Military and Nonmilitary TBI Associations with Hearing Loss and Self-Reported Hearing Difficulty among Active-Duty Service Members and Veterans.

OBJECTIVE: Identify associations between self-reported history of military and nonmilitary traumatic brain injury (TBI) on hearing loss and hearing difficulty from the Noise Outcomes in Servicemembers Epidemiology (NOISE) study. STUDY DESIGN: Cross-sectional. SETTING: Multi-institutional tertiary referral centers. PATIENTS: Four hundred seventy-three Active-Duty Service members (ADSM) and 502 veterans. EXPOSURE: Self-reported history of no TBI, military TBI only, nonmilitary TBI only, both military and nonmilitary TBI. MAIN OUTCOME MEASURES: Pure-tone hearing thresholds, Speech Recognition In Noise Test (SPRINT), Hearing Handicap Inventory for Adults (HHIA), and Speech, Spatial and Qualities of Hearing Scale (SSQ)-12. RESULTS: 25% (120/473) of ADSM and 41% (204/502) of veterans self-reported a TBI. Military TBI was associated with poorer hearing thresholds in all frequency ranges in veterans (adjusted mean difference, 1.8 dB; 95% confidence interval [CI], 0.5-3.0; 3.3, 0.8-5.8; 5.1; 1.7-8.5, respectively), and in the high frequency range in ADSM (mean difference, 3.2 dB; 95% CI, 0.1-6.3). Veterans with military TBI only and nonmilitary TBI only had lower odds of correctly identifying speech in noise than veterans with no TBI (odds ratio [OR], 0.78; 95% CI, 0.72-0.83; 0.90; 0.84-0.98). ADSM with a military TBI (OR, 5.7; 95% CI, 2.6-12.5) and veterans with any TBI history (OR, 2.5; 95% CI, 1.5-4.3; OR, 2.2; 95% CI, 1.3-3.8; OR, 4.5; 95% CI, 2.1-9.8) were more likely to report hearing difficulty on HHIA. SSQ-12 results corroborated HHIA findings. CONCLUSIONS: Military TBI was associated with poorer hearing thresholds in veterans and ADSM, and poorer SPRINT scores in veterans. Military TBI was associated with poorer self-perceived hearing ability in ADSM. All types of TBI were associated with poorer self-perceived hearing ability in veterans, although the strength of this association was greatest for military TBI.

Tinnitus Screener: Short-Term Test-Retest Reliability.

PURPOSE: The Tinnitus Screener was introduced in 2015 as a four-item algorithmic instrument to assess the temporal characteristics of a person's reported tinnitus. The Tinnitus Screener was then revised as a six-item version to include a new temporal category and to capture tinnitus duration (acute < 6 months vs. chronic ≥ 6 months). When contrasted with audiologist assessment, the four-item Tinnitus Screener was determined to be highly valid, but the short-term reliability of either version remained unknown. The present analysis focused on determining the test-retest reliability of the six-item Tinnitus Screener. Additionally, we sought to determine whether reliability differed by respondent age, sex, military status, and hearing loss. METHOD: The Tinnitus Screener was administered to 190 military Service members and 250 military Veterans at two time points separated by 7-31 days. Our analysis focused on test-retest reliability of responses as measured by the kappa coefficient, overall and within subsamples. Percent agreement of tinnitus categorization (temporal categories) and classification (positive/negative) between the two time points was also evaluated. RESULTS: Constant or intermittent tinnitus was found in 31% of Service members and 53% of Veterans. Overall, kappa reliability coefficients were high, near .80, indicating substantial reliability. The majority (96%) of reliability coefficients for the Tinnitus Screener within subsamples were similarly high, ranging from .68 to .88. CONCLUSIONS: The updated version of the Tinnitus Screener is shown to be a reliable instrument. The Tinnitus Screener is recommended to inform clinical decision making by determining the temporal characteristics of tinnitus.

Associations between medical conditions and auditory dysfunction in US Veterans.

OBJECTIVE: To examine associations between non-otologic medical conditions and auditory dysfunction. DESIGN: Cross-sectional analysis of baseline data from the Noise Outcomes in Service members Epidemiology (NOISE) study. Logistic regression was used to estimate the association between medical conditions (0, 1, and 2 or more conditions) and auditory dysfunction (hearing loss pure tone average ≥20 dB HL and tinnitus), adjusting for key confounders including noise exposure. Secondarily, the association between specific medical conditions and auditory dysfunction was examined. All variables were self-reported. STUDY SAMPLE: United States military Veterans (n = 580) with mean age 34.1 years (standard deviation = 9.2), who were within approximately 2.5 years of separation from service. RESULTS: Compared to Veterans reporting no medical conditions, Veterans reporting two or more had increased odds on low-frequency hearing loss and on tinnitus but not on high or extended-high frequency hearing loss. Furthermore, specific conditions sleep disorder and arthritis were associated with auditory dysfunction. CONCLUSIONS: Non-otologic medical conditions were associated with low-frequency hearing loss and tinnitus in this sample of young Veterans. This suggests medical conditions may play a role in Veterans' hearing health. Whether management of medical conditions earlier in life reduces the risk of hearing loss and tinnitus requires further study.

Oddball paradigm complexity in multi-token auditory evoked potentials.

We developed and tested a series of novel and increasingly complex multi-token electrophysiology paradigms for evoking the auditory P3 response. The primary goal was to evaluate the degree to which more complex discrimination tasks and listening environments - which are more likely to engage the types of neural processing used in real-world speech-in-noise situations - could still evoke a robust P3 response. If so, this opens the possibility of such a paradigm making up part of the toolkit for a brain-behavioral approach to improve understanding of speech processing. Fourteen normal-hearing adults were tested using four different auditory paradigms consisting of 5 tokens, 20 tokens, 160 tokens, or 160 tokens with background babble. Stimuli were naturally produced consonant-vowel tokens varying in consonant (/d/, /b/, /g/, /v/, and /ð/; all conditions), vowel (/ɑ/, /u/, /i/, and /ɜr/; 20- and 160-token conditions), and talker (4 female, 4 male; 160-token conditions only). All four conditions evoked robust neural responses, and all peaks had visible differences across conditions. However, the more exogenous auditory evoked potentials (N1 and P2) were primarily affected not by overall complexity but by the presence of background noise specifically, the presence of which was associated with longer latencies and smaller amplitudes. The more endogenous P3 peak, as well as the paradigm behavioral measures, revealed a more graded effect of overall paradigm complexity, rather than the background noise dominating the other factors. Our conclusion was that all four complex auditory paradigms, including the most complex (160 distinct consonant-vowel tokens presented in background babble), are viable means of stimulating N1-P2 and N2b-P3 auditory evoked responses and may therefore be useful in brain-behavioral approaches to understanding speech perception in noise.

Tinnitus: An Epidemiologic Perspective.

Tinnitus is commonly referred to as "ringing in the ears." Epidemiologic studies highlight challenges associated with clinical determination of tinnitus and ascertainment of its etiology, functional effects, temporal characteristics, psychoacoustic parameters, and risk factors. Because no standards exist for capturing these factors as measures, direct comparison of data between studies is not possible. This report suggests terminology and definitions to promote standardization, with a brief overview of findings from selected population-based epidemiologic studies. Tinnitus-specific data are presented from the Noise Outcomes in Servicemembers Epidemiology study. Further epidemiologic studies are needed to develop tinnitus treatment and a cure for this chronic condition.

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.

Acoustic change complex in background noise: phoneme level and timing effects.

The effects of background noise on speech-evoked cortical auditory evoked potentials (CAEPs) can provide insight into the physiology of the auditory system. The purpose of this study was to determine background noise effects on neural coding of different phonemes within a syllable. CAEPs were recorded from 15 young normal-hearing adults in response to speech signals /s/, /ɑ/, and /sɑ/. Signals were presented at varying signal-to-noise ratios (SNRs). The effects of SNR and context (in isolation or within syllable) were analyzed for both phonemes. For all three stimuli, latencies generally decreased and amplitudes generally increased as SNR improved, and context effects were not present; however, the amplitude of the /ɑ/ response was the exception, showing no SNR effect and a significant context effect. Differential coding of /s/ and /ɑ/ likely result from level and timing differences. Neural refractoriness may result in the lack of a robust SNR effect on amplitude in the syllable context. The stable amplitude across SNRs in response to the vowel in /sɑ/ suggests the combined effects of (1) acoustic characteristics of the syllable and noise at poor SNRs and (2) refractory effects resulting from phoneme timing at good SNRs. Results provide insights into the coding of multiple-onset speech syllables in varying levels of background noise and, together with behavioral measures, may help to improve our understanding of speech-perception-in-noise difficulties.

Signal type and signal-to-noise ratio interact to affect cortical auditory evoked potentials.

Use of speech signals and background noise is emerging in cortical auditory evoked potential (CAEP) studies; however, the interaction between signal type and noise level remains unclear. Two experiments determined the interaction between signal type and signal-to-noise ratio (SNR) on CAEPs. Three signals (syllable /ba/, 1000-Hz tone, and the /ba/ envelope with 1000-Hz fine structure) with varying SNRs were used in two experiments, demonstrating signal-by-SNR interactions due to both envelope and spectral characteristics. When using real-world stimuli such as speech to evoke CAEPs, temporal and spectral complexity leads to differences with traditional tonal stimuli, especially when presented in background noise.