Device and Fitting Protocol for a Transitional Intervention for Debilitating Hyperacusis.

PURPOSE: This report describes a hearing device and corresponding fitting protocol designed for use in a transitional intervention for debilitating loudness-based hyperacusis. METHOD: The intervention goal is to transition patients with hyperacusis from their typical counterproductive sound avoidance behaviors (i.e., sound attenuation and limited exposure to healthy low-level sounds) into beneficial sound therapy treatment that can expand their dynamic range to the point where they can tolerate everyday sounds and experience an improved quality of life. This requires a combination of counseling and sound therapy, the latter of which is provided via the hearing device technology, signal processing, and precision fitting approach described in this report. The device combines a miniature behind-the-ear sound processor and a custom earpiece designed to maximize the attenuation of external sounds. Output-limiting loudness suppression is used to restrict exposure to offending high-level sounds while unity gain amplification maximizes exposure to healthy and tolerable lower level sounds. The fitting process includes measurement of the real-ear unaided response, the real-ear measurement (REM) system noise floor, the real-ear occluded response, real-ear insertion gain, and the output limit. With these measurements, the device can achieve the prescribed unity gain needed to provide transparent access to comfortable sound levels. It also supports individualized configuration of the therapeutic noise from an on-board sound generator and adaptive output limiting based on treatment-induced increases in dynamic range. RESULTS AND CONCLUSION: The utility of this device and fitting protocol, in combination with structured counseling, is highlighted in the outcomes of a successful 6-month trial of the transitional intervention described in a companion report in this issue.

Counseling Protocol for a Transitional Intervention for Debilitating Hyperacusis.

INTRODUCTION: This clinical focus article describes a structured counseling protocol for use with protected sound management and therapeutic sound in a transitional intervention for debilitating hyperacusis. The counseling protocol and its associated visual aids are crafted as a teaching tool to educate affected individuals about hyperacusis and encourage their acceptance of a transitional intervention. DESCRIPTION OF COUNSELING COMPONENTS: The counseling protocol includes five components. First, the patient's audiometric results are reviewed with the patient, and the transitional intervention is introduced. An overview of peripheral auditory structures and central neural pathways and the concept of central gain are covered in the second and third components. Maladaptive hyper-gain processes within the auditory neural pathways, which underlie the hyperacusis condition, and associated connections with nonauditory processes responsible for negative reactions to hyperacusis are covered in the fourth component. Detrimental effects from misused hearing protection devices (HPDs) and the necessity to wean the patient from overuse of HPDs are also discussed. In the fifth component, the importance of therapeutic sound is introduced as a tool to downregulate hyper-gain activity within the auditory pathways; its implementation in uncontrolled and controlled sound environments is described. It is explained that, over the course of the transitional intervention, recalibration of the hyper-gain processes will be ongoing, leading to restoration of normal homeostasis within the auditory pathways. In turn, associated activation of reactive nonauditory processes, which contribute to hyperacusis-related distress, will be reduced or eliminated. As recalibration progresses, there will be less need for protected sound management and sound therapy. Sound tolerance will improve, hyperacusis will subside, and daily activities in typical healthy sound environments will again become routine. RESULTS AND CONCLUSION: The combination of counseling with protected sound management and therapeutic sound is highlighted in companion reports, including a summary of the outcomes of a successful trial of the transitional intervention.

Background and Rationale for a Transitional Intervention for Debilitating Hyperacusis.

PURPOSE: This report provides the experimental, clinical, theoretical, and historical background that motivated a patented transitional intervention and its implementation and evaluation in a field trial for mitigation of debilitating loudness-based hyperacusis (LH). BACKGROUND AND RATIONALE: Barriers for ameliorating LH, which is differentiated here from other forms of hyperacusis, are delineated, including counterproductive management and treatment strategies that may exacerbate the condition. Evidence for hyper-gain central auditory processes as the bases for LH and the associated LH-induced distress and stress responses are presented. This presentation is followed by an overview of prior efforts to use counseling and therapeutic sound as interventional tools for recalibrating the hyper-gain LH response. We also consider previous efforts to use output-limiting sound-protection devices in the management of LH. This historical background lays the foundation for our transitional intervention protocol and its implementation and evaluation in a field trial. CONCLUSIONS: The successful implementation and evaluation of a transitional intervention, which we document in the outcomes of a companion proof-of-concept field trial in this issue, build on our prior efforts and those of others to understand, manage, and treat hyperacusis. These efforts to overcome significant barriers and vexing long-standing challenges in the management and treatment of LH, as reviewed here, are the pillars of the transitional intervention and its primary components, namely, counseling combined with protective sound management and therapeutic sound, which we detail in separate reports in this issue.

Results of a 6-Month Field Trial of a Transitional Intervention for Debilitating Hyperacusis.

PURPOSE: We present results from a 6-month field trial of a transitional intervention for debilitating primary hyperacusis, including a combination of structured counseling; promotion of safe, comfortable, and healthy sound exposure; and therapeutic broadband sound from sound generators. This intervention is designed to overcome barriers to successful delivery of therapeutic sound as a tool to downregulate neural hyperactivity in the central auditory pathways (i.e., the maladaptive mechanism believed to account for primary hyperacusis) and, together with the counseling, reduce the associated negative emotional and physiological reactions to debilitating hyperacusis. METHOD: Twelve adults with normal or near-normal audiometric thresholds, complaints consistent with their pretreatment loudness discomfort levels ≤ 75 dB HL at multiple frequencies, and hearing questionnaire scores ≥ 24 completed the sound therapy-based intervention. The low-level broadband therapeutic sound was delivered by ear-level devices fitted bilaterally with either occluding earpieces and output-limiting loudness suppression (LS; to limit exposure to offensive sound levels) or open domes to maximize comfort and exposure to sound therapy. Thresholds for LS (primary outcome) were incrementally adjusted across six monthly visits based on treatment-driven change in loudness judgments for running speech in sound field. Secondary outcomes included categorical loudness judgments, speech understanding, and questionnaires to assess the hyperacusis problem, quality of life, and depression. An exit survey assessed satisfaction with and benefit from the intervention and the counseling, therapeutic sound, and LS components. RESULTS: The mean change in LS (34.8 dB) was highly significant (effect size = 2.045). Eleven of 12 participants achieved ≥ 16-dB change in LS, consistent with highly significant change in sound-based questionnaire scores. Exit surveys indicated satisfaction with and benefit from the intervention. CONCLUSION: The transitional intervention was successful in improving the hyperacusis conditions of 11 of 12 study participants while reducing their sound avoidance behaviors and reliance on sound protection.

Acoustic deprivation modulates central gain in human auditory brainstem and cortex.

Beyond reduced audibility, there is convincing evidence that the auditory system adapts according to the principles of homeostatic plasticity in response to a hearing loss. Such compensatory changes include modulation of central auditory gain mechanisms. Earplugging is a common experimental method that has been used to introduce a temporary, reversible hearing loss that induces changes consistent with central gain modulation. In the present study, young, normal-hearing adult participants wore a unilateral earplug for two weeks, during which we measured changes in the acoustic reflex threshold (ART), loudness perception, and cortically-evoked (40 Hz) auditory steady-state response (ASSR) to assess potential modulation in central gain with reduced peripheral input. The ART decreased on average by 8 to 10 dB during the treatment period, with modest increases in loudness perception after one week but not after two weeks of earplug use. Significant changes in both the magnitude and hemispheric laterality of source-localized cortical ASSR measures revealed asymmetrical changes in stimulus-driven cortical activity over time. The ART results following unilateral earplugging are consistent with the literature and suggest that homeostatic plasticity is evident in the brainstem. The novel findings from the cortical ASSR in the present study indicates that reduced peripheral input induces adaptive homeostatic plasticity reflected as both an increase in central gain in the auditory brainstem and reduced cortical activity ipsilateral to the deprived ear. Both the ART and the novel use of the 40-Hz ASSR provide sensitive measures of central gain modulation in the brainstem and cortex of young, normal hearing listeners, and thus may be useful in future studies with other clinical populations.

Contributions of Counseling and Sound Generator Use in Tinnitus Retraining Therapy: Treatment Response Dynamics Assessed in a Secondary Analysis of a Randomized Trial.

PURPOSE: Tinnitus retraining therapy (TRT) has been widely used for 30 years, but its efficacy and the component contributions from counseling and sound therapy remain controversial. The purpose of this secondary analysis from the Tinnitus Retraining Therapy Trial (TRTT) was to compare treatment response dynamics for TRT (counseling and conventional sound generators) with partial TRT (pTRT; counseling and placebo sound generators) and standard of care (SOC; a patient-centered counseling control). METHOD: The TRTT randomized 151 participants with primary tinnitus (no significant hearing or sound tolerance problems) to TRT, pTRT, or SOC, each of which encouraged use of enriched environmental sound. The primary outcome, mean change in Tinnitus Questionnaire score assessed at baseline and follow-up across 18 months, was normalized for a common baseline and fitted with an exponential model. Time constants were estimated to quantify and compare the treatment response dynamics, which were evaluated for statistical significance using bootstrap analyses. RESULTS: The change in response to TRT took less time to achieve than that for either pTRT or SOC, as demonstrated by time for normalized Tinnitus Questionnaire scores to decline to 63% and 99% of baseline TRT values: 1.2 months (95% CI [0.2, 1.9]) and 5.7 months (95% CI [0.9, 9.0]), respectively. Corresponding SOC values were 2.7 months (95% CI [1.5, 4.1]) and 12.4 months (95% CI [6.9, 19.0]), while those for pTRT were 2.2 months (95% CI [1.2, 3.4]) and 10.1 months (95% CI [5.7, 15.9]). The differences were significant for TRT versus SOC (p = .020), borderline significant for TRT versus pTRT (p = .057), but nonsignificant for pTRT versus SOC (p = .285). The magnitude of the asymptotic treatment response did not differ significantly among groups. CONCLUSION: Sound generator use in TRT increases treatment efficiency (beyond any advantage from enriched environmental sound) without affecting treatment efficacy (determined by counseling).

The Tinnitus Retraining Therapy Counseling Protocol as Implemented in the Tinnitus Retraining Therapy Trial.

Purpose This clinical focus article is a companion to the work of Erdman et al. (2019), in which we described the rationale, development, and implementation of the standard-of-care protocol used in the Tinnitus Retraining Therapy Trial (TRTT), a multicenter, placebo-controlled, randomized, definitive efficacy trial of tinnitus retraining therapy (TRT). We now describe the historical background, development, and standardized implementation and delivery of the TRT counseling protocol (tinnitus counseling [TC]) used in the TRTT. TC is conjectured to be the key component in the TRT protocol for initiating the habituation process that reduces the response to the tinnitus signal and, ultimately, reduces its impact. In the TRTT, participants assigned to receive TC achieved > 30% reduction in the impact of tinnitus. Method and Results The design and implementation of standardized treatments in multisite randomized controlled trials presents many challenges for investigators. Here, subsequent to presenting the background, rationale, and the TRT protocol model, we describe the development, refinement, and training/certification for standardized delivery of TC in the TRTT. The primary challenges encountered while distilling and streamlining TC for standardized delivery across multiple clinicians and their replacements at six participating military treatment centers in the TRTT are considered, and the resulting counseling protocol is detailed. Conclusions The standardized and streamlined TC used in the TRTT was successful for treating debilitating tinnitus among persons with functionally adequate unaided hearing sensitivity. The structured TC protocol described here appears to be the main determinant of the significant and sizable TRT treatment effects measured in the TRTT, thus bolstering the merits of this standardized counseling approach as one model for the clinical implementation of TRT for the treatment of primary tinnitus.

Treatment fidelity in the Tinnitus Retraining Therapy Trial.

BACKGROUND: Treatment fidelity, defined as ensuring that the recipient receives the intended intervention, is a critical component for accurate estimation of treatment efficacy. Ensuring fidelity and protocol adherence in behavioral trials requires careful planning during the design phase and implementation during the trial. The Tinnitus Retraining Therapy Trial (TRTT) randomized individuals with severe tinnitus to tinnitus retraining therapy (TRT, comprised of tinnitus-specific educational counseling (TC) and sound therapy (ST) using conventional sound generators (SGs)); Partial TRT (TC and placebo SGs); or standard of care (SOC), using a patient-centered care approach. Study audiologists administered both types of counseling in the TRTT, creating a challenge for managing protocol adherence. METHODS: We developed methods to enhance treatment fidelity including training, competency assessment, scripts, visual aids, and fidelity monitoring. Protocol monitors identified critical topics and content to be addressed for each type of counseling session, prepared corresponding scripts, and developed training aids and treatment-specific checklists covering those topics. Study audiologists' competency assessment required submission and review by the protocol monitors of an audiotape of one TC and one SOC counseling session. Treatment-specific aids included scripts, a 3-D model of the ear, handouts, and for TC, an illustrated flip-chart with talking points that followed the scripted content. During the trial, audiologists completed treatment-specific checklists during each counseling session, indicating topics covered/discussed and submitted audiotapes of counseling sessions. Protocol monitors reviewed audiotapes using corresponding treatment-specific checklists. Results for individual checklist items were tabulated and proportions calculated. RESULTS: Twenty-five audiologists were certified for TC and/or SOC counseling and 24 completed at least one counseling session. Adherence to each of 33 critical items on the TC checklist as assessed by the protocol monitor ranged from 70 to 100% across 37 counseling sessions (median 97%), with no difference between adherence for TRT (median, 97%) and partial TRT (median, 100%). Adherence to each of 44 critical items on the SOC checklist across 30 SOC counseling sessions ranged from 42 to 100% (median, 87.5%). CONCLUSION: The TRTT used multiple methods to address treatment fidelity. The close adherence to each treatment type was critical for evaluating the efficacy of the study interventions in this randomized trial. TRIAL REGISTRATION: clinicaltrials.gov NCT01177137 . Registered on 5 August 2010.

The Tinnitus Retraining Therapy Trial's Standard of Care Control Condition: Rationale and Description of a Patient-Centered Protocol.

Purpose The selection and design of control conditions are critical factors in minimizing the influence of unwanted variables in randomized controlled trials (RCTs). This article describes the rationale, design, and content of a standard of care control condition in a Phase III RCT of tinnitus retraining therapy. Method Existing tinnitus practices at military hospitals were identified and aligned with the American Speech-Language-Hearing Association's (2006) preferred practice patterns for tinnitus management and counseling and embedded in a patient-centered protocol to ensure uniformity and treatment fidelity. Results For those involved in the design of behavioral RCTs, the article identifies options and methods to consider in the selection and design of control conditions. Conclusion For those who provide tinnitus services, the standard of care protocol developed for the tinnitus retraining therapy trial constitutes a patient-centered approach to intervention that can be implemented clinically. Supplemental Material https://doi.org/10.23641/asha.9342503.

Effect of Tinnitus Retraining Therapy vs Standard of Care on Tinnitus-Related Quality of Life: A Randomized Clinical Trial.

Importance: Tinnitus retraining therapy (TRT) is an internationally recognized, but controversial, protocol of uncertain efficacy that uses tinnitus-specific educational counseling (TC) and sound therapy (ST) to reduce the patient's tinnitus-evoked negative reaction to, and awareness of, tinnitus. Objective: To compare the efficacy of TRT and its components, ST and TC, with the standard of care (SoC) in reducing the negative effect of tinnitus on quality of life. Design, Setting, and Participants: A randomized, placebo-controlled, multicenter phase 3 trial was conducted from August 4, 2011, to June 20, 2017, at 6 US military hospitals, the study chairs' office, and a data coordinating center, among 151 active-duty and retired military personnel and dependents with functionally adequate hearing sensitivity and moderate to severe subjective tinnitus. All analyses were based on intention to treat. Interventions: Central randomized allocation to TRT (TC and ST with conventional sound generators), partial TRT (TC with placebo sound generators), or SoC. Main Outcomes and Measures: The primary outcome was mean change on the Tinnitus Questionnaire (TQ), assessed longitudinally between baseline and 18 months after start of therapy. The secondary outcomes were changes in TQ subscales, Tinnitus Functional Index (TFI), and Tinnitus Handicap Inventory (THI) total and subscales, as well as a 10-point visual analog scale (VAS). Results: Among the 151 participants in the study (44 women and 107 men; mean [SD] age, 50.6 [11.3] years), 51 were randomized to receive TRT, 51 to receive partial TRT, and 49 to receive standard of care. Longitudinal analyses showed no difference between partial TRT or TRT compared with SoC, or partial TRT compared with TRT, on TQ, TFI, or THI total scores. Comparison of changes in mean score from baseline to the 18-month visit also showed no difference between treatment groups. Significant improvement was observed at 18 months in all treatment groups on TQ scores for TRT (effect size, -1.32; 95% CI, -1.78 to -0.85), partial TRT (effect size, -1.16; 95% CI, -1.56 to -0.76), and SoC (effect size, -1.01; 95% CI, -1.41 to -0.61). Compared with baseline scores, at 18 months there were reductions in scores by 7 points or more on the TQ score for 86 of 111 participants (77.55%; 95% CI, 69.7%-85.2%), 13 points or more on the TFI for 52 of 111 participants (46.8%; 95% CI, 37.6%-56.1%), 7 points or more on the THI for 63 of 111 participants (56.8%; 95% CI, 47.5%-66.0%), and 2 points or more on the VAS for 45 of 93 participants (48.4%; 95% CI, 38.2%-58.5%). Conclusions and Relevance: There were few differences between treatment groups. About half of participants showed clinically meaningful reductions in the effect of tinnitus. Trial Registration: ClinicalTrials.gov identifier: NCT01177137.

Group Means and Intersubject and Intrasubject Variability Estimates for Absolute and Relative (Categorical) Loudness Judgments of Typical Young Adult Listeners.

Purpose This brief research note is motivated by an ever-increasing need for typical repeated-measures loudness judgments and variability estimates of the kind necessary to conduct evidence-based treatment studies and clinical trials. Method These judgments and variability data, originally collected but not reported by Formby, Payne, Yang, Wu, and Parton (2017) , are presented here for relative (categorical) and absolute loudness judgments for typical young adult listeners with normal auditory function. Results As shown in this research note, these data may differ appreciably between young and older adult listeners with audiometric pure-tone thresholds within the clinically normal range. Conclusion In general, these findings highlight the need for good age-based, repeated-measures data for planning and powering evidence-based treatment studies and, specifically, for clinical trials that rely on categorical loudness judgments (i.e., as measured with the Contour Test of loudness; Cox, Alexander, Taylor, & Gray, 1997 ) as primary and secondary outcome measures.

Lessons learned conducting a multi-center trial with a military population: The Tinnitus Retraining Therapy Trial.

Background The Tinnitus Retraining Therapy Trial (TRTT), a randomized, placebo-controlled, multi-center trial, evaluated the efficacy of tinnitus retraining therapy and its individual components, tinnitus-specific educational counseling and sound therapy versus the standard of care, in military practice to improve study participants' quality of life. The trial was conducted at six US military hospitals to take advantage of the greater prevalence of tinnitus in the military population. Methods During the trial, various challenges arose that were uniquely related to the military setting. To convey these challenges to investigators planning future multi-center trials in military hospitals, we itemized various challenges that arose during the trial, interviewed clinic directors and coordinators to elicit their viewpoints, and then collated and organized their responses, together with those challenges presented while conducting the Tinnitus Retraining Therapy Trial. Results We encountered challenges in site selection, the approval process, administrative issues, study personnel training and retention, participant recruitment methods and issues, adherence to protocol, reimbursement issues, and military security. Site selection involved visiting 20 military hospitals to identify six sites that enrolled and followed study participants. We found that commitment for the trial must be obtained from the full military chain of command, but with ongoing changes in staff or military priorities, initial commitments were insufficient to sustain support throughout the entire trial. More time is required to obtain necessary administrative approvals by various military authorities and institutional review boards than is typically experienced in civilian settings. Recruitment strategies must be flexible due to changing military regulations regarding display of materials. Protracted periods of inactivity were due to sequestration and delays in institutional review board approval of required study personnel or protocol amendments. While mostly adherent to the protocol, study staff had difficulties in integrating study visits into the military clinical schedule. Unexpected study expenses revolved around hiring civilian study staff and obtaining associated security clearance while maintaining a consistent flow of funds to each site. The added expense negated cost savings realized by conducting the National Institutes of Health-funded trial at federal institutions, whose personnel could not be reimbursed for their efforts. Military security concerns impacted the use of web-based data systems and led to increased time and effort required for site visits. Conclusion Overall, US military hospitals provide a unique setting to conduct multi-center trials. Challenges arise mainly due to ever-changing authority personnel and military priorities. Pre-planning and flexibility are keys in overcoming these challenges. Multi-center trials conducted in the military will likely take longer to initiate and complete than those in the civilian sector due to multiple levels of command and administrative approvals.

Intra- and Intersubject Variability in Audiometric Measures and Loudness Judgments in Older Listeners with Normal Hearing.

This research was to document intra- and intersubject variability in measures of pure tone thresholds, loudness discomfort levels, and the Contour test of loudness for tonal and speech stimuli across 8 to 10 repeated test sessions over a period of almost 1 year in a group of 11 normal-hearing, older middle-aged adults (39 to 73 years, mean of 56 years). The measured pure tone thresholds and loudness discomfort levels were determined to be stable across sessions, with variability on the order of 5 dB. The categorical judgments for the Contour test for both warbled tones and spondaic speech stimuli decreased over time in level required for categories greater than comfortable. This result contrasts with reports of a slight increase over time when young, normal-hearing adults were tested in comparable measures. The intrasubject variability in the Contour test results was greatest for the 4,000-Hz tonal stimulus for which the largest time effects were observed. The intersubject variability was typically greater than the intrasubject variability and typically increased as the loudness category increased, with some exceptions. The results from this study can be used to aid in power and sample size analyses using these measures in future studies designed to compare effects of treatments based on changes in loudness judgments over time.

Repeated Measurement of Absolute and Relative Judgments of Loudness: Clinical Relevance for Prescriptive Fitting of Aided Target Gains for soft, Comfortable, and Loud, But Ok Sound Levels.

This study was undertaken with the purpose of streamlining clinical measures of loudness growth to facilitate and enhance prescriptive fitting of nonlinear hearing aids. Repeated measures of loudness at 500 and 3,000 Hz were obtained bilaterally at monthly intervals over a 6-month period from three groups of young adult listeners. All volunteers had normal audiometric hearing sensitivity and middle ear function, and all denied problems related to sound tolerance. Group 1 performed judgments of soft and loud, but OK for presentation of ascending sound levels. We defined these judgments operationally as absolute judgments of loudness. Group 2 initially performed loudness judgments across a continuum of seven loudness categories ranging from judgments of very soft to uncomfortably loud for presentation of ascending sound levels per the Contour Test of Loudness; we defined these judgments as relative judgments of loudness. In the same session, they then performed the absolute judgments for soft and loud, but OK sound levels. Group 3 performed the same set of loudness judgments as did group 2, but the task order was reversed such that they performed the absolute judgments initially within each test session followed by the relative judgments. The key findings from this study were as follows: (1) Within group, the absolute and relative tasks yielded clinically similar judgments for soft and for loud, but OK sound levels. These judgments were largely independent of task order, ear, frequency, or trial order within a given session. (2) Loudness judgments increased, on average, by ∼3 dB between the first and last test session, which is consistent with the commonly reported acclimatization effect reported for incremental changes in loudness discomfort levels as a consequence of chronic bilateral hearing aid use. (3) Measured and predicted comfortable judgments of loudness were in good agreement for the individual listener and for groups of listeners. These comfortable judgments bisect the measured levels judged for soft and for loud, but OK sounds. (4) Loudness judgments within the same loudness category varied across listeners within group by as much as 50 to 60 dB. Such large variation in judgments of loudness is problematic, especially because hearing-impaired listeners are known to exhibit similarly large ranges of intersubject response variation and, yet, poplar prescriptive fitting strategies continue to use average rather than individual loudness data to fit nonlinear hearing aids. The primary conclusions drawn from these findings are that reliable absolute judgments of soft and loud, but OK are clinically practical and economical to measure and, from these judgments, good estimates of comfortable loudness can also be predicted for individuals or for groups of listeners. Such loudness data, as measured as described in this report, offer promise for streamlining and enhancing prescriptive fitting of nonlinear hearing aids to target gain settings for soft (audible), comfortable, and loud, but OK (tolerable) sound inputs for the individual listener.

Considerations in the Development of a Sound Tolerance Interview and Questionnaire Instrument.

Most clinicians approach the objective fitting of hearing aids with three goals in mind: audibility, comfort, and tolerance. When these three amplification goals have been met, the hearing aid user is more likely to adapt to and perceive benefit from hearing aid use. However, problems related to the loudness of sounds and reduced sound tolerance, which may or may not be reported by the aided user, can adversely impact adaptation to amplification and the individual's quality of life. Although there are several standardized questionnaires available to evaluate hearing aid benefit and satisfaction, there is no standardized questionnaire or interview tool for evaluating reduced sound tolerance and the related impact on hearing aid use. We describe a 36-item tool, the Sound Tolerance Questionnaire (STQ), consisting of six sections, including experience with hearing aids, sound sensitivity/intolerance, medical and noise exposure histories, coexisting tinnitus problems, and a final question to differentiate the primary and secondary problems related to sound intolerance, tinnitus, and hearing loss. In its current format as a research tool, the STQ was sensitive in pinpointing vague sound tolerance complaints not reported by the study participants in eligibility screening by Formby et al. A refined version of the STQ, the Sound Tolerance Interview and Questionnaire Instrument (STIQI), structured as a two-part tool, is presented in the appendix for prospective clinical use. The STIQI has potential utility to delineate factors contributing to loudness complaints and/or reduced sound tolerance in individuals considering hearing aid use, as well as those who have been unsuccessful hearing aid users secondary to loudness complaints or sound intolerance. The STIQI, when validated and refined, also may hold promise for predicting hearing aid benefit and/or assessing treatment-related change over time of hearing aid use or interventions designed to remediate problems of loudness and/or sound intolerance among hearing aid candidates or users.

Relations among Auditory Brainstem and Middle Latency Response Measures, Categorical Loudness Judgments, and Their Associated Physical Intensities.

This study characterizes changes in response properties of toneburst-evoked auditory brainstem responses (ABRs) and/or middle latency responses (MLRs) as a function of perceived loudness and physical intensity of these stimuli and delineates the range of levels corresponding to categorical loudness judgments for these stimuli. ABRs/MLRs were recorded simultaneously to 500- and 2,000-Hz tonebursts in 10 normal-hearing adults at levels corresponding to each listener's loudness judgments for four categories on Contour Test of Loudness. Group mean ABR wave V and MLR wave Pa latency values increased significantly as loudness judgments decreased. Group mean amplitude values for ABR wave V-V' and MLR wave Na-Pa increased as the listeners' categorical judgments increased. Listeners assigned a broad range (30 to 40 dB) of stimulus intensities when judging loudness of these stimuli within a specific loudness category. This was true for all four loudness categories and both frequencies. Thus, it appears that tone-evoked ABR/MLR response measures reflect, in part, the listener's perception of loudness. Response latencies are a more sensitive indicator of listener's loudness percept than corresponding response amplitudes. An appreciable range of signal levels was judged to be categorically equivalent across listeners. Thus, limiting how loudness judgments can be applied to prescriptive hearing aid fittings in individuals who cannot provide accurate loudness judgments.

Auditory Brainstem and Middle Latency Responses Measured Pre- and Posttreatment for Hyperacusic Hearing-Impaired Persons Successfully Treated to Improve Sound Tolerance and to Expand the Dynamic Range for Loudness: Case Evidence.

In this report of three cases, we consider electrophysiologic measures from three hyperacusic hearing-impaired individuals who, prior to treatment to expand their dynamic ranges for loudness, were problematic hearing aid candidates because of their diminished sound tolerance and reduced dynamic ranges. Two of these individuals were treated with structured counseling combined with low-level broadband sound therapy from bilateral sound generators and the third case received structured counseling in combination with a short-acting placebo sound therapy. Each individual was highly responsive to his or her assigned treatment as revealed by expansion of the dynamic range by at least 20 dB at one or more frequencies posttreatment. Of specific interest in this report are their latency and amplitude measures taken from tone burst-evoked auditory brainstem response (ABR) and cortically derived middle latency response (MLR) recordings, measured as a function of increasing loudness at 500 and 2,000 Hz pre- and posttreatment. The resulting ABR and MLR latency and amplitude measures for each case are considered here in terms of pre- and posttreatment predictions. The respective pre- and posttreatment predictions anticipated larger pretreatment response amplitudes and shorter pretreatment response latencies relative to typical normal control values and smaller normative-like posttreatment response amplitudes and longer posttreatment response latencies relative to the corresponding pretreatment values for each individual. From these results and predictions, we conjecture about the neural origins of the hyperacusis conditions (i.e., brainstem versus cortical) and the neuronal sites responsive to treatment. The only consistent finding in support of the pre- and posttreatment predictions and, thus, the strongest index of hyperacusis and positive treatment-related effects was measured for MLR latency responses for wave Pa at 2,000 Hz. Other response indices, including ABR wave V latency and wave V-V' amplitude and MLR wave Na-Pa amplitude for 500 and 2,000 Hz, appear either ambiguous across and/or within these individuals. Notwithstanding significant challenges for interpreting these findings, including associated confounding effects of their sensorineural hearing losses and differences in the presentation levels of the toneburst stimuli used to collect these measures for each individual, our limited analyses of three cases suggest measures of MLR wave Pa latency at 2,000 Hz (reflecting cortical contributions) may be a promising objective indicator of hyperacusis and dynamic range expansion treatment effects.

Structured Counseling for Auditory Dynamic Range Expansion.

A structured counseling protocol is described that, when combined with low-level broadband sound therapy from bilateral sound generators, offers audiologists a new tool for facilitating the expansion of the auditory dynamic range (DR) for loudness. The protocol and its content are specifically designed to address and treat problems that impact hearing-impaired persons who, due to their reduced DRs, may be limited in the use and benefit of amplified sound from hearing aids. The reduced DRs may result from elevated audiometric thresholds and/or reduced sound tolerance as documented by lower-than-normal loudness discomfort levels (LDLs). Accordingly, the counseling protocol is appropriate for challenging and difficult-to-fit persons with sensorineural hearing losses who experience loudness recruitment or hyperacusis. Positive treatment outcomes for individuals with the former and latter conditions are highlighted in this issue by incremental shifts (improvements) in LDL and/or categorical loudness judgments, associated reduced complaints of sound intolerance, and functional improvements in daily communication, speech understanding, and quality of life leading to improved hearing aid benefit, satisfaction, and aided sound quality, posttreatment.