Clinical study of a digital vs an analogue hearing aid

Perceived Sound Quality of Hearing Aids With Varying Placements of Microphone and Receiver

PURPOSE

Perceived sound quality was variously compared between either no aiding or aiding with three models of hearing aid that varied the microphone position around the pinna, depth of the receiver in the auditory meatus, degree of meatal occlusion, and processing sophistication. The hearing aids were modern designs and commercially available at the time of testing.

METHOD

Binaural recordings of multichannel spatially separated speech and music excerpts were made in a manikin, either open ear or aided. Recordings were presented offline over wide-bandwidth, high-quality insert earphones. Participants listened to pairs of the recordings and made preference ratings both by clarity and externality (a proxy for "spaciousness"). Two separate groups of adults were tested, 20 with audiometrically normal hearing (NH) and 20 with mild-to-moderate sensorineural hearing loss (hearing impaired [HI]).

RESULTS

For ratings of speech clarity, the NH group expressed no preference between the open ear and a deeply inserted occluding aid, both of which were preferred to a low-pass filtered output of the same aid. For the music signal, a small preference emerged for the open-ear recording over that of the aid. For the HI group, clarity of the deeply inserted aid was similar to in-the-ear and behind-the-ear devices for speech, but worse for music. Ratings of spaciousness produced no clear result in either group, which can be attributed to study limitations and/or participant factors.

CONCLUSION

Based on clarity, a wide bandwidth, particularly to beyond 5 kHz generally and below 300 Hz for music, is desirable, independent of hearing aid design.

Hearing aid or "band aid"? Evaluating large scale hearing aid donation programmes in the Philippines

Objective: This study aimed to evaluate the effectiveness of two large scale hearing aid donation programmes in the Philippines.Design: Real ear measurements were made on all hearing aids, for comparison to NAL-RP prescription targets. Performance measures and the International Outcomes Inventory for Hearing Aids (IOI-HA) data was collected from a subsample of participants.Study sample: A total of 101 and 153 low socioeconomic status participants were sampled just after, or 6 months after receiving their hearing devices in each of the programmes evaluated, respectively.Results: Of the 189 hearing aids sampled at fitting, and the 195 hearing aids sampled at 6 months post fitting, less than 2% were within ±5dB of prescription target. At 6 months post fitting IOI-HA outcomes were essentially comparable to those described in the literature but were not a good predictor of fit to prescriptive target.Conclusions: Objective measures of hearing aid outcome were poor and showed no relationship to subjective outcome measures. Although able to fit large numbers in short time frames, to avoid a band aid solution, changes to such programmes should be made including: a focus on those with aidable hearing losses, increased opportunity for follow up care, and improved device quality.

Hearing Aids: A Review of What's New

OBJECTIVE: To review the recent innovations in hearing aid technology.

STUDY DESIGN: Review of the literature.

SETTING: Private tertiary referral otology/neurotology practice.

RESULTS: Recent innovations including digital signal processing (DSP), directional microphone technology, and open mold hearing aid fitting have resulted in improved satisfaction with current hearing aids.

CONCLUSION: Current hearing aid technology with its innovations better meet needs of individuals who are hard of hearing.

SIGNIFICANCE: The image commonly held of hearing aids by the general public is a negative one that can be improved with greater education.

Digital processing technology for bone-anchored hearing aids: randomised comparison of two devices in hearing aid users with mixed or conductive hearing loss

Objective:

This study compared the performance of two new bone-anchored hearing aids with older bone-anchored hearing aids that were not fully digital.

Methods:

Fourteen experienced bone-anchored hearing aid users participated in this cross-over study. Performance of their existing bone-anchored hearing aid was assessed using speech-in-noise testing and questionnaires. Participants were then fitted with either a Ponto Pro or a BP100 device. After four weeks of use with each new device, the same assessments were repeated.

Results:

Speech-in-noise testing for the 50 per cent signal-to-noise ratio (the ratio at which 50 per cent of responses were correct) showed no significant differences between the Ponto Pro and the BP100 devices (p = 0.1) However, both devices showed significant improvement compared with the participants' previous bone-anchored hearing aid devices (p < 0.001). There were no significant differences between the two new devices in the questionnaire data.

Conclusion:

Both fully digital bone-anchored hearing aids demonstrated superior speech processing compared with the previous generation of devices. There were no substantial differences between the two digital devices in either objective or subjective tests.

Ranking hearing aid input-output functions for understanding low-, conversational-, and high-level speech in multitalker babble

PURPOSE

To determine the rankings of 6 input-output functions for understanding low-level, conversational, and high-level speech in multitalker babble without manipulating volume control for listeners with normal hearing, flat sensorineural hearing loss, and mildly sloping sensorineural hearing loss.

METHOD

Peak clipping, compression limiting, and 4 wide dynamic range compression (WDRC) input-output functions were compared in a repeated-measure design. Interactions among the compression characteristics were minimized. Speech and babble were processed and recorded at 3 input levels: 45, 65, and 90 dB sound pressure level. Speech recognition of 3 groups of listeners (n = 6/group) was tested for speech processed by each input-output function and at each input level.

RESULTS

Input-output functions that made low-level speech audible and high-level speech less distorted by avoiding peak clipping or severe compression yielded higher speech recognition scores. These results are consistent with previous findings in the literature.

CONCLUSION

WDRCs with the low compression ratio region extended to a high input level or with a high compression limiting threshold were the best for speech recognition in babble when the hearing aid user cannot or does not want to manipulate the volume control. Future studies on subjective preferences of different input-output functions are needed.

Hearing aid satisfaction: what does research from the past 20 years say?

Hearing aid satisfaction is a pleasurable emotional experience as an outcome of an evaluation of performance. Many tools have been designed to measure the degree of satisfaction overall, or along the dimensions of cost, appearance, acoustic benefit, comfort, and service. Various studies have used these tools to examine the relationships between satisfaction and other factors. Findings are not always consistent across studies, but in general, hearing aid satisfaction has been found to be related to experience, expectation, personality and attitude, usage, type of hearing aids, sound quality, listening situations, and problems in hearing aid use. Inconsistent findings across studies and difficulties in evaluating the underlying relationships are probably caused by problems with the tools (eg, lack of validity) and the methods used to evaluate relationships (eg, correlation analyses evaluate association and not causal effect). Whether satisfaction changes over time and how service satisfaction contributes to device satisfaction are unclear. It is hoped that this review will help readers understand current satisfaction measures, how various factors affect satisfaction, and how the way satisfaction is measured may be improved to yield more reliable and valid data.

Reduced hearing, ownership, and use of hearing aids in elderly people in the UK--the MRC Trial of the Assessment and Management of Older People in the Community: a cross-sectional survey

BACKGROUND

Reduced hearing in elderly people is important because it is disabling and potentially treatable. We aimed to assess the prevalence of reduced hearing in elderly people and levels of ownership of hearing aids and use.

METHODS

We have done a cross-sectional survey of people aged at least 75 years in 106 family practices in the UK. We obtained self-reported data on hearing difficulties for 32,656 people and gave 14,877 a whispered voice test (response rate 78%).

FINDINGS

2537 (8%) of 32,656 participants reported a lot of difficulty hearing and 13,630 (42%) a little or a lot of difficulty. 3795 (26%) of 14877 participants who completed the whispered voice test (95% CI 23-29) failed the test, the proportion rising sharply with age. Following wax removal, 343 passed a retest, leaving 3452 (23%, 20-26) who failed the test, even after wax removal if present. 998 (46%) of 2180 people wearing a hearing aid at the time of testing failed the whispered voice test. More than half the people who failed the test did not own a hearing aid. 2200 (60%) of 3846 people who owned a hearing aid said they used it regularly. Level of use was strongly related to perceived benefit.

INTERPRETATION

Reduced hearing is common and provision of hearing aids inadequate in elderly people. Many people who own a hearing aid do not use it regularly, and even when wearing their aid many still have socially disabling levels of hearing loss. A major source of morbidity in elderly people could be alleviated by improvements in detection and management of reduced hearing.

A "virtual hearing aid" for comparing hearing aids in children: a double-blind crossover study

In this study, a "virtual hearing aid" was used to compare different types of hearing aids. A digital hearing aid (Oticon DigiFocus Compact) and an analogue, automatic reference hearing aid were compared in a group of 17 schoolchildren (median age: 10 years) with moderate to severe, symmetrical, sensorineural hearing loss. Differences in performance were assessed using routine diagnostic methods (speech recognition performance tests, loudness scaling), subjective assessments (questionnaires) and the "virtual hearing aid". Guaranteeing double-blind testing conditions, the "virtual hearing aid" offers the possibility to directly compare individual in-situ recordings of different hearing aids. In contrast to the clear subjective preferences for the digital hearing aid, we could not obtain any significant results with routine diagnostic methods. Using the "virtual hearing aid", the subjective comparison and speech recognition performance tasks yielded significant differences. The "virtual hearing aid" proved to be suitable for directly comparing different hearing aids under double-blind testing conditions.