Auditory and Vestibular Research
Volume:32 Issue: 2, Spring 2023

The increasing prevalence of Noise-Induced Tinnitus (NIT) is considered one of the major occupational health threats these days. Despite the devastating effect of tinnitus on a subject’s performance, auditory functions and life quality, there is a lack of standard protocol for its diagnosis and management. Furthermore, the mechanisms of NIT are not clear yet. So, this review summarized data on NIT mechanisms as well as questionnaires, behavioral and physiologic assessment tools in NIT studies.

Based on the authors’ research, 27 eligible articles were included in this review. NIT was mainly bilateral with moderate severity with an overall prevalence ranging from 4% to 73.7%. Self-report questionnaires, tinnitus handicap inventory, auditory brainstem response, otoacoustic emissions and speech in noise tests were the most frequent NIT assessment methods in the reviewed studies. Our review highlights increased latencies in brainstem evoked potentials in tinnitus workers, but the knowledge gap about changes at subcortical and cortical levels remains.

This review suggests speech in noise test as a useful extension to routine tinnitus assessment by questionnaires among workers. Due to insufficient studies and inconsistent results in NIT subjects, more electrophysiological research is suggested in large and homogeneous samples.

There is an integration between visual and vestibular systems. Changes in visual inputs can result in different changes in the Vestibulo-Ocular Reflex (VOR). This review study investigate the changes in VOR due to changes in visual inputs. In this regard, the effects of different conditions such as visual deprivation, changes in visual acuity, visual-vestibular conflict, and binocular vision dysfunction on VOR were assessed.

Changes in visual inputs and visual-vestibular conflicts can lead to different changes in VOR.

The changes in VOR effects vary from slight to severe transformation dependent on the time course, severity and duration of changes in visual inputs.

Buffalo model consists of four Central Auditory Processing Disorder (CAPD) categories: decoding, tolerance-fading memory, organization, and integration. Integration is considered as the most complex category. The Dichotic Offset Measure (DOM) provides valuable information about the organization and integration problems. The present study aimed to develop the Persian version of the DOM (P-DOM) and evaluate its psychometric properties in normal-hearing children.

In this study, 25 normal-hearing children (13 girls) aged 7–12 years participated and were divided into six age groups. The face validity was determined based on the opinions of 15 experts, five children with CAPD, and five normal-hearing children. All children were tested with the Persian staggered spondaic word test, Persian phonemic synthesis test, and the Persian randomized dichotic digit test.

The results showed the high face validity of the P-DOM. No significant differences were observed between the scores of girls and boys (p=0.394 for the right non-competing, p=0.623 for the right competing, p=0.155 for the left competing, p=0.066 for the left noncompeting, p=0.174 for the total score, and p=0.701 for the reversals). Significant differences were observed in the main scores of P-DOM test among the age groups. The Spearman test showed a high test-retest reliability (r>0.69).

As a preliminary study it seems that the P-DOM has good validity and reliability to be used in normal-hearing children, but it needs further research with larger sample size.

People with spatial hearing impairment have difficulty perception of speech in the presence of noise, sound localization, and estimating the distance from the sound source. In this study, the comparison between amplitude and latency of the Binaural Interaction Component of the Auditory Brainstem Response (ABR-BIC) with the total score of the Persian version of the Spatial Hearing Questionnaire (SHQ) in adults with normal hearing and moderate sensorineural hearing loss (SNHL) was evaluated.

In this cross-sectional comparative study 55, 18–45-year-old individuals including 35 of normal hearing and 20 moderate SNHL participated. All participants underwent the assessments of medical history, otoscopy, conventional audiometry, tympanometry, SHQ questionnaire, and auditory brainstem response (ABR).

There was no significant correlation between the amplitude and latency of the ABRBIC and the Persian version of the SHQ in normal groups (r=–0.085, r=0.116) and in moderate SNHL groups (r=0.030, r=0.119). The mean value of ABR-BIC range of people with normal hearing and SNHL is statistically significant (p=0.001).

The results showed that the amplitude and latency of ABR-BIC were not correlated with the Persian version of the SHQ in people with normal hearing and with moderate SNHL but statistically significant between the mean amplitude and latency of ABRBIC in people with normal hearing and people with hearing loss.

Psychoacoustics includes studying the perceived effects of changes in sound intensity, temporal, and frequency aspects that are critical for speech perception. Psycon is one such software used in studies to assess psychoacoustic abilities. Psycon has the potential for wide clinical applications in psychoacoustic research and relies on Auditory syntaX (AUX), a program designed specifically to handle auditory signals. The current study aimed to determine the test-retest reliability of the Psycon application for differential sensitivity measures of frequency, intensity, duration and silence.

The study included 39 participants with normal hearing sensitivity. Psychoacoustic measures, namely, gap detection threshold, duration discrimination threshold, difference limen of intensity, and difference limen of frequency, were used to assess test-retest reliability. The test-retest reliability of all measures was checked in two separate sessions within one day.

The reliability of each measure was measured using Cronbach’s alpha. Test-retest reliability of various psychoacoustic tests measured with Psycon ranges from good to excellent. difference limen of frequency had the highest reliability, followed by duration discrimination thresholds, difference limen of intensity, and gap detection thresholds.

Psycon appears to be a reliable tool for assessing different psychoacoustic abilities.

The Acceptance Noise Level (ANL) which determines the tolerable noise level while listening to running speech, is related to factors such as hearing loss and speech presentation level. This study aims to investigate the effect of speech presentation level on the ANL in people with unilateral Meniere’s Disease (MD) compared to the normal-hearing people.

In this study, 33 people aged 32–60 years with unilateral MD and 38 normal-hearing people aged 20–46 years participated. The ANL growth was evaluated unilaterally at four different speech presentation levels: Most Comfortable Level (MCL), –10 dB lower than the MCL, +10 dB higher than the MCL, and a range between MCL and uncomfortable level.

In MD patients, the ANL of the affected ear was significantly different from that of the contralateral ear (p<0.010). Compared to the normal-hearing people, the pattern of ANL growth in MD patients was significantly different, but the ANL growth patterns were similar between the affected and contralateral ears.

ANL and its growth pattern are different between the affected and contralateral ears of patients with unilateral MD, but are similar compared to normal-hearing people. Despite the apparently normal hearing thresholds, the performance of the contralateral ear in noise at various speech presentation levels in patients with unilateral MD seems to be similar to that of the affected ear.

Emotion perception means the ability to identify, predict and explain one’s own emotions and those of others. Less attention has been paid to the psychosocial effects of hearing loss such as emotion perception. The current study aimed to investigate the effect of the unified protocol for transdiagnostic treatment of emotional disorders on emotion perception of children with Cochlear Implant (CI).

This is a quasi-experimental study with a pretest/post-test/follow-up design. Participants were 18 children with CI aged 8–11 years and their mothers were randomly divided into experimental and control groups. All mothers and their children in the experimental group received the Unified Protocol (UP) program online at 20 sessions twice a week. For the evaluation of emotion perception, we used the Test of Emotion Comprehension (TEC) which had high internal consistency. For statistical analyses, descriptive statistics and repeated measures ANOVA were used.

Mean score of emotion comprehension test at the mental and reflective levels and its overall score were significantly different between pretest and post-test and between pretest and follow-up phases in both group. The difference in the external level of emotion perception was not significant among three phases in any groups.

The UP program can positively affect the emotion perception in children with CI, especially in more difficult levels (mental and reflective), and its effects remain stable three months after the intervention.

Dichotic listening has been defined as the simultaneous stimulation of both ears and has been used to evaluate a listener’s binaural integration/separation ability. Dichotic tests are available in various languages and use varied stimuli. The study aimed to evaluate the differential performance of Tamil-speaking young adults in two tests of dichotic perception namely Dichotic Consonant Vowel (DCV) test and Dichotic Digit Test in Tamil (DDT-T).

Sixty adults with normal hearing aged 18 to 35 years were the participants of the study. All the young adults were native speakers of the Tamil language without significant auditory history. DCV and DDT-T were administered in randomized order at 50 dB SL (re: SRT) in free recall condition. The participants were instructed to respond orally and the responses were noted.

Better performance was observed in dichotic digit compared to DCV test for all participants. This was attributed to the higher number of cues available in DDT-T. Further, error analyses of participants’ responses revealed that voicing errors were higher with the highest errors in the identification of unvoiced consonant /ta/ in both ears. The reason for this could be the lack of contextual cues in DCV test for Tamil-speaking individuals to interpret the voicing feature of a consonant.

It can be concluded that DDT-T was more useful in assessing binaural integration ability of native Tamil speakers compared to DCV. It is recommended to be used in the behavioral test battery for evaluating auditory processing disorder in native Tamil speakers.

Musical training has been hypothesised to result in enhanced Speech Perception in Noise (SPIN) abilities, but prolonged exposure to music also increases the risk for Music-Induced Hearing Loss (MIHL). The Signal-to-Noise Ratios (SNR) and the Extended High Frequency (EHF) thresholds between formally trained musicians and nonmusicians were compared to determine the effect of musical training on musicians’ SPIN and hearing abilities.

This cross-sectional study included 40 musicians and 39 non-musicians 18–30 years, with mean age (SD) 22.43(2.71) years. EHF audiometry and the Digits-in-Noise (DIN) test were conducted via a smartphone.

Differences found between the two groups regarding the DIN test and EHF thresholds were statistically insignificant. Musicians displayed early signs of MIHL as the musicians reported significantly more (p=0.004) instances of tinnitus than non-musicians. A statistically significant correlation was found only for the non-musician group between the 12.5 kHz threshold left and the SNR obtained in the diotic listening condition (rs=-0.465; p=0.003).

The results suggested that musicians did not display a significant advantage for SPIN and did not appear to have significantly poorer EHF hearing sensitivity. However, slight trends were noticeable in the musicians which gravitated more towards studies that found enhanced SPIN abilities and elevated EHF thresholds in the musician population. In the future, it may be useful to include additional speech tests (open-set) alongside the DIN test (closed-set). The present study suggests that EHF audiometry may be used for the early detection of MIHL.

Superior semicircular canal dehiscence (SSCD) is a rare bone defect in the petrous part of the temporal bone. In this syndrome, a third window is created between the middle cranial fossa and the bony labyrinth of the inner ear which can lead to stimulation of the vestibular system by sound. Patients usually have symptoms such as vertigo, imbalance, autophony, pulsatile tinnitus, and aural fullness. The clinical symptoms of this disease vary from person to person.

The Case: 

This study reports a case of a rare bilateral SSCD in a 39-year-old woman with imbalance and autophony problems. The audiological findings showed a bilateral mild conductive hearing loss at low frequencies with symptoms of vertigo and torsional nystagmus. The SSCD was diagnosed by computed tomography. Then, the patient underwent bone repair surgery. Auditory and balance tests were performed again after the surgery to evaluate the extent of recovery.

The SSCD can be diagnosed by using the mentioned test battery. By choosing the appropriate treatment methods and following up of the outcomes, most of the problems of patients with SSCD can be solved.