[Show abstract][Hide abstract] ABSTRACT: Inability to understand speech in noise has been cited repeatedly as the principal complaint of hearing aid users. While data exist documenting the benefit provided by hearing aids with directional microphones when listening to speech in noise, little work has been done to develop a standard clinical protocol for fitting these hearing aids. Our goal was to evaluate a clinical measure of the acoustic directivity of a directional hearing aid, including its association with a test of speech perception in noise.
The performance of two commercially available directional behind-the-ear (BTE) hearing aids was evaluated using the Hearing in Noise Test (HINT) and the Real Ear Aided Response (REAR) on 24 adult participants with symmetric, mild to moderately severe, sensorineural hearing loss. The HINT was conducted with the speech signal presented from 0 degrees and the noise from 180 degrees and either 135 degrees or 225 degrees, depending on the ear tested. REAR was measured at the above three angles using swept pure tones, and these measures were used to compute in situ directivity for each subject and hearing aid.
Directional benefit for the HINT was greatest when noise was presented from the azimuth of the published polar diagram null of a given hearing aid in its directional mode (180 or 135/225 degrees). The only significant correlation between HINT and REAR results, however, was found when the noise source was at 180 degrees. These results confirm the validity of using real ear measures as a way to assess directionality in situ, but also indicate the complexity of predicting perceptual benefit from them. These data suggest that factors beyond acoustic directionality may contribute to improvement in speech perception in noise when such improvements are found.
Ear and Hearing 05/2004; 25(2):147-58. · 3.26 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to measure hearing aid satisfaction and usage for extended periods of time, up to 2 yr after hearing aid delivery, to determine whether longitudinal changes occur in the elderly for these outcome measures.
A longitudinal study of hearing aid satisfaction and usage was performed in a group comprised of 134 elderly hearing aid wearers with these outcome measures obtained at 1, 6, and 12 mo postfit. A total of 49 of the original 134 elderly returned 2 yr after hearing aid delivery to complete the satisfaction and usage measures again. Multiple self-report measures of hearing aid satisfaction and hearing aid usage were obtained at each follow-up session.
Most between-interval comparisons of the various measures of satisfaction and usage failed to reveal significant changes over time. However, some significant changes were observed in both satisfaction and usage. When such changes occurred, they were always in a direction that suggested a decrease in satisfaction or usage over time. Correlations across various postfit interval pairs were found to be positive, statistically significant, and moderate to strong in strength for all measures of satisfaction and usage.
Although there were slight declines in hearing aid usage and satisfaction over time, measures of hearing aid satisfaction obtained at 1 mo postfit and of hearing aid usage obtained at 6 mo postfit are generally stable for up to 2 yr after hearing aid delivery.
Ear and Hearing 11/2002; 23(5):428-38. · 3.26 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to compare the results of two measures of hearing aid satisfaction, an indirect measure (Satisfaction with Amplification in Daily Living, SADL; Cox & Alexander, 1999) and a direct measure (an expanded version of the MarkeTrak-IV survey; Kochkin, 1996), in a group of elderly hearing aid wearers.
A total of 43 elderly hearing aid wearers completed both satisfaction measures (order counterbalanced across wearers) after 1 mo of wearing 2-channel wide dynamic range compression (WDRC) in-the-canal (ITC) hearing aids. A correlational research design was employed.
The elderly hearing aid wearers in this study yielded results on each measure of hearing aid satisfaction that were generally consistent with those found previously in larger groups of similar samples. The correlation between each measure of satisfaction (r = 0.75) was positive, moderately strong, and significant (p < 0.01) for the global scores of the SADL and MarkeTrak-IV scales.
Although different approaches to the measurement of satisfaction were followed in the development of the SADL (indirect approach) and the MarkeTrak-IV (direct measurement) scales, similar results were obtained with each scale. The 15-item SADL instrument, however, is much shorter than the MarkeTrak-IV instrument and, as a result, is more efficient to administer clinically.
Ear and Hearing 10/2002; 23(5):422-7. · 3.26 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study reports the results of a large number of hearing-aid benefit measures obtained from 134 elderly hearing-aid wearers during the first year of hearing-aid usage. Benefit measures were obtained after 1 month, 6 months, and 1 year of hearing-aid use by all participants. In addition, follow-up measurements of hearing-aid benefit were performed on 49 of these same hearing-aid wearers following 2 years of hearing-aid use. All participants in this study were fit binaurally with identical full-concha in-the-ear (ITE) hearing aids that used linear Class-D amplifiers with output-limiting compression. Benefit measures included several objective tests of speech recognition, as well as the subjective self-report scales of the Hearing Aid Performance Inventory (HAPI; B. E. Walden, M. E. Demorest, & E. L. Hepler) and the Hearing Handicap Inventory for the Elderly (HHIE; I. Ventry & B. Weinstein, 1982). Although group means changed only slightly over time for all of the benefit measures, significant differences were observed for some of the benefit measures, especially among the subjective, self-report measures of benefit. In almost all of the cases exhibiting significant changes, performance was significantly worse (less benefit) at both the 6-month and 1-year post-fit interval compared to the measurements at 1 month post-fit. In general, the individual data from the 134 participants who were represented in the 1-year data set were consistent with the trends in the group data described above. Regarding longer term changes in benefit following 2 years of hearing-aid use, minimal changes were again observed. In all, there was little evidence for acclimatization of hearing-aid benefit in this study in either the group or the individual data.
Journal of Speech Language and Hearing Research 08/2002; 45(4):772-82. · 1.97 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study reports the results of a large number of hearing-aid outcome measures obtained from 173 elderly hearing-aid wearers following one month of hearing-aid use. All participants in this study were fit binaurally with identical full-concha in-the-ear (ITE) hearing aids having linear Class-D amplifiers with output-limiting compression. Outcome measures included several measures of speech recognition, as well as several self-report measures of hearing-aid performance, benefit, satisfaction, and use. Comparison of mean data from this sample of hearing-aid wearers to other larger sets of data, obtained previously for several of these measures of hearing-aid outcome evaluated in isolation, indicated that the participants in this study were representative of the participants in other larger-scale studies. Subsequent principal-components factor analysis of the data from this study indicated that there were seven distinct dimensions of hearing-aid outcome. Attempts to document the effectiveness and efficacy of hearing aids for elderly persons with impaired hearing will be most complete when assessing performance along all seven dimensions of hearing-aid outcome. Clinically efficient procedures for doing so are discussed.
Journal of Speech Language and Hearing Research 07/2001; 44(3):469-86. · 1.97 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study reports the prescribed, clinician-fit, coupler gain and the user-adjusted, as-worn coupler gain measured in 55 adults ranging in age from 60 to 83 years (M = 72.2 years). All participants were fit with linear, output-limiting compression, Class D circuits in full-concha, in-the-ear (ITE) shells. The NAL-R prescription rationale was used to generate target real-ear insertion gain (REIG) and coupler gain values. The clinician-fit gain was measured when the hearing aid was dispensed initially and was found to be a close match to the prescribed coupler gain. Both clinician-fit and as-worn gain were measured subsequently at approximately 2 weeks, 1 month, 6 months, and 1 year after the initial fitting. As-worn gain was measured as soon as the participant returned to the clinic for one of the follow-up visits by simply removing the hearing aids and placing them in the test chamber without any adjustments in volume control. At each follow-up session, the clinician then inspected the hearing aids, evaluated the instruments electroacoustically, readjusted the volume control to the setting used to match the prescribed gain in the initial fit, and measured the clinician-fit coupler gain once again. Results revealed that, despite the capability of the hearing aid to achieve coupler gain that is a close match to the prescribed gain, these users consistently selected as-worn gain that was generally 6-9 dB below that prescribed by the NAL-R formula. Of this 6-9 dB disparity, however, as much as 3-6 dB could be due to binaural summation effects not taken into consideration in the NAL-R prescriptive formula. In addition, 5.4% of the time, the hearing aids were found to be in less than ideal operating condition when removed for the as-worn gain measurements (e.g., weak or dead battery, cerumen occluding the sound bore, telecoil switch in the incorrect position).
Journal of Speech Language and Hearing Research 09/2000; 43(4):879-92. · 1.97 Impact Factor