Auditory Neuropathy Spectrum Disorder in Individuals with Sickle Cell Anemia: Case Study.

The present study attempted to understand the association between Auditory neuropathy spectrum disorder (ANSD) and Sickle cell anemia (SCA) and to recognize possible causative factors for the presence of ANSD in SCA individuals. Two cases, 24 years male and 17years female with a laboratory-confirmed diagnosis of Sickle cell anemia underwent detailed audiological evaluation i.e., pure tone audiometry, speech audiometry, immittance audiometry, otoacoustic emission, and auditory brainstem responses. Audiological evaluation revealed a bilateral moderate low-frequency sensorineural hearing loss in male and bilateral moderately severe sensorineural Hearing loss in female case with elevated Speech Recognition Threshold and poor Speech Identification Scores. 'A' type tympanogram with the absence of Acoustic reflexes and the presence of Otoacoustic emission with no distinct and reproducible peak V in Auditory Brainstem Response (ABR) at 90 dBnHL with the presence of ringing cochlear microphonics on polarity reversal collectively indicating bilateral ANSD in both cases. ANSD and SCA are reported to have a genetic basis of etiology. There might be possibilities that one genetic condition may be common in manifesting both conditions or one genetic condition can cause the presence of another genetic condition or can exaggerate the evolution of another genetic condition. Also, abnormal ABR findings indicate the possibility of neuropathological involvement in isolation or in combination with genetic abnormalities that need detailed investigation to understand non-genetic causative factors. Thus, paved the path for further research in this line and might provide better rehabilitative options.

Influence of BPPV and Meniere's Disease on Cognitive Abilities: A Questionnaire-Based Study.

The vestibular system connects the inner ear to the midbrain and subcortical structures and can affect cognition. Patients with vertigo often experience cognitive symptoms such as attention deficits, memory problems, and spatial perception difficulties. This study aimed to explore the cognitive impairments associated with Benign paroxysmal positional vertigo (BPPV) and Meniere's Disease (MD). A non-experimental group comparison design was used with 107 participants divided into three groups: Group I (clinically normal), Group II (BPPV), and Group III (MD). Participants completed a questionnaire with 10 cognition-related questions, and their responses were scored. The data were found to be non-normally distributed. The analysis revealed a significant difference in scores between Group I and both Group II and Group III. Chi-square tests showed that the responses to cognition-related questions varied among the groups, with Group II exhibiting more cognitive problems. Associated conditions like hypertension, diabetes, and hearing loss did not significantly influence the responses within each group. This study suggests a significant relationship between cognitive problems and patients with BPPV and MD. However, there was no association found between the cognitive problems experienced in BPPV and MD patients. These findings align with previous research indicating that vestibular disorders can lead to deficits in spatial memory, attention, and other cognitive functions. By understanding the link between cognition and vestibular disorders, we can improve diagnosis and rehabilitation services to enhance the quality of life for these patients.

Auditory Processing in Children with Specific Language Impairment: A FFR Based Study.

Specific language impairment (SLI) is diagnosed when a child has difficulty in producing or understanding spoken language for no apparent reason. The study attempted to assess the sub-cortical encoding in children with SLI using speech-evoked auditory brainstem response (ABR). The objective of the study was to compare the amplitude and latency of the frequency following response (FFR) parameters between the children with SLI and typically developing children. The frequency following response was recorded using/da/stimuli from ten ears of children diagnosed with SLI. The amplitude and the latencies of the different peaks of FFR in children with SLI were compared with those of typically developing children. The results of the study showed that the latencies of wave C and D were significantly prolonged in children with SLI compared to typically developing children. The waveforms obtained from the typically developing (TD) children were clearer and easily identifiable, with larger negativity observed in the troughs. The waveform morphology was poorer in children with SLI with shallower peaks. Thus, it can be concluded that speech evoked ABR gives an insight into the auditory processing ability of children with SLI. It indicates that signal processing in the auditory pathway of children with SLI is temporally distorted and which might affect the development of language.

Oral and Verbal Praxis in Impaired Language Learners.

In the context of language descriptions, the terms oral and verbal praxis refer to volitional movements for performing oral gestures and movements for speech. These movements involve programming articulators and rapid sequences of muscle firings that are required for speech sound productions. A growing body of research has highlighted the links between oral motor kinematics and language production skills in both typically developing (TD) children and children with developmental language disorders, including Specific Language Impairment (SLI). Yet, there have been limited attempts to assess the link between non-linguistic and linguistic development. In the present study, we investigated oral and verbal praxis behaviors in children with SLI. Fifteen children with SLI formed a clinical group and 15 children with typical development who were matched to the clinical group for chronological age, gender, and socio-economic status formed the TD group. We assessed participants in both groups for their language abilities with age-appropriate standardized language tests. To investigate oral and verbal praxis behaviors, we administered the Assessment Protocol for Oral Motor, Oral Praxis and Verbal Praxis Skills to the two groups. We used the non-parametric Mann-Whitney U test to compare the two groups with respect to oral and verbal praxis measures; and we found a significant difference between isolated and sequential movements in the oral praxis section in two age subgroups of these groups (p ≤ .05). Spearman's correlations revealed a strong correlation between core language scores and sequential movements in the younger children with SLI and in TD children. These results showed co-morbidity between SLI and poor oral motor skills, suggesting that SLI is not just a language disorder, but a group of co-morbid conditions that include oral motor and verbal praxis difficulties.

Effect of advancing age on inter-frequency amplitude ratio of ocular vestibular evoked myogenic potentials.

OBJECTIVE: The inter-frequency amplitude ratio (IFAR) is the ratio of the amplitude of 1000-Hz tone-burst evoked ocular vestibular evoked myogenic potential (oVEMP) to the 500 Hz tone-burst evoked oVEMP. Since IFAR is an amplitude-based parameter, and the amplitudes of oVEMP for different frequencies are differentially affected by ageing, IFAR could potentially be affected by the ageing process. Therefore, we aimed to examine the effects of ageing on the IFAR of oVEMPs. DESIGN: Multiple static groups comparison. STUDY SAMPLE: We recorded oVEMPs for 500 Hz and 1000 Hz tone-bursts from 270 healthy individuals, each included in one of the six age groups. RESULTS: The IFAR was significantly larger in the ≥60 years age group than the age groups up to 49 years. Furthermore, the IFAR in the 50-59 years age group was significantly larger than all the other age groups up to 39 years. There was a significant positive correlation between age and IFARs (p < 0.01). CONCLUSIONS: IFAR, a sensitive tool in the test battery for the diagnosis of Meniere's disease, is affected even in healthy individuals due to ageing; hence its cautious interpretation is recommended when evaluating adults >50 years of age who are suspected of having Meniere's disease.

Wideband absorbance tympanometry: a novel method in identifying otosclerosis.

PURPOSE: The purpose of the study was to know whether the wideband absorbance measurements can be a useful tool to identify ears with otosclerosis. The present study analyzed WBA measurements and highlighted its effectiveness in identifying ears with otosclerosis and differentiating from healthy normal ears. METHODS: The study included 42 ears with otosclerosis which were compared with an equal sample size of healthy normal ears. WBA across frequencies and wideband average absorbance (375-2000 Hz) at the peak and ambient pressure, and resonance frequency were measured and analyzed. RESULTS: Results showed that WBA levels increased with an increase in frequencies up to 2000 Hz and decreased thereafter, both in the otosclerosis and healthy normal ears. The mean WBA in the otosclerosis group was significantly lower in the 250-2000 Hz frequency range than in the healthy normal ear group. The WBA values at ambient pressure reduced significantly up to 500 Hz for the healthy normal ear group and 1500 Hz for otosclerosis group, compared with peak pressure. Further, the analysis of wideband average absorbance at ambient pressure showed reduced absorbance (0.35) and higher resonance frequency (1350.33 Hz) in the otosclerosis group compared with the healthy normal ear group (0.60 and 930.14 Hz, respectively). ROC analysis indicated that WBA is suitable for identifying otosclerotic ears and also in differentiating from healthy normal ears based on WBA values from 250 to 1500 Hz. High diagnostic values of WBA (> 90% sensitivity and specificity) were observed at a frequency of 1000 Hz. CONCLUSIONS: The inclusion of WBA into clinical routine test procedures could be a useful tool for detecting otosclerosis. Further research is required to validate its clinical use in combination with other middle ear measures.

Wideband absorbance pattern in adults with otosclerosis and ossicular chain discontinuity.

OBJECTIVES: Evidence from previous literature had shown that the use of a single frequency probe tone is not sensitive enough to detect middle ear pathologies, especially related to the ossicles, which hinders accurate diagnosis. The goal of the present study was to compare the outcome of wideband absorbance (WBA) tympanometry and to determine the difference in WBA pattern in adults with otosclerosis and ossicular chain discontinuity. MATERIALS AND METHODS: Estimated adult cases of otosclerosis (10 ears) and ossicular chain discontinuity (06 ears) along with healthy individuals (10 ears) in the age range of 24 to 48 years (mean age: 38.6 years) were considered for the study. WBA was measured at peak and ambient pressure along with resonance frequency and compared with the data obtained from the healthy individuals to determine the WBA pattern. RESULTS: Data analysis revealed a distinct WBA pattern showing high absorbance at 750 Hz for ossicular chain discontinuity compared to healthy individuals, whereas the otosclerosis group showed reduced absorbance (p < 0.05) at low frequencies (250 Hz to 1500 Hz). WBA measured at the peak and ambient pressure did not elicit any significant difference across the frequencies. Also, the average WBA tympanogram measured between 375 Hz and 2000 Hz showed a significant difference in ambient pressure only in the otosclerosis group. In comparison to healthy individuals (901 Hz), ossicular chain discontinuity showed a significant reduction in resonance frequency (674 Hz), whereas in cases with otosclerosis had higher resonance frequency (1445 Hz). CONCLUSIONS AND SIGNIFICANCE: The present study showed different WBA patterns between the groups and the absorbance values were significantly different at the low frequencies. This suggests that WBA has the potential to differentiate ossicles related pathologies from normal and also between the ear with otosclerosis and ossicular chain discontinuity.

Relationship between Speech Perception in Noise and Phonemic Restoration of Speech in Noise in Individuals with Normal Hearing.

BACKGROUND AND OBJECTIVES: Top-down restoration of distorted speech, tapped as phonemic restoration of speech in noise, maybe a useful tool to understand robustness of perception in adverse listening situations. However, the relationship between phonemic restoration and speech perception in noise is not empirically clear. SUBJECTS AND METHODS: 20 adults (40-55 years) with normal audiometric findings were part of the study. Sentence perception in noise performance was studied with various signal-to-noise ratios (SNRs) to estimate the SNR with 50% score. Performance was also measured for sentences interrupted with silence and for those interrupted by speech noise at -10, -5, 0, and 5 dB SNRs. The performance score in the noise interruption condition was subtracted by quiet interruption condition to determine the phonemic restoration magnitude. RESULTS: Fairly robust improvements in speech intelligibility was found when the sentences were interrupted with speech noise instead of silence. Improvement with increasing noise levels was non-monotonic and reached a maximum at -10 dB SNR. Significant correlation between speech perception in noise performance and phonemic restoration of sentences interrupted with -10 dB SNR speech noise was found. CONCLUSIONS: It is possible that perception of speech in noise is associated with top-down processing of speech, tapped as phonemic restoration of interrupted speech. More research with a larger sample size is indicated since the restoration is affected by the type of speech material and noise used, age, working memory, and linguistic proficiency, and has a large individual variability.

Optimum Response Filter Setting for Air Conduction-Induced Ocular Vestibular Evoked Myogenic Potential.

BACKGROUND: A wide range of normative values of amplitude and latencies can be noticed in the publications on ocular vestibular evoked myogenic potential (oVEMP), possibly because of the inconsistent use of various stimulus and acquisition-related parameters such as response filter, gaze angle, onset polarity of stimulus, etc. One major nonuniform parameter across studies is the response filter. Several band-pass response filters such as 0.5-500, 1-1000, 5-500, 5-800, 10-750, 20-2000, 100-3000, and 200-1000 Hz have been used across published studies, and a wide range of normative values can be noticed. However, there is paucity of literature evidence to show that variations in response filters could cause alterations in oVEMP response. PURPOSE: This study aimed to investigate the effects of changes in response filter setting on oVEMP. RESEARCH DESIGN: Normative study using repeated measures research design. STUDY SAMPLE: Young adults in the age range of 18-35 years (N = 150) and older adults in the age range of 60-70 years (N = 10). INTERVENTION: Contralateral air conduction oVEMP. DATA COLLECTION AND ANALYSIS: Contralateral air conduction oVEMP was obtained from only one ear of all participants. Low-pass filters (LPFs) of 500, 700, 1000, 1500, 2000, and 3000 Hz and high-pass filters (HPFs) of 0.1, 1, 10, and 30 Hz were used in all possible combinations of one LPF and one HPF to create band-pass filters. Latencies, peak-to-peak amplitude, and signal-to-noise ratio (SNR) were obtained for each response and comparison was made between various band-pass filters. RESULTS: In young adults, there was a significant reduction in n1 and p1 latencies with increasing HPF and LPF (p < 0.01) and a significant reduction in peak-to-peak amplitude with increasing HPF (p < 0.008). The peak-to-peak amplitude was significantly not affected by changes in LPF (p > 0.05). In older adults, the response rate was better for 0.1- to 1000-Hz than 1- to 1000-Hz band-pass filters. CONCLUSIONS: The optimum band-pass filter is 0.1-1000 Hz for recording oVEMP as it produces the largest amplitude oVEMP without compromising on SNR and causes improved response rate in older adults compared with 1- to 1000-Hz filters. Therefore, clinical recording of oVEMP should use 0.1-1000 Hz for obtaining large amplitude potentials and improving the chances of response detection in clinical population.

Inter-frequency amplitude ratio of oVEMP for differentiating Meniere's disease from BPPV: clinical validation using a double-blind approach.

OBJECTIVE: The study aimed at examining the usefulness of inter-frequency amplitude ratio (IFAR) of ocular vestibular evoked myogenic potential (oVEMP) in identifying Meniere's disease (MD) and differentiating it from benign paroxysmal positional vertigo (BPPV). DESIGN: A case-control design was used with a double blind approach. Phase 1 included 70 healthy individuals and 36 individuals each with MD and BPPV and Phase 2 included 20 individuals each with MD and BPPV. The age range of the participants in both phases was 15-50 years. All participants underwent oVEMP testing using 500 and 1000 Hz tone bursts and IFAR was obtained. RESULTS: The results in phase 1 revealed significantly higher IFARs in Meniere's disease than BPPV and healthy individuals (p < 0.001). An optimum criterion point of IFAR ≥1.11 for diagnosing MD was found which yielded 80% sensitivity and 98% specificity. The results in phase 2 demonstrated 85% correct identification of MD and 95% correct rejection of BPPV as non-MD. CONCLUSIONS: IFAR of oVEMP appears highly sensitive and specific parameter for identifying MD and a clinically valid tool for differentiating MD from BPPV.

Effectiveness of Low Cut Modified Amplification using Receiver in the Canal Hearing Aid in Individuals with Auditory Neuropathy Spectrum Disorder

Abstract Introduction The studies on hearing aid benefit in individuals with auditory neuropathy spectrum disorder (ANSD) shows limited benefit. Low cut modified amplification is found to be effective in few individuals with ANSD. With advancement in technology, receiver in the canal (RIC) hearing aids have proven to be more effective than traditional behind the ear (BTE) hearing aids. Objective Thus, the present study attempts to determine the effectiveness of low cut modified amplification using RIC and BTE. Method Twenty participants with ANSD were fitted with BTE and RIC using traditional and low cut modified amplification. We divided them into good and poor performers based on unaided speech identification scores (SIS). We then compared aided SIS and aided benefit across conditions in good and poor performers with ANSD across both conditions using BTE and RIC. Results The results of the study showed that the aided performance improved with low cut modified amplification in both BTE and RIC hearing aids. The improvement noticed with low-cut modified fitting with RIC was significant in more than BTE, especially in good performers with ANSD. Conclusion The improved clarity and naturalness of sound with RIC may have led to better aided scores and better acceptance of the hearing aid. Thus, low-cut modified amplification, preferably with RIC, needs to be attempted in fitting individuals with ANSD, especially in those with good unaided SIS in quiet.

Effectiveness of Low Cut Modified Amplification using Receiver in the Canal Hearing Aid in Individuals with Auditory Neuropathy Spectrum Disorder.

Introduction The studies on hearing aid benefit in individuals with auditory neuropathy spectrum disorder (ANSD) shows limited benefit. Low cut modified amplification is found to be effective in few individuals with ANSD. With advancement in technology, receiver in the canal (RIC) hearing aids have proven to be more effective than traditional behind the ear (BTE) hearing aids. Objective Thus, the present study attempts to determine the effectiveness of low cut modified amplification using RIC and BTE. Method Twenty participants with ANSD were fitted with BTE and RIC using traditional and low cut modified amplification. We divided them into good and poor performers based on unaided speech identification scores (SIS). We then compared aided SIS and aided benefit across conditions in good and poor performers with ANSD across both conditions using BTE and RIC. Results The results of the study showed that the aided performance improved with low cut modified amplification in both BTE and RIC hearing aids. The improvement noticed with low-cut modified fitting with RIC was significant in more than BTE, especially in good performers with ANSD. Conclusion The improved clarity and naturalness of sound with RIC may have led to better aided scores and better acceptance of the hearing aid. Thus, low-cut modified amplification, preferably with RIC, needs to be attempted in fitting individuals with ANSD, especially in those with good unaided SIS in quiet.

Effectiveness of low-cut modified amplification strategy and channel-free hearing aid in individuals with auditory neuropathy spectrum disorder.

OBJECTIVE: The present study attempted to compare the aided benefit using low-cut modified amplification and channel-free hearing aids in individuals with auditory neuropathy spectrum disorder (ANSD). It was also attempted to determine these effects in good and poor performers with ANSD. DESIGN: Cross-sectional within group pretest, post-test design. STUDY SAMPLE: Twenty-five individuals with acquired ANSD were selected for the study. The study sample included 11 males and 14 females between the age ranges of 17-40 years (mean age of 24.6 years). RESULTS: The results of the repeated measures analysis of variance (ANOVA) showed that aided benefit was significantly higher with the channel-free hearing aid. Mixed ANOVA results showed that the improvement was more in good performers than poor performers with ANSD. Multiple regression analyses showed that speech identification scores are a strong predictor of aided benefit. CONCLUSIONS: The results of the present study suggest that channel-free hearing aids and low-cut modified amplification can be used as an efficient alternative technique during hearing aid fitting for individuals with ANSD. However, further evidence-based studies on a larger group are essential to validate the results.

Utility of the Frequency Tuning Measure of oVEMP in Differentiating Meniere's Disease from BPPV.

BACKGROUND: Utility of frequency tuning of ocular vestibular evoked myogenic potential (oVEMP) for evaluation of utricular function in individuals with Meniere's disease is a recent development. However, there is dearth of studies regarding its utility in differential diagnosis of Meniere's disease from other vestibular pathologies. PURPOSE: The present study aimed at investigating the feasibility of frequency tuning of oVEMP in discriminating Meniere's disease from benign paroxysmal positional vertigo (BPPV). RESEARCH DESIGN: Static group comparison. STUDY SAMPLE: oVEMPs were acquired from 36 individuals, each with unilateral Meniere's disease and unilateral BPPV. Thirty-six age- and gender-matched healthy individuals formed comparison group for each of the two clinical groups. INTERVENTION: Contralateral oVEMPs were recorded from both ears of all the participants. DATA COLLECTION AND ANALYSES: The responses pertaining to octave and mid-octave frequencies from 250 to 4000 Hz, one frequency presented at a time, were recorded from infra-orbital electrodes (noninverting placed 1 cm below the lower eyelid and inverting 2 cm below the inverting on the cheek) with forehead as ground. Starting intensity was 125 dB peSPL with subsequent reductions in 10-dB steps to arrive at threshold. The stimuli were delivered to the ear at a rate of 5.1 Hz. The frequency corresponding to the largest peak-to-peak amplitude, best threshold, and/or largest peak-to-peak amplitude at thresholds was considered as the tuning frequency. Proportions of ears with frequency tuning at a particular frequency were compared between the groups. RESULTS: The frequency tuning at 1000 Hz was found to exist in a significantly higher proportion of affected ears with Meniere's disease than the comparison group as well as ears with BPPV (p < 0.05). Using a criterion point of frequency tuning at 875 Hz, the sensitivity and specificity for identifying Meniere's disease was found to be 68% and 100%, respectively. CONCLUSION: The shift in frequency tuning is an efficient parameter for not only discriminating Meniere's disease from healthy individuals but also distinguishing it from BPPV. Therefore, frequency tuning is recommended as a test parameter of oVEMP for identification of Meniere's disease.

Frequency-Amplitude Ratio of Ocular Vestibular-Evoked Myogenic Potentials for Detecting Meniere's Disease: A Preliminary Investigation.

OBJECTIVE: Several parameters of ocular vestibular-evoked myogenic potential (oVEMP) have been used to identify Meniere's disease. Nonetheless frequency-amplitude ratio (FAR), which is the ratio of amplitude between two frequencies, is one among the parameters that has failed to attract researchers' attention despite proving its worth in diagnosis of Meniere's disease when used in conjunction with cervical VEMP. Thus, the present study aimed at investigating the utility of FAR of oVEMP in identifying Meniere's disease and finding out an optimum frequency pair for its diagnosis. DESIGN: Using a case-control design, oVEMPs were recorded for tone bursts of 500, 750, 1000, and 1500 Hz from 36 individuals with unilateral definite Meniere's disease in the age range of 15 to 50 years. For comparison purposes, oVEMP at the above frequencies were also obtained from an equal number of age- and gender-matched healthy individuals. The amplitudes of 750, 1000, 1500 Hz and tuned frequency, which was the frequency with the largest peak to peak amplitude among the above-mentioned frequencies, were divided by the amplitude of 500 Hz to obtain FARs for 750/500, 1000/500, 1500/500, and tuned frequency/500 frequency pairs. RESULTS: The results revealed significantly higher FAR in the Meniere's disease group than the healthy controls for all the frequency pairs (p < 0.05). The sensitivity of almost 90% and the specificity 100% was obtained for 1000/500 and 750/500, whereas the other frequency pairs produced a sensitivity of about 56% while still showing a specificity of 100%. CONCLUSIONS: High sensitivity and specificity, coupled with considerably lowered test duration when using only two frequencies, makes the use of FAR a more attractive prerogative, with 1000/500 as the frequency pair of choice.

Efficacy of ocular vestibular-evoked myogenic potential in identifying posterior semicircular canal benign paroxysmal positional vertigo.

OBJECTIVES: Benign paroxysmal positional vertigo (BPPV) is a unilateral peripheral vestibular pathology, mostly involving the semicircular canals and the otolith organs. Although equivocal findings exist on the utility of cervical vestibular-evoked myogenic potential in identifying BPPV-associated changes in saccule, ocular vestibular-evoked myogenic potential (oVEMP), which is primarily a utricular response, has sparingly been explored in this population. Hence, the present study aimed at examining oVEMP in individuals with BPPV and comparing them with healthy individuals to illustrate its efficacy in identifying BPPV-associated changes in the utricle. DESIGN: Using a case-control design, oVEMPs were elicited by 500 Hz tone bursts at 125 dB peak sound pressure level and recorded bilaterally from 30 individuals with unilateral posterior canal BPPV and 30 age- and gender-matched healthy controls. RESULTS: There were no inter- or intragroup differences in latency aspects (p > 0.05); however, amplitudes were significantly smaller in BPPV ears compared with the non-BPPV ears of individuals with BPPV as well as ears of healthy controls (p < 0.05). Exceptions to this were five participants with BPPV in whom the affected ears demonstrated larger response amplitude (augmentation) than the unaffected ears. Furthermore, there was significantly larger interaural amplitude ratio in individuals with BPPV compared with the healthy controls (p < 0.05). Interaural amplitude ratio produced the largest effect size among the oVEMP parameters for differentiating BPPV from healthy controls. CONCLUSIONS: Large asymmetry ratio of oVEMP, usually exceeding 26.8%, is the most potent characteristic of oVEMP in BPPV. Abnormal oVEMP results confirm utricular pathology in ears with BPPV, and therefore, oVEMP can be used as an objective tool with asymmetry ratio as the parameter of choice for the evaluation of utricular function in persons with posterior canal BPPV.

Rise/fall and plateau time optimization for cervical vestibular-evoked myogenic potential elicited by short tone bursts of 500 Hz.

OBJECTIVE: Literature on clinical utility of cervical vestibular-evoked myogenic potential (cVEMP) has been increasing rapidly, though not without inconsistencies in spite of involving similar populations. Close examination of methods across studies exposed the use of variable stimulus parameters, especially rise/fall time (R/FT) and plateau time (PT) as the possible reason. However the effect of variation in R/FT and PT on cVEMP response parameters has been largely uncharted. DESIGN: The study aimed at evaluating the impact of R/FT and PT on cVEMPs elicited by 500-Hz short tone-bursts (STBs) at 95 dB nHL using R/FT from 1 to 4 ms and PT from 0 to 3 ms. STUDY SAMPLE: 30 healthy individuals with normal audio-vestibular system. RESULTS: Significant prolongation of latencies with increasing R/FT and PT (p < 0.05) was noticed. The amplitude however varied significantly only for some R/FTs and PTs. R/FT of 2 ms, in combination with 1-ms PT, produced large amplitudes with lowest variability in amplitude and latency parameters. CONCLUSIONS: R/FT of 2 ms along with PT of 1 ms formed a good amalgamation and could be considered optimum for clinical recording of cVEMPs elicited by 500-Hz STBs, although slight deviances in these parameters might not impact the outcome significantly.

Effect of companding on speech recognition in quiet and noise for listeners with ANSD.

OBJECTIVE: The present study assesses the effect of companding on speech perception in quiet and noise for listeners with auditory neuropathy spectrum disorder (ANSD). DESIGN: Speech perception was assessed using speech reception threshold in noise (SRTn) for sentences and consonant identification in quiet and at different signal-to-noise ratios (15, 10, 5, and 0 dB SNR). STUDY SAMPLE: Ten ANSD listeners and normal-hearing listeners participated in the study. RESULTS: ANSD listeners required significantly higher SRTn when compared to the normal-hearing listeners. Companding reduced SRTn more significantly in listeners with ANSD, but for normal-hearing listeners there was only a marginal reduction. In the consonant identification task, ANSD listeners performed poorer than normal-hearing listeners in quiet and noise. Companding improved consonant identification in quiet and at 15 dB SNR for listeners with ANSD, whereas no improvement was observed in normal-hearing listeners. CONCLUSION: Results of the present study demonstrate that companding improved speech perception in quiet and noise for ANSD listeners. The amount of improvement is higher at higher SNRs. In normal-hearing listeners, companding showed marginal improvement in both quiet and noise. The findings are discussed for rehabilitation of ANSD listeners by hearing aids which incorporate the companding strategy.

Characterizing the frequency tuning properties of air-conduction ocular vestibular evoked myogenic potentials in healthy individuals.

OBJECTIVE: Inconsistencies regarding frequency tuning of ocular vestibular evoked myogenic potentials (oVEMP) prompted the present study to aim at characterizing frequency tuning of oVEMP in healthy individuals. DESIGN: Normative study. STUDY SAMPLE: The study was conducted to obtain oVEMP responses from 54 healthy individuals in age range of 18-30 years. The responses were acquired for tone-bursts at octave and mid-octave frequencies from 250 to 2000 Hz from the inferior oblique muscle using contralateral electrode placement. The frequencies were compared for amplitude and threshold. RESULTS: oVEMPs were present in 100% of individuals at or below the frequency of 1000 Hz. The responses had maximum amplitude and lowest thresholds at 500 Hz. There were at least two replicable peak-complexes namely n1-p1 and p1-n2. Both these complexes revealed tuning at 500 Hz. Comparison between the two peak-complexes revealed higher amplitudes and lower thresholds for p1-n2 complex. CONCLUSIONS: oVEMPs are tuned to 500 Hz for both peak-complexes, with p1-n2 being more robust. Future studies using the threshold of oVEMP may be better suited to use p1-n2 complex for this purpose, provided vestibular origin of the second complex is proved. Additionally, careful use of tuning property is recommended when evaluating pathological conditions.

Involvement of peripheral vestibular nerve in individuals with auditory neuropathy.

The vestibulocochlear nerve is a sensory nerve that serves the organs of hearing and equilibrium. Neuropathies of the nerve, particularly auditory neuropathy may be caused by primary demyelination or by axonal diseases. In disorders affecting the cochlear nerve, it is probable that the vestibular nerve is involved as well. There are isolated reports of the involvement of the inferior vestibular nerve (using vestibular-evoked myogenic potentials) in individuals with AN. However, there is a dearth of information on the involvement of the superior vestibular nerve and other functions such as optokinetic, saccade and vestibulo-occular reflex. A total of three subjects diagnosed as having auditory neuropathy, underwent an extensive vestibular assessment consisting of clinical tests of stability (Romberg, Fukuda stepping test), administration of dizziness questionnaire developed by Maryland hearing and balance centre, cervical vestibular-evoked myogenic potentials and a standard electronystagmography test battery. In the present study, the entire subject population assessed showed hypofunctional caloric responses and absent VEMPs. Two out of the three subjects were asymptomatic of vestibular dysfunction. On the clinical tests of stability, two subjects showed deviations to the right, while one subject performed normally. Thus, the present study indicates a possible involvement of peripheral vestibular nerve involvement in individuals with auditory neuropathy.