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.     

Comparison of two methods for estimating the sensation level of amplified speech.

Several methods have been proposed to estimate the sensation level (SL) at which children receive amplified speech from their hearing aids. The present study compared the SL estimates obtained with two such methods: (1) a sound field aided audiogram approach, and (2) an electroacoustic approach that incorporated the use of a probe tube microphone system (Seewald, Ross, & Stelmachowicz, 1987). Sound field aided thresholds were obtained for 13 hearing-impaired subjects at eight audiometric frequencies. For the electroacoustic approach, in situ thresholds were obtained using a button-type hearing aid receiver attached to a custom earmold. Real ear aided responses were measured using a 70 dB RMS speech-weighted composite noise signal (Frye, 1986). A comparison of the frequency-specific SL estimates derived from the two different methods revealed that the sound field aided audiogram approach yielded higher SL estimates for 74% of the individual comparisons. A detailed analysis of the findings obtained from two subjects suggested that when the results of the two methods did not agree, the differences were due to an interaction between signal level and the unique input/output characteristics of the subjects' hearing aids. A precautionary measure is suggested for those who wish to use sound field aided threshold data to estimate the SLs at which children receive amplified conversational speech.     

Verification of Improved Patient Outcomes With a Partially Implantable Hearing Aid,The SOUNDTEC Direct Hearing System

Introduction Partially implantable hearing devices have been developed to address some of the user‐perceived shortcomings of standard amplification systems. Partially implantable devices are purported to provide improved sound quality as a result of decreased occlusion, decreased feedback, and enhanced clarity resulting from increased high‐frequency gain. Such improvements may result in greater user satisfaction. To justify selection of a partially implantable device and undergoing a minor surgical procedure, verification techniques must be used to document user improvement or increased satisfaction over conventional amplification. Objective To evaluate patient satisfaction with the SOUNDTEC direct hearing system. Study Design Within‐subjects repeated measures design. Methods Objective and subjective evaluation pre‐ and post‐implantation with the SOUNDTEC device. Verification techniques included tonal functional gain measures with traditional amplification and the SOUNDTEC device, word recognition in quiet (NU‐6) and in noise (SPIN), the Abbreviated Profile of Hearing Aid Benefit (APHAB), and the Hough Ear Institute Profile (HEIP). Results Although there was no significant difference between optimal traditional amplification and the SOUNDTEC device for speech perception measures, the SOUNDTEC device yielded statistically significant increased high‐frequency functional gain. Subjective reports indicated that the SOUNDTEC device provides a cleaner, more natural sound without feedback than traditional amplification. Conclusions Partially implantable hearing aids may address some of the limitations of traditional amplification systems.     

Improvements in speech intelligibility in quiet and in noise produced by two-channel compression hearing aids

Eight subjects suffering from bilateral sensorineural hearing losses with recruitment were fitted binaurally with two-channel compression hearing aids, worn behind the ear. After they had worn the aids for some time, measures of speech intelligibility were compared for two conditions: listening unaided, and listening aided. the dynamic range for speech, defined as the difference in level between the speech reception threshold in quiet and the highest comfortable level for speech, was substantially increased in the aided condition for seven of the eight subjects (the exception was a subject with almost normal low-frequency hearing). Speech reception thresholds were also measured in two levels of background noise ('babble'), 60 and 75 dB SPL. Seven of the eight subjects showed a reduced speech reception threshold (i.e. an improvement) in the aided condition for at least one of the two noise levels, although the size of the improvement differed considerably from one subject to another. The subjects were also given a battery of psycho-acoustical tests in an attempt to better characterise their hearing loss, and to gain more insight into individual differences. Results of measurements of frequency selectivity, frequency discrimination, temporal acuity and temporal masking are described and related to the measures of speech intelligibility.     

Comparison of hearing aids over the 20th century

OBJECTIVE: To measure hearing aid performance using circuitry representative of the major eras of technological advancement during the 20th century. DESIGN: Twenty subjects with audiometric profiles consistent with hearing aid candidacy were fit with each of seven hearing aids. No directional microphones were used and binaural benefit was not assessed. Each hearing aid was fit to the strategy or fitting scheme of the era, or that which was intended by the presenting manufacturer. Electroacoustic and/or real ear measures of gain, output, bandwidth, and distortion were obtained. Objective outcome measures assessing speech perception in backgrounds of noise were obtained. Subjective outcome measures of sound quality and ease of listening were obtained in the laboratory and in real life settings. RESULTS: Electroacoustic and real ear measures indicate that gain and bandwidth have increased, and output and distortion have decreased with current electronic aids. Speech perception ability across the different outcome measures showed significantly poorer performance with the body and linear hearing aids when input levels were high; when input levels were low, outcome measures with hearing aids using a dynamic range compression were not negatively affected. At the most adverse signal to noise ratios, none of the hearing aids was shown to be superior. Measured bandwidth did not correlate highly with speech perception ability for any of the objective outcome measures used. For the subjective measures of sound quality done in a blinded manner, no significant differences were found across different listening situations for current hearing aids. CONCLUSIONS: The two most important factors for aided speech perception appear to be the audibility and distortion of the signal. No current compression scheme proved superior with the outcome measures used in this investigation.     

Evaluating the benefit of speech recoding hearing aids in children

Children with significant high-frequency hearing loss may be difficult to fit with hearing aids using conventional amplification. Frequency-lowering hearing aids using dynamic speech recoding (DSR) technology have been proposed as a possible means to achieve full speech audibility. The current study investigated 78 children from ages 1.3 to 21.6 years (M = 10.6 years) who wore DSR hearing aids. These hearing aids provided significant improvements in pure-tone average (PTA; mean improvement for the aided versus unaided condition of 49 dB) and high-frequency PTA (mean improvement for the aided versus unaided condition of 56 dB). A subgroup of 19 children were previous users of conventional hearing aids. These participants demonstrated a mean improvement of 11 dB in PTA and 12.5% in word recognition scores for DSR versus conventional amplification. However, DSR hearing aids required repair 3 times as often as conventional hearing aids. The greatest benefit was observed in children whose word recognition scores were poorest using conventional hearing aids.     

Comprehensive hearing aid assessment in adults with bilateral severe-profound sensorineural hearing loss who present for Cochlear implant evaluation

PurposeTo comprehensively assess and describe functional auditory performance in a group of adults with bilateral, moderate sloping to profound sensorineural hearing loss who were dissatisfied users of well-fit bilateral hearing aids and presented for Cochlear implant evaluation. Participants were evaluated with bilateral hearing aids and after six months of bimodal (Cochlear implant and a contralateral hearing aid) hearing experience with a Cochlear implant and contralateral hearing aid.MethodsStudy participants were assessed using pure tone audiometry, aided speech understanding in quiet (CNC words) and in noise (AzBio sentences at +10 and +5 dB SNR) in the sound field with unilateral and bilateral hearing aids fit to target. Participants completed subjective scales of quality of life, (Health Utilities Index Mark 3), hearing disability, (Speech, Spatial and Qualities of Hearing Scale) and a device use satisfaction scale. Participants ≥55 years were administered the Montreal Cognitive Assessment screening tool. One-hundred enrolled individuals completed baseline evaluations.ResultsAided bilateral mean speech understanding scores were 28% for CNC words and 31%, and 17% for AzBio sentences at a +10 dB, and +5 dB SNR, respectively. Mean scale ratings were 0.46 for overall quality of life and 3.19 for functional hearing ability. Ninety percent of participants reported dissatisfaction with overall hearing performance.ConclusionsEvaluation results, including functional performance metrics quantifying the deleterious effects of hearing loss for overall wellbeing, underscore that bilateral hearing aids are not an effective treatment for individuals with bilateral, moderate sloping to profound sensorineural hearing loss. Individuals with this degree of hearing impairment, who demonstrate poor aided speech understanding and dissatisfaction with hearing abilities in everyday life, require timely referral to a Cochlear implant clinic for further evaluation.     

助听器音频补偿效果与构音清晰度的相关研究

目的 通过分析配戴助听器儿童的音频补偿效果与构音清晰度得分的相关关系,为听障儿童的听觉言语综合康复提供理论依据.方法 对43名配戴助听器儿童进行助听后的声场测试以及构音语音能力主观评估,并进行统计学分析.结果 助听器音频补偿效果越差,听障儿童的构音清晰度得分越低.结论 助听器验配与优化只是补偿听力的完成,进行听觉康复训练和言语矫治是充分发挥助听器作用的必要手段,也是提高听障儿童构音清晰度的前提和基础.     

One year follow-up of users of a digital hearing aid.

A follow-up study has been performed on 29 of 33 original subjects who participated in a clinical trial of the digital hearing aid Oticon DigiFocus. The follow-up was performed after one year's use. Use of hearing instruments was assessed and questionnaires on hearing aid benefit, and hearing impairment and handicap were administered. Ratings of sound quality and measurements of speech recognition in noise were also performed. The results indicated almost doubled daily use of hearing aids as compared to that stated for the subjects' previous analogue aids one year earlier. Further, we found statistically significant improvements in speech recognition in noise one year post-fitting as compared to after one month. Other test results were essentially unchanged over time: no measure showed a significantly poorer rating or performance.     

Clinical Results of Hearing Aid with Noise-Level-Controlled Selective Amplification

We have developed a hearing aid which reduces the low-frequency energy of the input sound according to the input noise level and the spectrum of the environmental noise. The results of speech discrimination tests using speech in noise in 70 hearing-impaired subjects showed improvement in word discrimination scores in noise of over 15% for 50 of 53 subjects with sensorineural hearing loss. This group of hearing-impaired patients was subdivided into categories according to (a) audiogram type [flat, sloping (i.e. gradual high-frequency loss) and abruptly falling (steep high-frequency slope)]; (b) degree of hearing loss (less than or more than 50 dB average loss) and (c) etiology (familial deafness, presbyacusis). Results on 17 subjects with conductive or mixed hearing impairments showed no improvement, but expressed a preference for this system. The subject reported that the sound was more natural and quiet compared with the conventional AGC hearing aids.     

Clinical results of hearing aid with noise-level-controlled selective amplification

We have developed a hearing aid which reduces the low-frequency energy of the input sound according to the input noise level and the spectrum of the environmental noise. The results of speech discrimination tests using speech in noise in 70 hearing-impaired subjects showed improvement in word discrimination scores in noise of over 15% for 50 of 53 subjects with sensorineural hearing loss. This group of hearing-impaired patients was subdivided into categories according to (a) audiogram type [flat, sloping (i.e. gradual high-frequency loss) and abruptly falling (steep high-frequency slope)]; (b) degree of hearing loss (less than or more than 50 dB average loss) and (c) etiology (familial deafness, presbyacusis). Results on 17 subjects with conductive or mixed hearing impairments showed no improvement, but expressed a preference for this system. The subject reported that the sound was more natural and quiet compared with the conventional AGC hearing aids.     

A bone-anchored hearing aid for patients with pure sensorineural hearing impairment: a pilot study

This pilot study assesses the potential benefits of an optimized bone-anchored hearing aid (BAHA) for patients with a mild to moderate pure sensorineural high frequency hearing impairment. The evaluation was conducted with eight first-time hearing aid users by means of psycho-acoustic sound field measurements and a questionnaire on subjective experience; all of the patients benefited from the BAHA. On average, the eight patients showed improvement in PTA threshold of 3.4 dB and in speech intelligibility in noise of 14%. Seven of the subjects, also fitted with present standard air conduction hearing aids (ACHA) found the ACHA thresholds to be improved more than the BAHA ones. In speech tests, the ACHA was only slightly better; these patients chose between their different hearing aids according to the sound environment. Although the BAHA was preferred for wearing and sound comfort, it cannot be used as the sole aid for patients with pure sensorineural impairment.     

Acclimatization in first-time hearing aid users using three different fitting protocols

OBJECTIVE: To study auditory acclimatization and outcome in first time hearing aid users fitted with state of the art hearing aids as a function of different hearing aid fitting protocols. METHODS: Twenty-eight adult subjects participated in the study. Each subject was assigned to one of three study groups (named audiologist driven, AD; patient driven, PD; set-to-target, STT according to the fitting protocol used) and fitted with digital hearing aids (Bernafon Symbio). Speech recognition scores were measured in aided and unaided conditions over a 6-month period. RESULTS: Five subjects (three from the PD-group, two from the STT group) decided to withdraw from the study during the 6-month-study period, leaving a total of 23 complete data sets for analysis. Aided speech understanding increased significantly over this time period in all three groups. However, average hearing aid insertion gain changes were small over the same period. There were no statistically significant differences in aided or unaided speech recognition scores between the three groups after 2 weeks or after 6 months. On average, twice as many fine tunings of the hearing aids were requested by the patients in the AD and the STT group than in the PD group and subjects in the AD and STT group used their hearing aids approximately twice as much as subjects in the PD group. CONCLUSIONS: The substantial increase in speech intelligibility without significant changes of the insertion gain of the hearing aids over a 6-month period in all three groups suggests a significant acclimatization effect. Although the speech recognition with hearing aids did not differ significantly among the three study groups after 6 months, the lower average wearing time and the higher number of withdrawals from the study in the PD group suggest that the patients' needs are not adequately met. In terms of aided speech recognition scores and hearing aid wearing time the STT group and the AD group were very similar. However, comments of the patients and the higher rate of withdrawals in the STT group suggest an over-all advantage for the AD fitting protocol.     

Evaluation of a dual-channel full dynamic range compression system for people with sensorineural hearing loss.

This article describes an evaluation of an in the ear hearing aid, which applies fast-acting full dynamic range compression independently in two frequency bands. This can compensate for the loudness recruitment typically associated with sensorineural hearing loss. The crossover frequency between the two bands and the gain and compression ratio in each band are programmable to suit the individual patient. Twenty subjects with moderate sensorineural hearing loss were tested in a counterbalanced order using the aid programmed as a linear amplifier (condition L) and as a two-band compressor (condition C). All subjects were fitted binaurally. Subjects were also tested without hearing aids (condition U) and using the hearing aids that they normally wore (condition Own). Speech intelligibility was measured in quiet at three sound levels (50, 65, and 80 dB SPL), and speech reception thresholds (SRTs) in 12-talker babble were measured under monaurally and binaurally aided conditions, with the speech and babble both coincident and spatially separated. In condition C, speech intelligibility in quiet was high at all sound levels. Speech intelligibility at the two lower levels decreased in condition L, and decreased still further in conditions Own and U. Condition C gave, on average, better speech intelligibility in babble (lower SRTs) than conditions L, Own, or U. The advantage of condition C over condition L varied across subjects and was correlated with the dynamic range for tones at high frequencies; small dynamic ranges were associated with greater benefit from compression. A significant advantage for binaural aiding was found both when the speech and noise were spatially separated and when they were coincident. The binaural advantage was similar for the C and L conditions, indicating that the independent compression at the two ears did not adversely affect the use of binaural cues. Questionnaires on the subjects' experiences with the aids in everyday life indicated that they generally preferred condition C over condition L.     

Clinical study of Widex Senso on first-time hearing aid users.

Using psychoacoustic tests and questionnaires, the aim of this study was to clinically test Widex Senso (WS) versus analogue hearing aids on 200 first-time wearers. Half of the participants were selected at random for fitting with the behind-the-ear model (WS C8) or the in-the-canal model (WS CX). On a group basis, WS was found to provide more benefit than a palette of 29 analogue, modern hearing aid models from 10 manufacturers. Only 3 of 100 subjects changed from WS to another hearing aid. On average, the abbreviated profile of hearing aid benefit (APHAB) (Cox & Alexander, 1995) demonstrated superior performance for WS, i.e. no conflict existed between high comfort and high speech recognition. Median aided frequency-modulated tone thresholds in the sound field were better than 25 dB HL at frequencies up to 4 kHz inclusive. A distinct mean aided improvement of speech threshold in competing speech of 2.5 dB was found in both groups.     

Tinnitus in elderly patients

Tinnitus is the perceived sensation of sound in the absence of acoustic stimulation. Spontaneous idiopathic tinnitus is a significant interdisciplinary therapeutic problem. In elderly patients it most frequently coexists with sensorineural hearing loss. The chief idea of tinnitus retraining therapy (TRT) in treatment of chronic tinnitus consists of following strategies: low level and broad band noise surroundings, diversion of the attention to other things and psychological counseling and therapy. The purpose of this study was to verify the benefits and ramifications of tinnitus retraining therapy in elderly patients suffering from chronic tinnitus with sensorineural hearing loss. Methods 30 subjects aged 65-90 years suffering from chronic tinnitus and sensorineural hearing loss were questioned about features of the tinnitus using a set of standardised questions. All of them were fitted with modern digital hearing aids and questioned about subjective hearing results after a month of follow-up. Main result 24 of the patients declared to have had considerable improvement in tolerance of the tinnitus. Main conclusion Fitting with hearing aids is an effective way of treatment in the majority of elderly patients with chronic tinnitus. The effectiveness of supplying elderly patients with hearing aids for tinnitus management depended in our group of patients on whether the patient had good speech understanding prior to fitting with hearing aids (speech discrimination score below and above 80%).     

Hearing aid saturation and aided loudness discomfort.

Clinical measurements of the loudness discomfort level (LDL) are generally performed while the subject listens to a particular stimulus presented from an audiometer through headphones (AUD-HP). The assumption in clinical practice has been that the sound pressure level (SPL) corresponding to the sensation of loudness discomfort under AUD-HP conditions will be the same as the corresponding to LDL with the hearing aid. This assumption ignores the fact that the distortion produced by a saturating hearing aid could have an influence on the sensation of loudness. To examine these issues, 5 hearing-impaired subjects were each fit with four linear hearing aids, each having a different saturation sound pressure level (SSPL90). Probe-tube microphone measurements of ear canal SPL at LDL were made while the subjects listened to continuous discourse in quiet under aided and AUD-HP conditions. Also using continuous discourse, real-ear coherence measures were made at various output sound pressure levels near LDL. All four hearing aid types produced mean LDLs that were lower than those obtained under AUD-HP conditions. Those hearing aids with higher SSPL90 produced significantly higher LDLs than hearing aids with lower SSPL90. A significant negative correlation was found between real-ear SPL and real-ear coherence. Quality judgments made at LDL indicated that sound quality of hearing aids with higher SSPL90 was preferred to that of hearing aids with lower SSPL90. Possible fitting implications regarding the setting of SSPL90 from AUD-HP LDL measures are discussed.     

Objective and subjective hearing aid assessment outcomes

PURPOSE: To determine whether specific sentence recognition assessments were sensitive enough to serve as objective outcome measurements that document subjective improvements in speech understanding with hearing aids. METHOD: The Revised Speech Perception in Noise test (R-SPIN; R. C. Bilger, J. M. Nuetzel, W. M. Rabinowitz, & C. Rzeczkowski, 1984), the Hearing in Noise Test (HINT; M. Nilsson, S. D. Soli, & J. A. Sullivan, 1994), and the Quick Speech-in-Noise test (QuickSIN; Etymotic Research, 2001; M. C. Killion, P. A. Niquette, G. I. Gudmundsen, L. J. Revit, & S. Banerjee, 2004) were administered to 21 hearing aid users to determine whether the tests could adequately document improvements in speech understanding with hearing aids compared with the research participants' self-assessments of their own performance. Comparisons were made between unaided and aided performance on these sentence tests and on the Hearing Aid Performance Inventory (HAPI; B. E. Walden, M. Demorest, & E. Hepler, 1984). RESULTS: The R-SPIN, the HINT Quiet threshold, and the QuickSIN signal-to-noise ratio (SNR) loss were the most sensitive of the sentence recognition tests to objectively assess improvements in speech perception performance with hearing aids. Comparisons among the subjective and objective outcome measures documented that HAPI ratings improved as performance on the R-SPIN, the HINT Quiet threshold, and the QuickSIN SNR loss improved. CONCLUSIONS: Objective documentation of subjective impressions is essential for determining the efficacy of treatment outcomes in hearing aid fitting. The findings reported here more clearly define the relationship between objective and subjective outcome measures in an attempt to better define true hearing aid benefit.     

Relative benefits of linear analogue and advanced digital hearing aids

Speech recognition performance and self-reported benefitfrom linear analogue and advanced (digital) hearing aidswere compared in 100 first-time hearing aid users withmild-to-moderate sensorineural hearing loss fitted monaurally with a behind-the-ear (BTE) hearing aid in a single-blind randomized crossover trial. Subjects usedeach aid for 5 weeks in turn, with aid order balancedacross subjects. Three alternative models of digital hearing aid were assigned to subjects according to a balanceddesign. Aid type was disguised to keep subjects blind within practical limitations. Aided speech recognition performance in noise was measured at speech levels of 65 and 75 dB at a speech-to-noise ratio (SNR) of _2 dB forclosed sets of single words. Self-rated benefit was measured using the Abbreviated Profile of Hearing Aid Benefit (APHAB) and the Glasgow Hearing Aid Benefit Profile (GHABP). Quality of life, hearing aid use and user preferences were also assessed. Speech recognition scores with the digital aids were significantly better at 75 dB than with the analogue aids. Self-reported benefit (APHAB, GHABP) and improvement in quality of life were generally not significantly different between analogue and digital aids, although aversiveness measured with the APHAB was significantly lower with digital aids,and satisfaction measured with the GHABP was greater. The digital aids were preferred significantly more often than the analogue aids, with 61 subjects choosing their digital aid, 26 choosing the analogue aid, and nine being equivocal. Overall, this study shows advantages for advanced digital over simple linear analogue aids interms of both objective and subjective outcomes, although average differences are not large.     

Cochlear implant in patients with residual hearing

Objective: The postoperative speech perception abilities of severely hearing-impaired patients with multi-channel cochlear implant were compared with preoperative speech perception performance with conventional hearing aids. Methods: Cochlear implantation was performed in six severely to profoundly hearing-impaired patients. They had unaided pure-tone thresholds of 70–100-dB HL and aided thresholds of 35–90-dB HL in the better ear, but were not able to perceive speech sounds well with hearing aids. Results: Postoperatively, all the patients had significantly improved speech perception performance, exceeded the average skills of profoundly deaf cochlear implant users, and were able to communicate without writing. Conclusion: These results imply that cochlear implant may be indicated for severely to profoundly deaf subjects, if they receive little or no benefit from conventional hearing aids.