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Objective: Tinnitus is one of the reported complaints in individuals with Auditory Neuropathy Spectrum Disorder (ANSD). The study highlights the prevalence of tinnitus and its characteristics in individuals with ANSD. Study design: The study consisted of 95 patients with tinnitus out of 149 individuals with ANSD. The overall prevalence, laterality and gender effect was studied in these 95 patients. The study also reports on the subjective nature of tinnitus in 23 subjects and its relationship with the confi guration of the audiogram. Results: The prevalence of tinnitus was found to be around 67%, mostly bilateral (89.5%) and seen more often in females (70.52%). The subjective pitch was low-pitched in individuals with low frequency hearing loss and the perceived pitch was high with a fl at confi guration of loss. Conclusion: Our results show prevalence of tinnitus is more than 50% in individuals with ANSD and the tinnitus matched with the individual ' s frequency of maximal hearing loss.

The study aimed at understanding the psychoacoustic characteristics of tinnitus in individuals with auditory neuropathy spectrum disorder (ANSD). It attempts to assess the pitch and intensity of loudness of tinnitus matched by individuals with ANSD. Fifty individuals who were diagnosed as having auditory neuropathy spectrum disorder were included in the study. Tinnitus evaluation was carried out where the individuals matched the frequency and intensity of loudness of the tinnitus. The results of the study shows that pitch matched by majority of patients with ANSD is predominantly low pitched (<1000 Hz). The frequency of tinnitus matched by the patients with ANSD also correlated with the degree of maximal hearing loss. The intensity of loudness of the tinnitus was around 10-15 dB higher than their threshold in majority of the patients considered in the study. There was a weak negative correlation for the matched frequency and intensity of loudness. The results of the study suggest that majority of individuals with low frequency hearing loss had low pitched tinnitus. Thus, there could be discordant damage between outer and inner hair cells, abnormal firing of auditory nerve in individuals with ANSD which can lead to tinnitus. Thus, it can help to understand the physiology of tinnitus in individuals with ANSD.

Auditory neuropathy spectrum disorder (ANSD) describes a condition in which a patient's otoacoustic emissions (OAE) are (or were at one time) present and auditory brainstem responses (ABR) are abnormal or absent. ANSD is also diagnosed based on the presence of cochlear microphonics and abnormal or absent ABRs with or without abnormalities of OAE. We noted the changes in audiological characteristics over time with respect to pure tone thresholds, OAEs and Speech Identification Scores (SIS) in seven individuals with ANSD. The results indicated that all the individuals with ANSD had decreased SIS over time, whereas there was subsequent reduction in pure tone thresholds only in nine out of fourteen ears. There was absence of OAEs for two individuals in both ears during the follow-up evaluations. There was no regular pattern of changes in pure tone thresholds or SIS across all individuals. This indicates that there may be gradual worsening of hearing abilities in individuals with ANSD. Thus, regular follow-up and monitoring of audiological changes are necessary for individuals with ANSD. Also, longitudinal studies need to be done to further add evidence to the audiological changes over time in individuals with ANSD.

The results of the study show that there are gender differences in audiological findings and hearing aid benefits in individuals with ANSD. However, well-controlled prospective studies are essential to confirm the results obtained and to identify the possible mechanisms underlying the gender differences.

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Background:The auditory brainstem response (ABR) is usually abnormal in individuals with auditory neuropathy spectrum disorder (ANSD). However, in some such individuals the ABR is preserved at low repetition rates. This study attempts to understand the speech perception abilities of ANSD individuals who have preserved temporal synchronicity.Material and methods: There were 149 individuals with ANSD in the study. They were classified into two groups based on preserved or absent ABR. Speech identification scores (SISs) in these individuals in quiet and in the presence of noise were compared.Results: At low repetition rates some 12.5% of subjects had preserved ABR with low amplitude wave V. Of these, 81% had an SIS of more than 50% in quiet. However, in patients with absent ABR, only 27% of individuals had an SIS of more than 50%. For subjects who had preserved ABR the mean SIS was 73.1% in quiet and 36.5% in noise compared to 35.9% in quiet and 20.2% in noise for individuals who had absent ABR. Conclusions:One in eight of the patients with ANSD had preserved ABR. Speech understanding was also better in quiet and in the presence of noise in individuals with preserved ABR. We conclude that speech reception abilities depend upon neural synchronicity at the level of the auditory nerve.