The influence of tinnitus and hearing loss on the functional status of military Service members and Veterans.

OBJECTIVE: This study evaluated the influence of tinnitus and hearing loss on the functional status of military Service members and Veterans. DESIGN: Participants completed audiologic testing and self-report instruments to assess tinnitus, hearing, and general functioning. We conducted multiple linear regression analyses using cross-sectional data with functional status as the dependent variable. The primary independent variables were tinnitus and average low-, high-, and extended high-frequency hearing thresholds. Secondary independent variables were subjective tinnitus severity and hearing difficulties. Each of the independent variables was modelled separately for Service members and Veterans; covariates for each multivariable model were identified a priori and, depending on the association being modelled, included age, gender, blast-wave exposure, and history of military traumatic brain injury. STUDY SAMPLE: Data were analysed from 283 Service members and 390 Veterans. RESULTS: After controlling for potential confounders, presence of tinnitus, tinnitus severity, average low-frequency hearing thresholds, and subjective hearing difficulties were significantly associated with functional status in Service members and Veterans. CONCLUSIONS: These results suggest that tinnitus and poorer low-frequency hearing, and the perceived severity of tinnitus and hearing difficulties, may be associated with poorer functional status among Service members and Veterans.

Blast Exposure and Self-Reported Hearing Difficulty in Service Members and Veterans Who Have Normal Pure-Tone Hearing Sensitivity: The Mediating Role of Posttraumatic Stress Disorder.

Purpose Evidence suggests that military blast exposure may lead to self-reported hearing difficulties despite audiometrically normal hearing. Research identifying potential mechanisms of this association remains limited. The purpose of this article is to evaluate the associations between blast, posttraumatic stress disorder (PTSD), and self-reported hearing difficulty, and to examine PTSD as a possible mediator of the association between blast exposure and hearing difficulty. Method We used baseline data from the Noise Outcomes in Service members Epidemiology (NOISE) study (n = 477). Participants in this study undergo a comprehensive hearing, and tinnitus if applicable, evaluation and complete a large number of surveys. Pertinent data extracted from these surveys included information on participant's demographics, military service history, including exposure to blast, and health conditions such as symptoms of PTSD. Using regression models and following a formal causal mediation framework, we estimated total associations, natural direct and indirect associations, and percent mediated. Results We found that individuals with blast exposure had higher prevalence of both probable PTSD and self-reported hearing difficulty than individuals who were not blast exposed. Compared with participants without blast exposure, those with blast exposure had twice the prevalence of self-reported hearing difficulty, with 41% of the association mediated through probable PTSD. Conclusion As PTSD is a possible mediator of the association between blast exposure and hearing difficulty, Service members and Veterans with normal pure-tone hearing sensitivity who report hearing difficulties and a history of blast exposure may benefit from evaluation for PTSD symptoms. Supplemental Material https://doi.org/10.23641/asha.16674247.

Heterogeneity in Vision, Hand Function, Cognition, and Health Literacy Among Older Veterans: Impacts, Outcomes, and Clinical Recommendations for First-Time Hearing Aid Users.

BACKGROUND: Age-related changes (both normal and pathological), and health literacy are relevant to audiological practice. Changes associated with the musculoskeletal, vascular, and nervous systems drive manual, visual, and cognitive function. These in turn affect the capabilities required for effective hearing aid (HA) skill acquisition, use, and management. Meanwhile, health literacy influences the ability to gain access to, understand, and use information, which is important for promoting and maintaining HA use and management. Understanding the interindividual variability of these variables can help audiologists characterize those individuals who might have suboptimal HA outcomes. This knowledge can then inform better clinical practices and guide implementation of processes to improve care quality and outcomes. PURPOSE: The aim of the study is to assess the variation in manual, visual, and cognitive function, and health literacy, among community-dwelling older individuals, and to determine whether and which of these variables are associated with reported HA outcome and/or the knowledge and skill to manage HAs. RESEARCH DESIGN: Data presented here were collected as part of an efficacy trial of four variants of HA orientation. The data were collected at baseline (prior to HA fitting) and after 4 to 8 weeks of HA use. STUDY SAMPLE: The study sample consists of 265 U.S. Veterans aged 51 to 87 years with no previous HA experience who were scheduled to receive their first pair of HAs from the Veterans Administration. DATA COLLECTION AND ANALYSIS: We assessed baseline measures of hand function, vision, cognition, and health literacy just prior to participants receiving their first pair of HAs. HA management skills and knowledge, and HA outcome were measured after 4 to 8 weeks of HA use using the Hearing Aid Skills and Knowledge (HASK) and International Outcomes Inventory for Hearing Aids (IOI-HA), respectively. Data collected here was compared with published norms to assess variation in baseline measures. Associations between baseline performance and outcomes data were examined using t-tests comparing participants who performed at or above age-based norms with those who performed below age-based norms. RESULTS: Participants' performance on the baseline measures was highly variable, with the proportions of individuals performing below norms varying by test measure. When combining data across the nine baseline measures, approximately 10% of participants performed below published norms on five or more measures, and 85% performed below norms on at least one measure. Poor manual dexterity, ability to learn a new task, and ability to draw inferences from spoken information negatively impacted HA management and outcome. CONCLUSION: There was a considerable heterogeneity among a community-dwelling sample of first time HA users in terms of sensory, cognitive, and motor function. Clinicians should consider modifying their clinical practice to account for such heterogeneity and best support their patients in adapting to new HAs.

Acquired Central Auditory Processing Disorder in Service Members and Veterans.

Purpose A growing body of evidence suggests that military service members and military veterans are at risk for deficits in central auditory processing. Risk factors include exposure to blast, neurotrauma, hazardous noise, and ototoxicants. We overview these risk factors and comorbidities, address implications for clinical assessment and care of central auditory processing deficits in service members and veterans, and specify knowledge gaps that warrant research. Method We reviewed the literature to identify studies of risk factors, assessment, and care of central auditory processing deficits in service members and veterans. We also assessed the current state of the science for knowledge gaps that warrant additional study. This literature review describes key findings relating to military risk factors and clinical considerations for the assessment and care of those exposed. Conclusions Central auditory processing deficits are associated with exposure to known military risk factors. Research is needed to characterize mechanisms, sources of variance, and differential diagnosis in this population. Existing best practices do not explicitly consider confounds faced by military personnel. Assessment and rehabilitation strategies that account for these challenges are needed. Finally, investment is critical to ensure that Veterans Affairs and Department of Defense clinical staff are informed, trained, and equipped to implement effective patient care.

Description, Normative Data, and Utility of the Hearing Aid Skills and Knowledge Test.

BACKGROUND: The ability to manage hearing aids is crucial for successful outcomes and for maintaining hearing aid use. It is therefore important to have a tool that can effectively identify which hearing aid management skills are lacking so that the audiologist can provide additional education and training on that skill. Such a tool can also provide useful quantitative data for researchers. PURPOSE: To collect normative data (Experiment 1) and assess inter- and intrarater reliability (Experiment 2) for a hearing aid management assessment tool known as the Hearing Aid Skills and Knowledge (HASK) test. STUDY SAMPLE: Two hundred thirty-six new hearing aid users recruited from the VA Portland Health Care System and 126 experienced hearing aid users recruited from the local Portland community participated in Experiment 1. The veteran participants were taking part in a larger hearing aid study, and the community participants were recruited at community events that took place around Portland, OR. Three clinical audiologists and two AuD students completing their fourth year externship participated in Experiment 2. DATA COLLECTION AND ANALYSIS: In Experiment 1, HASK data were collected from the new hearing aid users at 4-8 wk and 6-8 mo after the fitting of their first pair of hearing aids, and from experienced users on a single occasion. In addition, self-reported hearing aid use, benefit, and satisfaction were assessed for all participants. The audiologists/students in Experiment 2 watched and independently scored videos of six individuals completing the HASK. Intraclass correlation coefficients (ICCs) across audiologists were computed for HASK scores. Three audiologists/students rated at least one video on two occasions to provide interrater reliability data. RESULTS: Mean performance on the HASK was about 70% for knowledge and 80% for skills for both the new and experienced hearing aid users. Performance did not change among the new users between the 4-8 wk and 6-8 mo administration. The specific skills lacking were associated with advanced management abilities (cleaning and troubleshooting). Experiment 2 revealed ICCs for inter- and intrarater reliability for HASK to range from 0.76 to 0.94, showing acceptable to excellent reliability. CONCLUSIONS: The HASK is a quick and easy test with good-to-excellent inter- and intrarater reliability. It can effectively identify which hearing aid management skills are lacking so that the audiologist can provide additional education and training on those skills. Data show performance is ∼70% for knowledge and 80% for skills and this does not change with hearing aid experience. The significant positive correlations between HASK scores and hearing aid use and satisfaction highlight the notion that ability to manage hearing aids successfully is integral to good hearing aid outcome.

Hearing complaints among veterans following traumatic brain injury.

It has been shown that there is an increased risk for impaired auditory function following traumatic brain injury (TBI) in Veterans. Evidence is strongest in the area of self-report, but behavioural and electrophysiological data have been obtained that are consistent with these complaints. Peripheral and central dysfunction have both been observed. Historically, studies have focused on penetrating head injuries where central injury is more easily documented than in mild closed head injuries, but several recent reports have expanded the literature to include closed head injuries as well. The lack of imaging technology that can identify which closed head injuries are likely to impact auditory function is a significant barrier to accurate diagnosis and rehabilitation. Current behavioural and electrophysiological measures are effective in substantiating the auditory complaints of these patients but leave many questions unanswered. One significant limitation of current approaches is the lack of clear data regarding the potential influence of those mental health comorbidities that are very likely to be present in the Veteran population. In the area of rehabilitation, there are indications that hearing aids and other assistive listening devices may provide benefit, as can auditory training programmes, yet more research needs to be done.

Tinnitus Screener: Results From the First 100 Participants in an Epidemiology Study.

PURPOSE: In the Noise Outcomes in Servicemembers Epidemiology Study, Veterans recently separated from the military undergo comprehensive assessments to initiate long-term monitoring of their auditory function. We developed the Tinnitus Screener, a four-item algorithmic instrument that determines whether tinnitus is present and, if so, whether it is constant or intermittent, or whether only temporary tinnitus has been experienced. Predictive validity data are presented for the first 100 Noise Outcomes in Servicemembers Epidemiology Study participants. METHOD: The Tinnitus Screener was administered to participants by telephone. In lieu of a gold standard for determining tinnitus presence, the predictive validity of the tinnitus category assigned to participants on the basis of the Screener results was assessed when the participants attended audiologic testing. RESULTS: Of the 100 participants, 67 screened positive for intermittent or constant tinnitus. Three were categorized as "temporary" tinnitus only, and 30 were categorized as "no tinnitus." Tinnitus categorization was predictively valid with 96 of the 100 participants. CONCLUSIONS: These results provide preliminary evidence that the Screener may be suitable for quickly determining essential parameters of reported tinnitus. We have since revised the instrument to differentiate acute from chronic tinnitus and to identify occasional tinnitus. We are also obtaining measures that will enable assessment of its test-retest reliability.

Hearing impairment and tinnitus: prevalence, risk factors, and outcomes in US service members and veterans deployed to the Iraq and Afghanistan wars.

Hearing loss and tinnitus are the 2 most prevalent service-connected disabilities among veterans in the United States. Veterans of Operations Enduring Freedom, Iraqi Freedom, and New Dawn have been exposed to multiple hazards associated with these conditions, such as blasts/explosions, ototoxic chemicals, and most notably high levels of noise. We conducted a systematic literature review of evidence on 1) prevalence of, 2) risk and protective factors for, and 3) functional and quality-of-life outcomes of hearing impairment and tinnitus in US Operations Enduring Freedom, Iraqi Freedom, and New Dawn veterans and military personnel. We identified studies published from 2001 through 2013 using PubMed, PsycINFO, REHABDATA, Cochrane Library, pearling, and expert recommendation. Peer-reviewed English language articles describing studies of 30 or more adults were included if they informed one or more key questions. A total of 839 titles/abstracts were reviewed for relevance by investigators trained in critical analysis of literature; 14 studies met inclusion criteria. Of these, 13 studies presented data on prevalence and 4 on risk/protective factors, respectively. There were no included studies reporting on outcomes. Findings from this systematic review will help inform clinicians, researchers, and policy makers on future resource and research needs pertaining to hearing impairment and tinnitus in this newest generation of veterans.

Does interferon beta-1a impact pure-tone hearing sensitivity among individuals with multiple sclerosis?

BACKGROUND: Previous studies reported that particular types of interferon medications might contribute to hearing loss in some patients. The package insert included in the original Food and Drug Administration application for intramuscular interferon beta-1a (Avonex) stated that some patients in the treatment group reported decreased hearing sensitivity. OBJECTIVE: The purpose of the present investigation was to assess if individuals with multiple sclerosis (MS) taking intramuscular interferon beta-1a have significantly poorer hearing thresholds than those not currently using any disease-modifying therapies. METHODS: This was a secondary analysis of data collected as part of two larger studies evaluating auditory function in patients with MS. The goal of this analysis was to determine if users of interferon beta-1a do not have significantly worse hearing thresholds than nonusers of disease-modifying therapies, after adjusting for potential confounders. A linear mixed model was fit to the audiometric thresholds of our subjects. This model included interferon beta-1a use, MS disease subtype, gender, test frequency, age, disease duration (number of years), and the Expanded Disability Status Scale score. RESULTS AND CONCLUSIONS: With all subjects included, there is insufficient evidence to say that intramuscular interferon-beta 1a is not ototoxic (in relation to nonuse of a disease-modifying therapy) at all frequencies tested except 3000 and 6000 Hz. After removing two influential subjects, the results indicated that there is statistical support for no ototoxic effect of intramuscular interferon beta-1a at test frequencies from 250 to 6000 Hz. There is insufficient evidence, however, to rule out an ototoxic effect at 8000 Hz. Future studies should further evaluate the effect of interferon on auditory function in patients with MS. Neuroscience nurses should monitor their patients' hearing throughout the course of treatment.

Performance on tests of central auditory processing by individuals exposed to high-intensity blasts.

Thirty-six blast-exposed patients and twenty-nine non-blast-exposed control subjects were tested on a battery of behavioral and electrophysiological tests that have been shown to be sensitive to central auditory processing deficits. Abnormal performance among the blast-exposed patients was assessed with reference to normative values established as the mean performance on each test by the control subjects plus or minus two standard deviations. Blast-exposed patients performed abnormally at rates significantly above that which would occur by chance on three of the behavioral tests of central auditory processing: the Gaps-In-Noise, Masking Level Difference, and Staggered Spondaic Words tests. The proportion of blast-exposed patients performing abnormally on a speech-in-noise test (Quick Speech-In-Noise) was also significantly above that expected by chance. These results suggest that, for some patients, blast exposure may lead to difficulties with hearing in complex auditory environments, even when peripheral hearing sensitivity is near normal limits.

Implications of blast exposure for central auditory function: a review.

Auditory system functions, from peripheral sensitivity to central processing capacities, are all at risk from a blast event. Accurate encoding of auditory patterns in time, frequency, and space are required for a clear understanding of speech and accurate localization of sound sources in environments with background noise, multiple sound sources, and/or reverberation. Further work is needed to refine the battery of clinical tests sensitive to the sorts of central auditory dysfunction observed in individuals with blast exposure. Treatment options include low-gain hearing aids, remote-microphone technology, and auditory-training regimens, but clinical evidence does not yet exist for recommending one or more of these options. As this population ages, the natural aging process and other potential brain injuries (such as stroke and blunt trauma) may combine with blast-related brain changes to produce a population for which the current clinical diagnostic and treatment tools may prove inadequate. It is important to maintain an updated understanding of the scope of the issues present in this population and to continue to identify those solutions that can provide measurable improvements in the lives of Veterans who have been exposed to high-intensity blasts during the course of their military service.

Development of a "virtual cocktail party" for the measurement of speech intelligibility in a sound field.

This technical report describes an approach to the measurement of speech intelligibility for sentences presented in a sound field in the presence of 16-talker babble. More specifically, we detail our (1) selection and preparation of target speech materials, (2) selection and preparation of experimental babble, (3) analog instrumentation, (4) software routines for attenuator control, (5) calibration, (6) experimental subjects, and (7) experimental protocol. In the final section of this report we present speech-intelligibility data from 16 young adults (21-30 yr of age) with normal hearing sensitivity for pure-tone signals.

Audiometric hearing status of individuals with and without multiple sclerosis.

The purpose of the present investigation was to determine whether differences exist in audiometric hearing status between individuals with and without multiple sclerosis (MS) and between individuals with relapsing-remitting MS (RRMS) and individuals with secondary progressive MS (SPMS). Forty-seven subjects with MS (26 with RRMS and 21 with SPMS) and forty-nine control subjects without MS completed both a comprehensive case-history questionnaire and a conventional hearing evaluation. Statistical analyses, accounting for the potential confounding factors of age, sex, noise exposure, and use of ototoxic medications, revealed significant differences in hearing thresholds between subjects with and without MS at select audiometric test frequencies (p < 0.05). At these audiometric test frequencies, the subjects with MS had poorer hearing thresholds. Additional analyses revealed significant differences in hearing sensitivity at select audiometric frequencies between the subjects with RRMS and the subjects with SPMS, such that those with SPMS had poorer hearing thresholds. These findings have significant clinical implications for practitioners working with patients with MS.

Expectations, prefitting counseling, and hearing aid outcome.

BACKGROUND: Data suggest that having high expectations about hearing aids results in better overall outcome. However, some have postulated that excessively high expectations will result in disappointment and thus poor outcome. It has been suggested that counseling patients with unrealistic expectations about hearing aids prior to fitting may be beneficial. Data, however, are mixed as to the effectiveness of such counseling, in terms of both changes in expectations and final outcome. PURPOSE: The primary purpose of this study was to determine whether supplementing prefitting counseling with demonstration of real-world listening can (1) alter expectations of new hearing aid users and (2) increase satisfaction over verbal-only counseling. Secondary goals of the study were to examine (1) the relationship between prefitting expectations and postfitting outcome, and (2) the effect of hearing aid fine-tuning on hearing aid outcome. RESEARCH DESIGN: Sixty new hearing aid users were fitted binaurally with Beltone Oria behind-the-ear digital hearing aids. Forty participants received prefitting counseling and demonstration of listening situations with the Beltone AVE (Audio Verification Environment) system; 20 received prefitting counseling without a demonstration of listening situations. Hearing aid expectations were measured at initial contact and following prefitting counseling. Reported hearing aid outcome was measured after eight to ten weeks of hearing aid use. STUDY SAMPLE: Sixty new hearing aid users aged between 55 and 81 years with symmetrical sensorineural hearing loss. INTERVENTION: Participants were randomly assigned to one of three experimental groups, between which the prefitting counseling and follow-up differed: Group 1 received prefitting counseling in combination with demonstration of listening situations. Additionally, if the participant had complaints about sound quality at the follow-up visit, the hearing aids were fine-tuned using the Beltone AVE system. Group 2 received prefitting counseling in combination with demonstration of listening situations with the Beltone AVE system, but no fine-tuning was provided at follow-up. Group 3 received prefitting hearing aid counseling that did not include demonstration of listening, and the hearing aids were not fine-tuned at the follow-up appointment. RESULTS: The results showed that prefitting hearing aid counseling had small but significant effects on expectations. The two forms of counseling did not differ in their effectiveness at changing expectations; however, anecdotally, we learned from many participants that that they enjoyed listening to the auditory demonstrations and that they found them to be an interesting listening exercise. The data also show that positive expectations result in more positive outcome and that hearing aid fine-tuning is beneficial to the user. CONCLUSIONS: We conclude that prefitting counseling can be advantageous to hearing aid outcome and recommend the addition of prefitting counseling to address expectations associated with quality of life and self-image. The data emphasize the need to address unrealistic expectations prior to fitting hearing aids cautiously, so as not to decrease expectations to the extent of discouraging and demotivating the patient. Data also show that positive expectations regarding the impact hearing aids will have on psychosocial well-being are important for successful hearing aid outcome.

Frequency-modulation (FM) technology as a method for improving speech perception in noise for individuals with multiple sclerosis.

Almost half of the population with multiple sclerosis (MS) complains of difficulty hearing, despite having essentially normal pure-tone thresholds. The purpose of the present investigation was to evaluate the effects of frequency-modulation (FM) technology utilization on speech perception in noise for adults with and without MS. Sentence material was presented at a constant level of 65 dBA Leq from a loudspeaker located at 0 degrees azimuth. The microphone of the FM transmitter was placed 7.5 cm from this loudspeaker. Multitalker babble was presented from four loudspeakers positioned at 45 degrees, 135 degrees, 225 degrees, and 315 degrees azimuths. The starting presentation level for the babble was 55 dBA Leq, The level of the noise was increased systematically in 1 dB steps until the subject obtained 0% key words correct on the IEEE (Institute for Electrical and Electronic Engineers) sentences. Test results revealed significant differences between the unaided and aided conditions at several signal-to-noise ratios.

Some effects of multiple sclerosis on speech perception in noise: Preliminary findings.

The present investigation examined speech perception in noise of adults with and without multiple sclerosis (MS). Institute of Electrical and Electronic Engineers (IEEE) sentences were presented at a constant level of 65 dBA L(eq) (equivalent continuous noise level [4 dB exchange rate]) from a loudspeaker located at 0-degree horizontal azimuth and 1.2 m from the study participant. Uncorrelated multitalker babble was presented from four loudspeakers positioned at 45-, 135-, 225-, and 315-degree azimuths and 1.7 m from the study participant. The starting presentation level for the babble was 55 dBA L(eq). The level of the babble was increased systematically in 1 dB steps until the subject obtained 0% key words correct on the IEEE sentences. Results revealed a significant difference in speech perception between the two groups at nine signal-to-noise ratios. Some clinical implications of these results are discussed.

The effect of hearing aids and frequency modulation technology on results from the communication profile for the hearing impaired.

Hearing impairment has been associated with decline in psychosocial function. Previous investigations have reported that the utilization of hearing aids can ameliorate these reductions in psychosocial function. To date, few investigations have examined the effects of frequency modulation technology on hearing handicap, adjustment to hearing loss, and communicative strategies. The purpose of this investigation was to examine these effects and to compare them to the benefits obtained when using hearing aids alone. Subjects ranged in age from 34 to 81 years and had mean pure-tone thresholds consistent with a bilateral moderate to severe sloping sensorineural hearing loss. All subjects wore hearing aids only and hearing aids plus FM system in a randomized fashion. The Communication Profile for the Hearing Impaired (CPHI) was administered prior to fitting the study devices and once a month for three months in each of the two conditions. A statistically significant difference between device conditions was obtained for the Importance of Communication in Work Situations subscale. Additionally, statistically significant differences over time were noted in several CPHI subscales. Despite statistical significance, none of these results were clinically significant. The implications of these results will be discussed.

Speech perception in noise: directional microphones versus frequency modulation (FM) systems.

The major consequence of sensorineural hearing loss (SNHL) is communicative difficulty, especially with the addition of noise and/or reverberation. The purpose of this investigation was to compare two types of technologies that have been shown to improve the speech-perception performance of individuals with SNHL: directional microphones and frequency modulation (FM) systems. Forty-six adult subjects with slight to severe SNHL served as subjects. Speech perception was assessed using the Hearing in Noise Test (HINT) with correlated diffuse noise under five different listening conditions. Results revealed that speech perception was significantly better with the use of the FM system over that of any of the hearing aid conditions, even with the use of the directional microphone. Additionally, speech perception was significantly better with the use of two hearing aids used in conjunction with two FM receivers rather than with just one FM receiver. Directional microphone performance was significantly better than omnidirectional microphone performance. All aided listening conditions were significantly better than the unaided listening condition.

Effects of frequency modulation (FM) transmitter microphone directivity on speech perception in noise.

Frequency modulation (FM) technology can significantly improve the speech perception ability of individuals with sensorineural hearing loss (SNHL) in background noise. Previous investigations have demonstrated that the microphone design of the FM transmitter can have a significant impact on this improved speech perception. The purpose of this investigation was to compare 3 types of FM transmitter microphone designs: (a) wide angle (omnidirectional microphone), which amplifies sounds coming from all directions around the microphone equally; (b) zoom (1 directional microphone), which provides less amplification to signals coming from the rear, and (c) superzoom (2 directional microphones), which provides less amplification to signals originating from the rear and the sides. Fifteen adults with bilateral slight to moderately severe SNHL participated. Speech perception was assessed using the Hearing in Noise Test (M. Nilsson, S. Soli, and J. Sullivan, 1994). Speech spectrum shaped noise served as the noise competition. Results revealed that the best speech perception in noise was obtained when the FM transmitter was used in the zoom setting. The poorest performance was obtained when the FM transmitter was in the wide-angle mode. The clinical implications of these results are discussed.