Home Hearing Test: Within-Subjects Threshold Variability.

BACKGROUND: The Home Hearing Test (HHT) is an automated pure-tone threshold test that obtains an air conduction audiogram at five test frequencies. It was developed to provide increased access to hearing testing and support home telehealth programs. PURPOSE: Test and retest thresholds for 1000-Hz stimuli were analyzed to determine intrasubject variability from two independent data sets. RESEARCH DESIGN: Prospective, repeated measures. STUDY SAMPLE: In the Veterans Affairs (VA) study, results from 26 subjects 44 to 88 years of age (mean = 65) recruited from the Nashville VA audiology clinic were analyzed. Subjects were required to have a Windows PC in the home and were self-reported to be comfortable with using computers. Two subjects had normal hearing, and 24 had hearing losses of various severities and configurations. The National Center for Rehabilitative Auditory Research (NCRAR) sample included 100 subjects (68 males; 32 females) with a complaint of hearing difficulty recruited from the local community and Veteran population. Subjects ranged in age from 32 to 87 years (mean = 63.7 years). They were tested in a quiet room at the NCRAR. DATA COLLECTION AND ANALYSIS: Subjects in the VA study were provided kits for installing HHT on their home computers. HHT was installed on a computer at NCRAR to test subjects in the NCRAR study. HHT obtains a five-frequency air conduction audiogram with a retest of 1000 Hz in both ears. Only the 1000-Hz test-retest results are analyzed in this report. Six statistical measures of test-retest variability are reported. RESULTS: Test and retest thresholds were highly correlated in both studies (r ≥ 0.96). Test-retest differences were within ±5 dB ≥92% of the time in the two studies. Standard deviations of absolute test-retest difference were ≤3.5 dB in the two studies. CONCLUSIONS: Intrasubject variability is comparable to that obtained with manual testing by audiologists in sound-treated test rooms.

Style preference survey: a report on the psychometric properties and a cross-validation experiment.

BACKGROUND: Several self-report measures exist that target different aspects of outcomes for hearing aid use. Currently, no comprehensive questionnaire specifically assesses factors that may be important for differentiating outcomes pertaining to hearing aid style. PURPOSE: The goal of this work was to develop the Style Preference Survey (SPS), a questionnaire aimed at outcomes associated with hearing aid style differences. Two experiments were conducted. After initial item development, Experiment 1 was conducted to refine the items and to determine its psychometric properties. Experiment 2 was designed to cross-validate the findings from the initial experiment. RESEARCH DESIGN: An observational design was used in both experiments. STUDY SAMPLE: Participants who wore traditional, custom-fitted (TC) or open-canal (OC) style hearing aids from 3 mo to 3 yr completed the initial experiment. One-hundred and eighty-four binaural hearing aid users (120 of whom wore TC hearing aids and 64 of whom wore OC hearing aids) participated. A new sample of TC and OC users (n = 185) participated in the cross-validation experiment. DATA COLLECTION AND ANALYSIS: Currently available self-report measures were reviewed to identify items that might differentiate between hearing aid styles, particularly preference for OC versus TC hearing aid styles. A total of 15 items were selected and modified from available self-report measures. An additional 55 items were developed through consensus of six audiologists for the initial version of the SPS. In the first experiment, the initial SPS version was mailed to 550 veterans who met the inclusion criteria. A total of 184 completed the SPS. Approximately three weeks later, a subset of participants (n = 83) completed the SPS a second time. Basic analyses were conducted to evaluate the psychometric properties of the SPS including subscale structure, internal consistency, test-retest reliability, and responsiveness. Based on the results of Experiment 1, the SPS was revised. A cross-validation experiment was then conducted using the revised version of the SPS to confirm the subscale structure, internal consistency, and responsiveness of the questionnaire in a new sample of participants. RESULTS: The final factor analysis led to the ultimate version of the SPS, which had a total of 35 items encompassing five subscales: (1) Feedback, (2) Occlusion/Own Voice Effects, (3) Localization, (4) Fit, Comfort, and Cosmetics, and (5) Ease of Use. The internal consistency of the total SPS (Cronbach's α = .92) and of the subscales (each Cronbach's α > .75) was high. Intraclass correlations (ICCs) showed that the test-retest reliability of the total SPS (ICC = .93) and of the subscales (each ICC > .80) also was high. TC hearing aid users had significantly poorer outcomes than OC hearing aid users on 4 of the 5 subscales, suggesting that the SPS largely is responsive to factors related to style-specific differences. CONCLUSIONS: The results suggest that the SPS has good psychometric properties and is a valid and reliable measure of outcomes related to style-specific, hearing aid preference.

Evaluation of audiometric threshold shift criteria for ototoxicity monitoring.

BACKGROUND: There is disagreement about ototoxicity monitoring methods. Controversy exists about what audiometric threshold shift criteria should be used, which frequencies should be tested, and with what step size. An evaluation of the test performance achieved using various criteria and methods for ototoxicity monitoring may help resolve these issues. PURPOSE: (1) Evaluate test performance achieved using various significant threshold shift (STS) definitions for ototoxicity monitoring in a predominately veteran population; and (2) determine whether testing in (1/6)- or (1/3)-octave steps improves test performance compared to (1/2)-octave steps. RESEARCH DESIGN: A prospective, observational study design was used in which STSs were evaluated at frequencies within an octave of each subject's high-frequency hearing limit at two time points, an early monitoring test and the final monitoring test. STUDY SAMPLE: Data were analyzed from 78 ears of 41 patients receiving cisplatin and from 53 ears of 28 hospitalized patients receiving nonototoxic antibiotics. Cisplatin-treated subjects received a cumulative dosage > or =350 mg by the final monitoring test. Testing schedule, age, and pre-exposure hearing characteristics were similar between the subject groups. DATA COLLECTION AND ANALYSIS: Threshold shifts relative to baseline were examined to determine whether they met criteria based on magnitudes of positive STS (shifts of > or =5, 10, 15, or 20 dB) and numbers of frequencies affected (shifts at > or =1, 2, or 3 adjacent frequencies) for data collected using approximately (1/6)-, (1/3)-, or (1/2)-octave steps. Thresholds were confirmed during monitoring sessions in which shifts were identified. Test performance was evaluated with receiver operating characteristic (ROC) curves developed using a surrogate "gold standard"; true positive (TP) rates were derived from the cisplatin-exposed group and false positive (FP) rates from the nonexposed, control group. Best STS definitions were identified that achieved the greatest areas under ROC curves or resulted in the highest TP rates for a fixed FP rate near 5%, chosen to minimize the number of patients incorrectly diagnosed with ototoxic hearing loss. RESULTS: At the early monitoring test, average threshold shifts differed only slightly across groups. Test-frequency step size did not affect performance, and changes at one or more frequencies yielded the best test performance. At the final monitoring test, average threshold shifts were +10.5 dB for the cisplatin group, compared with -0.2 dB for the control group. Compared with the (1/2)-octave step size used clinically, use of smaller frequency steps improved test performance for threshold shifts at > or =2 or > or =3 adjacent frequencies. Best overall test performance was achieved using a criterion cutoff of > or =10 dB threshold shift at > or =2 adjacent frequencies tested in (1/6)-octave steps. Best test performance for the (1/2)-octave step size was achieved for shifts > or =15 dB at one or more frequencies. CONCLUSIONS: An ototoxicity monitoring protocol that uses an individualized, one-octave range of frequencies tested in (1/6)-octave steps is quick to administer and has an acceptable FP rate. Similar test performance can be achieved using (1/3)-octave test frequencies, which further reduces monitoring test time.

Tinnitus onset rates from chemotherapeutic agents and ototoxic antibiotics: results of a large prospective study.

BACKGROUND AND PURPOSE: To report on the incidence and relative risk of tinnitus onset from a variety of drug therapies known to be ototoxic. Two main questions were asked: (1) What is the prevalence and incidence of tinnitus among patients treated with cisplatin, carboplatin, or ototoxic antibiotic therapies? (2) Do commonly reported treatment or subject factors confound or modify the incidence of tinnitus onset? DATA COLLECTION AND ANALYSIS: A prospective observational study design was used to evaluate occurrence of significant otologic changes in 488 veterans (962 ears) receiving chemotherapeutic agents (cisplatin, carboplatin), ototoxic antibiotics (primarily aminoglycoside), or nonototoxic drugs (control medications). A subset of 260 veterans lacking tinnitus prior to drug exposure was used to compare rates of tinnitus onset. Subjects were tested prior to, during, and following their treatment. Planned comparisons using logistic regression, analysis of variance (ANOVA), and chi(2) statistics were made among groups by the type of medication taken, age, presence of preexisting hearing loss, days on drug, and cumulative dose of drug. RESULTS: Baseline tinnitus rates were high (nearly 47%) relative to the general population of a similar age. Subjects with exposure to ototoxic medications had significantly increased risk for developing tinnitus. Those on chemotherapeutic agents were found to have the greatest risk. Cisplatin elevated the risk by 5.53 times while carboplatin increased the risk by 3.75 over nonototoxic control medications. Ototoxic antibiotics resulted in borderline risk (2.81) for new tinnitus. Contrary to other reports, we did not find that subject factors (increased age or pre-existing hearing loss) or treatment factors (days on drug or cumulative dose) contributed to rates of tinnitus onset during treatment. CONCLUSIONS: This large prospective study confirms that new tinnitus during treatment is associated with chemotherapy and with certain ototoxic antibiotic treatment. Cisplatin and carboplatin were found to be the most potent ototoxic agents causing tinnitus at much greater numbers than the other drugs studied. Implications for counseling and audiological resource allocation are discussed.

Factors affecting sensitivity of distortion-product otoacoustic emissions to ototoxic hearing loss.

OBJECTIVES: (1) To determine the ototoxicity detection rate (sensitivity) for distortion-product otoacoustic emissions (DPOAEs) testing in adults who received ototoxic medications and experienced pure-tone threshold changes during the course of treatment; (2) to determine the extent to which DPOAE sensitivity to ototoxicity depends on the type of drug administered (platinum or antibiotic), magnitude of ototoxic threshold shifts, pre-exposure pure-tone threshold, and DPOAE data; and (3) to build a model to predict DPOAE sensitivity. DESIGN: DPOAE and audiometric data were obtained as part of a prospective Veterans Affairs study investigating methods of ototoxicity monitoring. Data were analyzed from 90 ears of 53 subjects receiving ototoxic medications and showing significant hearing changes in at least one ear. Pure-tone threshold data were obtained at frequencies from 0.5 to 20 kHz, using 1/6-octave precision near the upper frequency limit of hearing. DPOAE data are reported for f2's from 0.8 to 8.0 kHz in 1/6-octave increments using primary levels (L1/L2) of 65/59 dB SPL and a primary frequency ratio (f2/f1) of 1.2. Test results were evaluated at various times during drug treatment to determine whether DPOAE level changes were associated with behavioral hearing changes. Univariate and multivariate analysis techniques were used to determine factors that affected DPOAE sensitivity to ototoxic damage. RESULTS: Of the 90 ears examined, 82 (91%) had DPOAEs that could be monitored for changes. Sixty-four of these 82 ears (78%) had DPOAEs that were reduced or absent following drug treatment. DPOAE sensitivity to ototoxicity was unrelated to the type of ototoxic drug administered. Rather, DPOAE sensitivity depended on the magnitude of postexposure hearing changes and on variables related to pre-exposure audiogram and DPOAE measurements. Behavioral hearing changes not detected by DPOAEs were small on average (<7 dB). DPOAE sensitivity was reduced in ears with poorer pre-exposure hearing, and in ears with measurable DPOAE frequencies limited to f2's below 2.5 kHz or more than one octave from the frequency region where hearing change occurred. Results of logistic regression modeling showed that DPOAEs present at f2's greater than 2.5 kHz were associated with the eventual success of ototoxicity monitoring with DPOAEs. However, independent variables examined could not explain differences in the relative timing of behavioral and DPOAE changes. A roughly equivalent proportion of ears experienced DPOAE changes before, during, or after behavioral hearing changes. CONCLUSIONS: DPOAEs are a useful screening tool for ototoxicity in adults with pre-exposure hearing loss, but are less sensitive compared with a behavioral test method that targets thresholds near the upper limit of a subject's audible frequency range. Ears successfully monitored for ototoxicity with DPOAEs are those with better pre-exposure hearing, greater postexposure hearing changes, and baseline DPOAEs near the highest behavioral test frequencies and present at high f2's. Results suggest that successful monitoring of ototoxicity with DPOAEs may be predicted clinically by assessing the measurable DPOAE f2 frequency range and its relation to the highest behavioral test frequencies.

NIDCD/VA hearing aid clinical trial and follow-up: background.

This report provides background regarding the Long Term Follow-Up of Patients in the NIDCD/VA Hearing Aid Clinical Trial study and serves as an introduction to the detailed reports that follow in this issue of Journal of the American Academy of Audiology. The authors investigated five- to seven-year benefit/satisfaction in participants from the original NIDCDNA Hearing Aid Clinical Trial. The new study was designed to investigate current use of the original study hearing aids, to compare changes in selected audiological measures, and to assess possible predictors of long-term hearing aid use. The outcome measures included estimates of speech intelligibility in quiet and noise, self-reported patterns of hearing aid usage, self-reported estimates of activity limitations and quality-of-life issues, estimates of hearing aid satisfaction, and self-reported hearing aid benefit. Overall, the short-term benefits of hearing aid use observed during the original trial were noted to persist in the long term.

Psychosocial correlates of hearing aid adjustment.

Despite considerable evidence regarding the detrimental effects of untreated hearing loss, there continues to be an underutilization of hearing aids by adults. The Long Term Follow-Up of Patients in the National Institute on Deafness and Other Communication Disorders/Veterans Affairs (NIDCD/VA) Hearing Aid Clinical Trial (Cooperative Studies Program [CSP] 418-A) provided the opportunity to compare a number of potential psychosocial influences and outcomes for hearing aid users and nonusers from the original CSP 418 study. The Communication Profile for the Hearing Impaired (CPHI) results provide compelling evidence of hearing aid benefit. Mean Communication Performance (CP) scores for hearing aid users on the Social, Work, and Home scales improved significantly from the original CSP 418 administration. For nonusers, there were no significant CPHI changes from the previous administration. Although hearing aid users and nonusers did not differ in optimism, this parameter was correlated with personal adjustment, measured via the CPHI. Hearing aid use was associated with the perception of major life events, such as illness, retirement, and so forth.

NIDCD/VA hearing aid clinical trial and follow-up: coupler and real-ear measurement.

A total of 190 individuals participated in a clinical visit during the Cooperative Studies Program (CSP) 418-A Long Term Follow-Up Study. Of this cohort, 158 participants were considered current hearing aid users, and 32 were non-hearing aid users. Of the current hearing aid users, 81 were still using their original 418 study devices, and 77 had acquired new hearing aids. Coupler and real ear measurements were completed on all available hearing aids. Results showed that study aids had remained relatively stable over the six years between CSP 418 and CSP 418-A. On average, these hearing aid wearers preferred use gain settings that were 6-9 dB less than current NAL-RP insertion gain targets. Mean real ear insertion gain (REIG) was comparable to the mean real ear insertion gain of the same participants in the original study, and users did not tend to increase gain as hearing decreased. Real ear saturation responses (RESR) remained unchanged. Loudness discomfort levels (LDL) obtained during 418-A were significantly lower than LDLs obtained on those same participants at both the initial and final visits in the previous study.

Speech-recognition performance after long-term hearing aid use.

Larson et al (2000) reported the findings of a multicenter, NIDCDNA clinical trial that compared hearing aid performance for three output limiting circuits in 360 adults with symmetrical sensorineural hearing loss. The current study was undertaken to examine long-term hearing aid benefit in this same group of participants following five to six years of hearing aid use. The speech-recognition portion of the follow-up study enrolled 108 participants from the original study, 85% of whom were current hearing aid users and 15% of whom had not worn hearing aids during the past month (nonusers). Recognition performance in sound field on the NU-6 (quiet at 62 dB SPL) and the CST (quiet at 74 dB SPL and with -3 and 3 dB signal-to-babble ratios [S/B] at 62 and 74 dB SPL) was measured unaided and aided whenever possible. Speech-recognition abilities decreased significantly since the original study. Speech-recognition decrements were observed regardless of the speech materials (NU-6 and CST), test condition (quiet and noise), S/B (-3 and 3 dB), or stimulus level (62 and 74 dB SPL). Despite decreases in speech recognition, hearing aid benefit remained largely unchanged since the original study; aided performance exceeded unaided performance regardless of presentation level or noise condition. As in the original study, the relations among stimulus level, S/B, and speech-recognition performance were complex.

Subjective measures of hearing aid benefit and satisfaction in the NIDCD/VA follow-up study.

Perceived benefit, satisfaction, and hearing aid use patterns were measured in a follow-up study to a large-scale multi-site clinical trial conducted in 1996-97. Measures included the Hearing Aid Status Questionnaire, the Profile of Hearing Aid Benefit, the Glasgow Hearing Aid Benefit Profile, the Satisfaction with Amplification in Daily Life, and the International Outcome Inventory for Hearing Aids. On the Profile of Hearing Aid Benefit, hearing aid users indicated more unaided difficulty in easy listening situations and less aided benefit in more difficult listening situations compared to the original study. Subjects who no longer used hearing aids indicated less difficulty in unaided situations. All measures indicated significant long-term subjective benefit and satisfaction with hearing aids. Although understanding speech in noise or in group situations continues to be problematic, subjects reported wearing their hearing aids almost all of the time in both easy and difficult listening situations.

Validation of the Home Hearing Test™.

BACKGROUND: The Home Hearing Test™ (HHT) is an automated pure-tone threshold test that obtains an air-conduction audiogram at five test frequencies. It was developed to provide increased access to hearing testing and support home telehealth programs. PURPOSE: The study was conducted as part of an audiology telehealth trial based at the U.S. Department of Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN. Air-conduction audiograms obtained by the HHT were compared to results obtained in the clinic. RESEARCH DESIGN: Prospective, repeated measures. STUDY SAMPLE: Twenty-eight participants, aged 44-88 yr (mean = 65) were recruited from the Nashville U.S. Department of Veterans Affairs audiology clinic. Participants were required to have a Windows personal computer in the home and were self-reported to be comfortable with using computers. Two participants had normal hearing and 26 had hearing loss of various severities and configurations. DATA COLLECTION AND ANALYSIS: Audiograms were obtained in the audiology clinic by experienced audiologists following standard clinical protocols. Participants were provided with a kit for installing HHT on their home computers. The HHT air-conduction audiogram is obtained with Automated Method for Testing Auditory Sensitivity (AMTAS(®)), described in previous publications. Threshold pairs (clinic versus HHT) were analyzed by determining distributions of threshold differences and absolute differences. These were compared to distributions of differences between manual threshold pairs obtained by two audiologists and AMTAS(®) versus manual threshold pairs obtained under laboratory conditions. RESULTS: Threshold differences (clinic versus HHT) were slightly larger than differences between thresholds obtained by two audiologists and AMTAS(®) versus manual threshold differences obtained under laboratory conditions. The differences were not statistically significant. CONCLUSIONS: HHT air-conduction audiograms agree well with audiograms obtained in the clinic. HHT is well suited to home telehealth applications and personal use.

Early detection of ototoxicity using 1/6th-octave steps.

The National Center for Rehabilitative Auditory Research has developed a protocol to provide early identification of ototoxicity for patients receiving ototoxic medications. The initial work involved patients with relatively good high-frequency hearing and resulted in the use of an individualized, sensitive frequency range separated by 1/6th-octave intervals. This protocol tested pure-tone frequencies at 1/6th-octave steps above 9 kHz, but only conventional audiometric frequencies were tested below 9 kHz. More recently, the testing protocol was expanded to include 1/6th-octave testing below 9 kHz. The primary question of interest was to determine whether adding 1/6th-octave test frequencies below 9 kHz would increase the ototoxicity detection rate for patients with poorer hearing. Results indicated 76 of the 210 (36.2%) ears that demonstrated initial ototoxic hearing change would have been missed or detected later if only conventional frequency testing was conducted.Therefore, for individuals with poorer hearing, expanding the use of the 1/6th-octave test protocol provides earlier identification of ototoxicity.

Real-world benefit from directional microphone hearing aids.

This article summarizes data from a 3-year, double-blinded study of directional hearing aid benefit. Ninety-four subjects in three hearing loss groups, all previous users of omnidirectional output-compression hearing aids, completed all aspects of the study. Participants were fit with new hearing aids for 1 month in a directional mode and 1 month in an omnidirectional mode. Following 1 month of use, subjects completed a number of objective and subjective measures of hearing aid outcome. Objective and subjective data were analyzed across hearing aid and hearing loss conditions. Subjects in all hearing loss groups exhibited better performance in the directional conditions for objective speech-in-noise measures; however, subjective data did not indicate a clear advantage for directional amplification. Results and clinical implications are discussed.

Coupler and real-ear measurement of hearing aid gain and output in the NIDCD/VA Hearing Aid Clinical Trial.

OBJECTIVE: Because the NIDCD/VA Hearing Aid Clinical Trial was conducted across eight clinical sites, rigorous control of the electroacoustic characteristics of the experimental devices was required. DESIGN: The parameters monitored included the gain and output of the approximately 720 hearing aids in the trial, measured both in the 2 cm3 coupler and in situ. Each measurement was repeated six times on each hearing aid across the 9-mo duration of the study to insure both the stability and the accuracy of the circuits under investigation. RESULTS: The gain data obtained in the coupler and in situ adequately demonstrated the stability of the instrument and the repeated measurements over time and across study sites. The output values produced by the experimental device also maintained acceptable constancy, both within and across treatment periods. CONCLUSIONS: These measurements reflected satisfactory stability and sufficient accuracy within the circuits to achieve the intended goals of the study.

A multi-center, double blind clinical trial comparing benefit from three commonly used hearing aid circuits.

OBJECTIVE: Although numerous studies have demonstrated that hearing aids provide significant benefit, carefully controlled, multi-center clinical trials have not been conducted. A multi-center clinical trial was conducted to compare the efficacy of three commonly used hearing aid circuits: peak clipping, compression limiting, and wide dynamic range compression. DESIGN: Patients (N = 360) with bilateral, sensorineural hearing loss were studied using a double blind, three-period, three-treatment crossover design. The patients were fit with each of three programmable hearing aid circuits. Outcome tests were administered in the unaided condition at baseline and then after 3 mo usage of each circuit, the tests were administered in both aided and unaided conditions. The outcome test battery included tests of speech recognition, sound quality and subjective scales of hearing aid benefit, including patients' overall rank-order rating of the three circuits. RESULTS: Each hearing aid circuit improved speech recognition markedly, with greater improvement observed for soft and conversationally loud speech in both quiet and noisy listening conditions. In addition, a significant reduction in the problems encountered in communication was observed. Some tests suggested that the two compression hearing aids provided a better listening experience than the peak clipping hearing aid. In the rank-order ratings, patients preferred the compression limiting hearing aid more frequently than the other two hearing aids. CONCLUSIONS: The three hearing aid circuits studied provide significant benefit both in quiet and in noisy listening situations. The two compression hearing aids appear to provide superior benefits compared to the linear circuit, although the differences between the hearing aids were smaller than the differences between unaided and aided conditions.