Research Hub is designed to share the research activities conducted by Dr Hashir Aazh and his collaborators on tinnitus, hyperacusis and misophonia. Research Hub also shares relevant research projects from other institutions. The aim is to enhance scientific collaboration and encourage public engagement in research.

Take part in our research on hyperacusis and misophonia

January 2022

Our PhD student from Istanbul, Turkey, is evaluating modern psychometric instruments for assessment of misophonia and hyperacusis at University of Surrey, Guildford.

Can an online course help parents with anxiety raise confident children?

January 2022

The Parenting with Anxiety project is testing a new online course to help parents who experience anxiety, and their children, so they can become more confident together.

Hearing Tinnitus in Dreams

January 2022

In their new paper published in the Journal of the American Academy of Audiology, Dr Hashir Aazh and his collaborators studied the incidence of the perception of tinnitus in dreams among patients seeking help for tinnitus and/or hyperacusis.

Influence of ear canal occlusion and static pressure difference on bone conduction thresholds: implications for mechanisms of bone conduction

December 2021

The effect of air pressure change on bone conduction (BC) hearing thresholds in the occluded ear was investigated. The pump manometer system of an impedance bridge was used to change the air pressure in the ear canal of twenty-two normally hearing subjects. BC thresholds were measured with: (1) open ear; (2) the ear canal occluded with a probe tube and application of 0 daPa air pressure; and (3) the ear canal occluded with a probe tube and application of 350 daPa air pressure. Thresholds were lower in condition 2 than in condition 1, the difference decreasing from 27 dB at 2500 Hz to 4.5 dB at 2000 Hz. Thresholds were higher in condition 3 than in condition 2. The results are interpreted in terms of changes in the relative contribution of the three routes of transmission for BC sound produced by occlusion and by a static pressure difference.

Dead regions in the cochlea at 4 kHz in elderly adults: relation to absolute threshold, steepness of audiogram, and pure-tone average

December 2021

The aims of this study were (1) to investigate the prevalence of dead regions (DRs) at 4 kHz in elderly people with hearing loss and (2) to determine the extent to which the presence/absence of a DR can be predicted from the absolute threshold, the slope of the audiogram, or the pure-tone average (PTA) hearing loss at 0.5, 1, and 2 kHz. DRs were assessed for 98 ears with absolute thresholds between 60 and 85 dB HL at 4 kHz using the threshold equalizing noise test. Thirty-six ears had a DR at 4 kHz. There was no statistically significant difference in the slope of the audiogram or PTA between ears with and without DRs. However, the mean absolute threshold at 4 kHz was significantly higher for the group with DRs than for the group without DRs. The prevalence of DRs exceeded 50% for hearing losses greater than 70 dB.

Real ear measurement methods for open fit hearing aids: Modified pressure concurrent equalization (MPCE) versus modified pressure stored equalization (MPSE)

December 2021

Objective: The aim of this study was to assess differences between real ear insertion gains (REIG) measured with the modified pressure concurrent equalization (MPCE) and modified pressure stored equalization (MPSE) methods for open fittings in a typical audiology patient population. Design: REIGs were compared for the two methods using a warble tone sweep at 65 dB SPL. The differences between the two methods at 0.25, 0.5, 1, 2, 3, 4 and 6 kHz were recorded. Study sample: Eighty-three ears of a consecutive sample of 48 candidates for open-fit hearing aids were included. Results: The mean difference between MPSE and MPCE REIGs was less than 1 dB at all frequencies. Analysis of variance showed that the main effect of method was not significant, and there was no significant interaction between method and frequency. Conclusions: The results for the MPSE and MPCE methods did not differ significantly for the patients with mild-to-moderate hearing losses tested here, for whom REIGs were generally less than 20 dB. Further research is needed to identify the REIG values at which the differences between MPCE and MPSE methods become clinically significant.

The Accuracy of Matching Target Insertion Gains With Open-Fit Hearing Aids

December 2021


To assess the accuracy with which target insertion gains were matched for a single type of open-fit hearing aid, both on initial fitting and after adjustment.


The hearing aids were fitted using the first-fit setting in the programming software and the target formula was selected as NAL–NL1. The difference between the real ear insertion gain (REIG) and the NAL–NL1 target REIG was recorded. The initial fitting was considered acceptable if the difference was less than 10 dB at all frequencies. If an initial fitting was not acceptable, the frequency-gain response was modified. The difference between the final REIG and the NAL–NL1 target REIG was recorded as final target mismatch.


Of the 51 initial fittings, 36 (71%) failed to achieve a match within ±10 dB of the NAL–NL1 insertion gain target at 1 or more frequencies between 0.25 and 4 kHz. After the authors adjusted the frequency-gain response of the hearing aids, only 9 fittings (18%) failed to achieve a match.


These outcomes suggest that target insertion gains for the open-fit hearing aids used here are rarely achieved with a first fitting but can usually be achieved through adjustments based on REIG measurements.

Hearing-aid use and its determinants in the UK National Health Service: A cross-sectional study at the Royal Surrey County Hospital

December 2021

Objectives: The aim of this study was to investigate the rate of and factors contributing to non-adherence to hearing-aid use in the UK National Health Service. Design: A cross-sectional postal questionnaire survey. Study sample: A questionnaire, including the International Outcome Inventory for Hearing Aids, was sent to all patients fitted with hearing aids at the Royal Surrey County Hospital between 2011 and 2012 (N = 1874). A total of 1023 questionnaires were completed and returned (response rate of 55%). Results: A total of 29% of responders did not use their hearing aids on a regular basis (i.e. used them less than four hours per day). Non-regular use was more prevalent in new (40%) than in existing patients (11%). Factors that reduced the risk of non-regular use included bilateral versus unilateral amplification, and moderate or severe hearing loss in the better ear. 16% of responders fitted with bilateral amplification used only one of their hearing aids. Conclusions: The level of non-regular use of hearing aids in NHS found in this study was comparable to those for other countries. Additional support might be needed for patients at a higher risk of non-regular use.

Feasibility of conducting a randomized controlled trial to evaluate the effect of motivational interviewing on hearing-aid use

December 2021

Objectives: The aim of this study was to evaluate the feasibility of conducting a randomized controlled trial (RCT) on the effect of motivational interviewing (MI) on hearing-aid use. Design: This was a pilot single-blind, randomized parallel-group study conducted in the UK. Study sample: Thirty-seven adult patients who reported using their hearing aid(s) less than four hours per day were randomized to MI combined with Standard Care (MISC) (n = 20), and Standard Care only (SC) (n = 17). Results: Of 220 patients invited, 37 were enrolled giving the recruitment rate of 17%. One participant withdrew giving the retention rate of 97%. It was feasible to combine MI with SC for facilitating hearing-aid use and deliver the intervention with high fidelity in an audiology setting. The measure on hearing-aid use (data logging) one month after interventions favoured the MISC group. Conclusions: This pilot study suggests that conducting an RCT on using MI for facilitating hearing-aid use in people who do not use their hearing aids is feasible, and that MI combined with SC may have more positive effects on hearing-aid use compared to SC only.

Audiological Rehabilitation for Facilitating Hearing Aid Use: A Review

December 2021

Purpose: This article reviews and critically analyzes the design of studies on the effect of audiological rehabilitation (AR) programs on hearing aid (HA) outcomes, in order to guide future research.

Research design: The design of this study was a narrative review. Studies were included in the review if they were randomized controlled trials that investigated the effects of AR on HA use and outcome between 2000 and 2016.

Results: Seven articles that met the inclusion criteria were included in the review. Most used educational rather than counseling approaches. Although educational AR programs seem to be useful in enhancing the use of communication strategies, there is limited evidence for their effect on HA use and self-perceived hearing handicap.

Conclusions: More research is needed in this field. Future studies should (1) investigate the efficacy of AR interventions based on counseling and empathetic listening as opposed to or in addition to educational interventions, (2) use stricter criteria to include only a subpopulation of patients who do not get on well with their HAs, (3) measure the amount of HA use via data-logging and self-report questionnaires, and (4) use a matching comparison intervention for patients in the control group.

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