochlear lesions as part of a differential diagnosis.

Brazilian Journal of Otorhinolaryngology, 2016

Introduction: Hearing loss can negatively influence the communication performance of individuals, who should be evaluated with suitable material and in situations of listening close to those found in everyday life. Objective: To analyze and compare the performance of patients with mild-to-moderate sensorineural hearing loss in speech recognition tests carried out in silence and with noise, according to the variables ear (right and left) and type of stimulus presentation. Methods: The study included 19 right-handed individuals with mild-to-moderate symmetrical bilateral sensorineural hearing loss, submitted to the speech recognition test with words in different modalities and speech test with white noise and pictures. Results: There was no significant difference between right and left ears in any of the tests. The mean number of correct responses in the speech recognition test with pictures, live voice, and recorded monosyllables was 97.1%, 85.9%, and 76.1%, respectively, whereas after the introduction of noise, the performance decreased to 72.6% accuracy. Conclusions: The best performances in the Speech Recognition Percentage Index were obtained using monosyllabic stimuli, represented by pictures presented in silence, with no significant differences between the right and left ears. After the introduction of competitive noise, there was a decrease in individuals' performance.

Otorhinolaryngology-Head and Neck Surgery, 2018

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Brazilian Journal of Otorhinolaryngology, 2015

Introduction: The clinical evaluation of subjects with occupational noise exposure has been difficult due to the discrepancy between auditory complaints and auditory test results. This study aimed to evaluate the contralateral acoustic reflex thresholds of workers exposed to high levels of noise, and to compare these results to the subjects' auditory complaints. Methods: This clinical retrospective study evaluated 364 workers between 1998 and 2005; their contralateral acoustic reflexes were compared to auditory complaints, age, and noise exposure time by chi-squared, Fisher's, and Spearman's tests. Results: The workers' age ranged from 18 to 50 years (mean = 39.6), and noise exposure time from one to 38 years (mean = 17.3). We found that 15.1% (55) of the workers had bilateral hearing loss, 38.5% (140) had bilateral tinnitus, 52.8% (192) had abnormal sensitivity to loud sounds, and 47.2% (172) had speech recognition impairment. The variables hearing loss, speech recognition impairment, tinnitus, age group, and noise exposure time did not show relationship with acoustic reflex thresholds; however, all complaints demonstrated a statistically significant relationship with Metz recruitment at 3000 and 4000 Hz bilaterally. Conclusion: There was no significance relationship between auditory complaints and acoustic reflexes.

International Journal of Audiology, 2017

Objective: To determine whether acoustic reflexes are pervasive (i.e., known with 95 % confidence to be observed in at least 95 % of people) by examining the frequency of occurrence using a friction-fit diagnostic middle ear analyzer. Design: A group of 285 adult participants with very good hearing sensitivity underwent audiometric and middle ear testing. Acoustic reflexes were tested ipsilaterally and contralaterally in both ears across a range of elicitor frequencies. Two automated methods were used to detect the presence of an acoustic reflex. Results: There were no conditions in which the proportion of participants exhibiting acoustic reflexes was high enough to be deemed pervasive. Ipsilateral reflexes were more likely to be observed than contralateral reflexes and reflexes were more common at .5 and 1 kHz elicitor frequencies as compared to 2 and 4 kHz elicitor frequencies. Conclusions: Acoustic reflexes are common among individuals with good hearing. However, acoustic reflexes cannot be considered pervasive and should not be included in damage risk criteria and health hazard assessments for impulsive noise.

Ear and Hearing, 1984

This is a clearly written book whose topic coverage is distinctly nontraditional. The author hopes the "book will be of value to research scientists and to professionals working in speech and hearing." Also "basic information necessary for understanding the material covered is provided, so that it may be used in courses for advanced undergraduate and graduate students in behavioral sciences, neurobiology, engineering, and the health sciences and professions" (p. xiii). Authors' hopes as to the applicability and appeal of their writing are notoriously high; this seems to be no exception. While it is possible that it might serve as a supplemental text in a limited number of courses, it is unlikely that many instructors would find it satisfactory as a primary text. The reason for this is the topic coverage which, for the most part, is a compendium of the author's own research. After an introductory chapter on acoustics, anatomy, and physiology (30 pp.), seven other chapters follow. They are spatial localization and binaural hearing (25 pp.), perception of acoustic repetition-primarily pitch effects (45 pp.

Scientific Reports, 2022

Understanding speech in background noise is challenging. Wearing face-masks, imposed by the COVID19-pandemics, makes it even harder. We developed a multi-sensory setup, including a sensory substitution device (SSD) that can deliver speech simultaneously through audition and as vibrations on the fingertips. The vibrations correspond to low frequencies extracted from the speech input. We trained two groups of non-native English speakers in understanding distorted speech in noise. After a short session (30–45 min) of repeating sentences, with or without concurrent matching vibrations, we showed comparable mean group improvement of 14–16 dB in Speech Reception Threshold (SRT) in two test conditions, i.e., when the participants were asked to repeat sentences only from hearing and also when matching vibrations on fingertips were present. This is a very strong effect, if one considers that a 10 dB difference corresponds to doubling of the perceived loudness. The number of sentence repetiti...

Korean Journal of Audiology, 2014

This study investigated the effect of ageing on speech perception in quiet and in noise, with noise directed from front, right and left. Subjects and Methods: Sixty Malay native adults with normal or near normal hearing comprising of 20 young adults (21 to 39 years old), 20 middle aged (40 to 59 years old) and 20 older adults (60 to 74 years old) participated in this study. Their speech perception ability was measured using the Malay Hearing in Noise Test (HINT) in four test conditions; 1) in quiet (HINT Q), 2) with noise from front (HINT NF), 3) with noise from right (HINT NR), and 4) with noise from left (HINT NL). Reception thresholds for sentences (RTSs) were measured in each of the aforementioned conditions using an adaptive method. Results: The results showed that, 1) genuine age-related decline was found in speech perception performance in HINT (NF), 2) hearing threshold was a major determinant differentiating speech perception performance for HINT (Q) and HINT (NL) conditions, and 3) speech perception performance for HINT (NR) was determined by both age and hearing threshold. Conclusions: This study suggests that, in older adults, while hearing thresholds affect speech perception in quiet, other factors such as central auditory processing and cognitive functions might be more important determinant factors for speech perception performance in noise.

The Journal of the Acoustical Society of America, 1975

The purpose.of this investigation was to compare the effects of temporal auditory integration on the acoustic reflex thresholds for subjects with normal hearing and for subjects with noise-induced permanent threshold shift. Threshold-duration functions were determined for 1, 2,.and 4 KHz pure tones and for broad-band noise. Acoustic reflexes were monitored using an impedance technique. Stimulus durations employed were 20, SO, 100, .200, and 500 msec. A measurement technique was developed which included observation of the impedance bridge output deflections in conjunction with latency time to confirm the occurrence of reflex activity. Res ults of the study indicated that there may be flattening of acoustic reflex threshold�duration functions for persons having noise-induced hearing los se�� Flattened functions appeared to be frequency specific and corresponded to areas of hearing los s. The degree of flattening of the functions was related to the degree of the hearing los s, with flatter functions occurring for greater hearing losses. ii �197693

Journal of the American Academy of Audiology, 2004

In this study, the performance of 48 listeners with normal hearing was compared to the performance of 46 listeners with documented hearing loss. Various conditions of directional and omnidirectional hearing aid use were studied. The results indicated that when the noise around a listener was stationary, a first-or second-order directional microphone allowed a group of hearingimpaired listeners with mild-to-moderate, bilateral, sensorineural hearing loss to perform similarly to normal hearing listeners on a speech-in-noise task (i.e., they required the same signal-to-noise ratio to achieve 50% understanding). When the noise source was moving around the listener, only the second-order (three-microphone) system set to an adaptive directional response (where the polar pattern changes due to the change in noise location) allowed a group of hearing-impaired individuals with mild-to-moderate sensorineural hearing loss to perform similarly to young, normal-hearing individuals.

The Journal of the Acoustical Society of America, 1994

The effect of articulating clearly on speech intelligibility is analyzed for ten normal-hearing and two hearing-impaired listeners in noisy, reverberant, and combined environments. Clear speech is more intelligible than conversational speech for each listener in every environment. The difference in intelligibility due to speaking style increases as noise and/or reverberation increase. The average difference in intelligibility is 20 percentage points for the normal-hearing listeners and 26 percentage points for the hearing-impaired listeners. Two predictors of intelligibility are used to quantify the environmental degradations: The articulation index (AI) and the speech transmission index (STI). Both are shown to predict, reliably, performance levels within a speaking style for normal-hearing listeners. The AI is unable to represent the reduction in intelligibility scores due to reverberation for the hearing-impaired listeners. Neither predictor can account for the difference in inte...