Article

Hearing aids with external receivers: Can they offer power and cosmetics?

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

An abstract is unavailable. This article is available as HTML full text and PDF.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... With RITA instruments, sound must be conducted via tubing from the receiver within the instrument to the ear canal. This transfer will cause resonance effects within the output that creates peaks in the frequency response (Hoen and Fabry, 2007). Peaks in the frequency response can be especially troublesome to those with sensorineural hearing loss due to the upward spread of masking (Jerger et al, 1960; Trees and Turner, 1986; Gagne, 1988). ...
... In fact, van Buuren et al (1996) demonstrated that embedded peaks within the overall frequency response degraded speech intelligibility in listeners with impaired hearing. Conversely, RITE hearing instruments deliver sound directly from the receiver within the ear canal and tend to have a smoother frequency response (Hoen and Fabry, 2007, Hallenbeck and Groth, 2008; Kuk and Baekgaard, 2008) and broader bandwidth than RITA hearing instruments (Kuk and Baekgaard, 2008). Reducing peaks within the frequency response should reduce upward spread of masking effects, thereby potentially improving speech intelligibility and sound quality as the overall smoothness of the frequency response of a hearing instrument is correlated with subjective sound quality (van Buuren et al, 1996; Hoen and Fabry, 2007). ...
... Conversely, RITE hearing instruments deliver sound directly from the receiver within the ear canal and tend to have a smoother frequency response (Hoen and Fabry, 2007, Hallenbeck and Groth, 2008; Kuk and Baekgaard, 2008) and broader bandwidth than RITA hearing instruments (Kuk and Baekgaard, 2008). Reducing peaks within the frequency response should reduce upward spread of masking effects, thereby potentially improving speech intelligibility and sound quality as the overall smoothness of the frequency response of a hearing instrument is correlated with subjective sound quality (van Buuren et al, 1996; Hoen and Fabry, 2007). Consequently, RITE instruments may be preferred over RITA instruments for some listeners due to improved speech intelligibility and improved subjective sound quality associated with smoother, broader frequency responses. ...
Article
Full-text available
Open canal hearing instruments differ in method of sound delivery to the ear canal, distance between the microphone and the receiver, and physical size of the devices. Moreover, RITA (receiver in the aid) and RITE (receiver in the ear) hearing instruments may also differ in terms of retention and comfort as well as ease of use and care for certain individuals. What remains unclear, however, is if any or all of the abovementioned factors contribute to hearing aid outcome. To determine the effect of receiver location on performance and/or preference of listeners using open canal hearing instruments. An experimental study in which subjects were exposed to a repeated measures design. Twenty-five adult listeners with mild sloping to moderately severe sensorineural hearing loss (mean age 67 yr). Participants completed two six-week trial periods for each device type. Probe microphone, objective, and subjective measures (quiet, noise) were conducted unaided and aided at the end of each trial period. Occlusion effect results were not significantly different between the RITA and RITE instruments; however, frequency range was extended in the RITE instruments, resulting in significantly greater maximum gain for the RITE instruments than the RITA instruments at 4000 and 6000 Hz. Objective performance in quiet or in noise was unaffected by receiver location. Subjective measures revealed significantly greater satisfaction ratings for the RITE than for the RITA instruments. Similarly, preference in quiet and overall preference were significantly greater for the RITE than for the RITA instruments. Although no occlusion differences were noted between instruments, the RITE did demonstrate a significant difference in reserve gain before feedback at 4000 and 6000 Hz. Objectively; no positive benefit was noted between unaided and aided conditions on speech recognition tests. These results suggest that such testing may not be sensitive enough to determine aided benefit with open canal instruments. However, the subjective measures (Abbreviated Profile of Hearing Aid Benefit [APHAB] and subjective ratings) did indicate aided benefit for both instruments when compared to unaided. This further suggests the clinical importance of subjective measures as a way to measure aided benefit of open-fit devices.
... However, the threshold values for different vent sizes given by Kiessling et al. (2003) and Kuk and Keenan (2006) should be reconsidered when using state-of-theart feedback cancellation systems (Holube, Puder, & Velde, 2014), but revised data are not yet available. Additionally, Kießling (2006) RIC and RITA Hearing Aids Hoen and Fabry (2007) compared RIC hearing aids to traditional BTEs having custom-made earmolds and full-shell ITEs for listeners with moderate-to-severe hearing losses. In contrast to ITEs, which are worn in the ear and have a microphone and receiver close to each other, RIC hearing aids enlarge this distance by including the microphone in the BTE housing and the receiver in the ear canal. ...
... In contrast to ITEs, which are worn in the ear and have a microphone and receiver close to each other, RIC hearing aids enlarge this distance by including the microphone in the BTE housing and the receiver in the ear canal. This larger distance reduces the transmission of sound from the receiver to the microphone and, as shown in a simulation by Hoen and Fabry (2007) allow larger vents or higher gain before feedback occurs, as compared with a full-shell ITE. They also pointed out that the residual volume in the ear canal is smaller for a RIC hearing aid than for a traditional BTE or ITE device because RIC hearing aids can be placed closer to the eardrum. ...
Article
Full-text available
One of the main issues in hearing-aid fittings is the abnormal perception of the user’s own voice as too loud, “boomy,” or “hollow.” This phenomenon known as the occlusion effect be reduced by large vents in the earmolds or by open-fit hearing aids. This review provides an overview of publications related to open and closed hearing-aid fittings. First, the occlusion effect and its consequences for perception while using hearing aids are described. Then, the advantages and disadvantages of open compared with closed fittings and their impact on the fitting process are addressed. The advantages include less occlusion, improved own-voice perception and sound quality, and increased localization performance. The disadvantages associated with open-fit hearing aids include reduced benefits of directional microphones and noise reduction, as well as less compression and less available gain before feedback. The final part of this review addresses the need for new approaches to combine the advantages of open and closed hearing-aid fittings.
... Неудовлетворенность внешним видом аппарата RIC при этом не отражается на времени эксплуатации и, как мы предполагаем, нивелируется в процессе адаптации.Таким образом, RIC являются разумной альтернативой для пациентов, которые, опираясь на свои цели и ожидания, желают получить CIC, но изготовление такого аппарата по разным причинам невозможно. К тому же аппараты RIC разрешают дилемму при выборе между мощностью BTE и косметичностью CIC для пациентов с высокими степенями снижения слуха[4].Выводы1. Обоснованность применения комплексного подхода к выбору типа слухового аппарата с учетом аудиологических данных и опросника «Критерии выбора слухового аппарата» заключается в увеличении времени использования и субъективного принятия аппарата. ...
Article
Full-text available
Selection the type of hearing aid is one of the key elements of the hearing rehabilitation process, which directly affects on its effectiveness. The authors propose a method of selecting the type of hearing aid based on patient's needs — CSHA questionnaire ("Criteria for the selection of hearing aid"). The study compares the effectiveness of the hearing aid fitting when the type of hearing aid selected based on the data of the CSHA with cases where the fitting was made with another type of hearing aid. When behind-the-ear hearing aids used instead of the completely-in-the-canal (due to contraindications), preferred for the patient, it leads to a decrease time of use, overall satisfaction with the device and its appearance, increase in the number of repeated fittings. Selection of receiver-in-the-canal hearing aid instead of the completely-in-the-canal does not reduce time of use. Thus, receiver-in-the-canal hearing aids are an alternative in cases where there are contraindications to the use of completely-in-the-canal hearing aids without compromising the effectiveness. The use of the CSHA method in audiology practice will improve the efficiency of electroacoustic correction and reduce the number of failures from the use of hearing aids. Keywords: results of hearing rehabilitation; types of hearing aids.
Article
To select hearing aid is an essential process for successful hearing rehabilitation. The purpose of this study is to review hearing aid selection considerations between receiver in-the-canal (RIC) and custom hearing aid (CHA) in order to guide appropriate selection of the hearing aid. This study discussed three key factors in the hearing aid selection including physical, acoustic and electroacoustic characteristics and other aspects. Advantages of RIC types are comfort to wear, reduction of the occlusion effect, presence of directional microphones, on-site fit, easy connectivity with other devices, and use of rechargeable batteries. On the other hand, the CHA types have their advantage in terms of being comfort to wear with masks, proper insertion and placement, reduction of the acoustic feedback, good approximation of frequency response curve, improvement of speech in noise perception, expanded hearing aid candidacy with varying hearing thresholds, and easy telephone use. We concluded that appropriate selection of the hearing aid would contribute to successful hearing rehabilitation, if considering physical, psycho-social, and acoustical characteristics.
Article
Full-text available
Purpose: To calculate the real-ear insertion gain (REIG) according to the types of hearing aids, we evaluated the preferred REIGs of Korean hearing-impaired listeners and psychoacoustic differences between open-canal fitting (OF) and closed-canal fitting (CF).Methods: The subjects with sensorineural hearing loss were divided into OF group (4 monaural fittings, 15 binaural fittings with 34 ears), and CF group (8 monaural fittings, 13 binaural fittings with 34 ears). There were no statistical differences in hearing threshold level (HTL) at each octave frequencies, word recognition score (WRS) and Korean Adaptation of the International Outcome Inventory for Hearing Aids (K-IOI-HA) between the two groups. When there was no need for further electroacoustic adjustment of the hearing aid, sharpness and occlusion of amplified sound, clarity of sentence, and loudness of noise were evaluated based on the everyday experience. And REIGs with international speech test signal and WRS in sound-treated room were measured.Results: Preferred REIG for HTL was low for OF compared to CF in 0.5 kHz and 0.75 kHz at input SPL of 55 dB, 0.5 kHz at 60 dB SPL, 0.25 kHz and 0.5 kHz at 80 dB SPL. However, there were no differences in aided WRS and psychoacoustics between the two groups.Conclusion: In this study, the preferred REIG of OF and CF groups showed a difference under 0.75 kHz although there were no psychoacoustic differences between the two groups. Therefore, the results of this study should be considered when formulating Korean-type hearing aid fitting formula.
Article
The aim of this study was to compare the degree of satisfaction of the patients, hearing loss type and severity, and satisfactory and unsatisfactory factors between closed fit hearing aid (HA) and receiver in the canal (RIC) HA.
Article
Background: In spite of early identification and intervention efforts achieved by Early Hearing Detection and Intervention (EHDI) programs, many infants with hearing loss experience delays in early vocabulary development in comparison to peers with normal hearing (Mayne, Yoshinaga-Itano, Sedey, 2000a; Mayne, Yoshinaga-Itano, Sedey, Carey, 2000b; Moeller et al, 2007a, 2007b). One of the several factors that may contribute to individual differences in outcomes is inconsistent hearing aid use in this age group. This may be associated with the physical fit when using traditional behind-the-ear (BTE) hearing aids, since they are relatively large in comparison with the small and soft ear of an infant. Receiver-in-the-ear (RITE) hearing aids may be advantageous for use in pediatric fittings, since they are very tiny and lightweight and therefore sit comfortably on a small soft ear. Purpose: To evaluate the use of a RITE hearing aid with an instant ear-tip especially developed for infants in terms of physical fit, stability, safety, and security of the device, as well as the use of retention tools (remedies for keeping the hearing aid securely on the ear) with this age group. Research design: A longitudinal study with hearing impaired infants fitted with RITE hearing aids was performed. Study sample: Eighteen infants with mild to moderate/severe hearing loss participated in the study. The age range was 2-36 mo. Sixteen infants had worn hearing aids prior to their participation in the study. Intervention: Each hearing impaired infant was fitted with the RITE hearing aid and an instant ear-tip, the size of which was chosen by the audiologist. The infants used the device for a period of 2-5 mo. Data collection and analysis: Audiologists and parents completed questionnaires at every visit (5-7 visits in total). Responses were obtained using a category rating scale (Stevens, 1975) from 0 to 10. The data were analyzed using descriptive statistics and nonparametric statistics. Results: Sixteen of the 18 children completed the study. At the end of the study, 11 of the 16 children were using the instant ear-tip, whereas five children were fitted with the receiver mounted in a custom earmold. The audiologists rated the RITE solution to provide a safe, stable, and secure fit. The general trend was that ratings improved over time. At the final follow-up session, all median ratings were between 8 and 10. Conclusions: Based on the positive results obtained in the study, the use of an appropriately designed RITE hearing aid is recommended for infants.
Article
Full-text available
In a series of experiments, we introduced peaks of 10, 20, and 30 dB, in various combinations, onto a smooth reference frequency response. For each of the conditions, we evaluated speech intelligibility in noise, using a test as developed by Plomp and Mimpen (1979), and sound quality (for both speech and music), using a rating-scale procedure. We performed the experiments with 26 listeners with sensorineurally impaired hearing and 10 listeners with normal hearing. Signal processing was accomplished digitally; for each listener, the stimuli were filtered and subsequently amplified so that the average speech spectrum was well above the threshold of hearing at all frequencies. The results show that, as a result of the introduction of peaks onto the frequency response, speech intelligibility is affected more for the listeners with impaired hearing than for those with normal hearing. Sound-quality judgments tend to be less different between the listener groups. Conditions with 30-dB peaks especially show serious effects on both speech intelligibility and sound quality.
Article
Full-text available
Comparisons were made between changes in the audibility of bone-conduction stimuli to differences in the sound pressure present in the external auditory canal when ears were occluded. Fifteen listeners with normal middle ear function were tested using pure tones of 250, 500, and 1000 Hz, delivered via a bone-conduction oscillator placed on the mastoid process and the frontal bone. At all three frequencies, and both sites of stimulation, ear canal sound pressures were greater in the occluded than in the unoccluded conditions. Concurrently, the test signals were detected at lower intensities, although the changes in audibility and external canal sound pressure levels were not unity. The occlusion effect was attenuated slightly when the skull was vibrated from the frontal bone.
Article
Full-text available
Variations in the loop response of hearing aids caused by jaw movements, variations in acoustics outside the ear, and variations of vent size have been identified. Behind The Ear (BTE) and In The Ear Canal (ITEC) hearing aids were considered. The largest variations among the variations of the acoustics outside the ear, except when the hearing aid was partly removed, were found with the ITEC when a telephone set was placed by the ear. The variations of the loop response caused by changes in vent size were compared with the variations of a theoretical model of the feedback path. The theoretical model was also used to compare the feedback of different designs of the vent that gives the same acoustic impedance at low frequencies. The calculated feedback was less with the short vents (12 mm) than the long vents (24 mm).
Article
Full-text available
Twenty individuals were tested to determine the occlusion effect caused by supraaural earphones and by insert earphones with shallow and deep insertion of its foam eartip. The bone-conduction oscillator was placed both on the forehead and the mastoid. It was concluded that using deeply inserted earphones is the most practical way in which to carry out clinical bone-conduction measurements.
Article
Full-text available
In this study the potential benefit of hearing instruments with multi-microphone technology was investigated in laboratory and in field tests for users with severe-to-profound hearing loss. Twenty-one experienced hearing aid users were fitted with high-power multi-microphone hearing instruments (Phonak PowerZoom P4 AZ). The following evaluations were performed: (i) adaptive speech test (SRT for HSM sentence test) in quiet and in noise with their own instrument and the test instrument in the omnidirectional (basic program) and directional mode (party noise profound+zoom algorithm). (ii) Paired comparisons of loudness, sound quality and speech intelligibility for both the omni and zoom program. (iii) Questionnaires on satisfaction and self-assessment of communication in different listening conditions (Oldenburg Inventory). Only 10 subjects achieved 50% correct (SRT) on the sentence test in noise (speech 0 degrees/noise 180 degrees) with both their own instrument and the test instrument in the omnidirectional mode. However, 15 subjects succeeded in the SRT measurement in the directional mode. The average SRT improvement of the directional over the omnidirectional mode was 13.7 dB. Loudness was judged 'medium loud' for both listening programs. Sound quality and intelligibility were rated significantly better for the zoom program. Compared to their own instrument users' satisfaction with the test instrument was significantly higher, especially in noisy listening situations.
Article
Full-text available
We determined how the perceived naturalness of music and speech (male and female talkers) signals was affected by various forms of linear filtering, some of which were intended to mimic the spectral "distortions" introduced by transducers such as microphones, loudspeakers, and earphones. The filters introduced spectral tilts and ripples of various types, variations in upper and lower cutoff frequency, and combinations of these. All of the differently filtered signals (168 conditions) were intermixed in random order within one block of trials. Levels were adjusted to give approximately equal loudness in all conditions. Listeners were required to judge the perceptual quality (naturalness) of the filtered signals on a scale from 1 to 10. For spectral ripples, perceived quality decreased with increasing ripple density up to 0.2 ripple/ERB(N) and with increasing ripple depth. Spectral tilts also degraded quality, and the effects were similar for positive and negative tilts. Ripples and/or tilts degraded quality more when they extended over a wide frequency range (87-6981 Hz) than when they extended over subranges. Low- and mid-frequency ranges were roughly equally important for music, but the mid-range was most important for speech. For music, the highest quality was obtained for the broadband signal (55-16,854 Hz). Increasing the lower cutoff frequency from 55 Hz resulted in a clear degradation of quality. There was also a distinct degradation as the upper cutoff frequency was decreased from 16,845 Hz. For speech, there was a marked degradation when the lower cutoff frequency was increased from 123 to 208 Hz and when the upper cutoff frequency was decreased from 10,869 Hz. Typical telephone bandwidth (313 to 3547 Hz) gave very poor quality.
Article
Full-text available
The current study reexamined the effect of vent diameters on objective and subjective occlusion effect (OE) while minimizing two possible sources of variability. Nine hearing-impaired participants with primarily a high-frequency hearing loss were evaluated. Laser shell-making technology was used to make ear inserts of completely-in-the-canal (CIC) hearing aids for the study. This was to minimize any potential slit leakage from the inserts. The vent dimensions were systematically altered during the study. Participants sustained /i/ for 5 sec, and the real-ear occluded response was measured with a custom-made program that performed frequency averaging to reduce response variability. Participants also repeated the phrase "Baby Jeannie is teeny tiny" and rated their own voice. The results showed a systematic change in the objective OE and subjective ratings of OE as the vent diameter was modified. Furthermore, a significant correlation was seen between subjective rating and objective occlusion effect.
Article
The purpose of this investigation was to examine the potential for directional hearing aid benefit in listeners with severe hearing loss at multiple SNRs for both auditory only and audio-visual presentation modes. Speech recognition performance was measured using the connected speech test at six SNRs individually determined for each subject in order to avoid floor an ceiling effects. The results revealed significant directional benefit was present at all tested SNRs in the presence of visual information. For auditory only presentations, significant directional benefit was only present at the least positive SNR. The largest directional benefit was measured at the poorest tested SNR for both auditory only and audiovisual presentation modes. The results of this study generally support small but significant directional for listeners with severe hearing loss benefit in a difficult listening environment both with and without the presence of visual information.
Article
Mit Hilfe eines Hörtrupps wurden einige Hörversuche gemacht um festzustellen, welche Unregelmäßigkeiten in der Frequenzkurve bei elektroakustischer Ubertragung subjektiv noch wahrnehmbar sind. Die Hörversuche wurden durchgeführt mit Musik, Sprache und weißem Rauschen als Testschall. Es zeigt sich, daß Höcker in der Frequenzkurve weit störender sind als entsprechende Senken. Auch werden Anhebungen dann noch gehört, wenn gleich große Absenkungen nicht mehr wahrnehmbar sind. Bei einigen Verständlichkeitsmessungen mit Höckern oder Senken im Sprachübertragungsbereich ergibt sich, daß die Höcker eine größere Verständlichkeitsminderung bewirken als die entsprechenden Senken.
Article
The psychophysical relations between loudspeakers' frequency response and their perceptual properties were investigated. The frequency response of 18 high-fidelity loudspeakers was measured in three different conditions: in free field, in reverberation room, and in the listening room itself. The perceptual data consisted of experienced listeners' ratings of the same loudspeakers in seven scales: clarity, fullness, spaciousness, brightness, softness, absence of extraneous sounds, and fidelity (Gabrielsson and Lindstrom, 1985). Hypotheses concerning the psychophysical relations were stated on the basis of results from earlier listening tests. The relations obtained with measurements in the listening room showed better agreement with the hypotheses than those obtained by measurements in free field or in reverberation room.
Article
In a survey of more than 1500 current users of hearing instruments, half of which were digital, overall customer satisfaction was measured at 71% for hearing instruments 0-5 years old. Customer satisfaction with 1-year-old instruments was 78%, which placed hearing instruments in the top third of all products and services in the United States as measured by the University of Michigan. Hearing care professionals received stellar ratings approaching perfection. Overall they achieved a 92% satisfaction rating. Eighty-five percent of consumers are satisfied with the ability of their instruments to improve their hearing, meaning they are deriving tremendous benefit. In 15 listening situations, customer satisfaction ranges from 90% (one-on-one) to 59% (cell phone). Six out often consumers are satisfied with their instruments in 80% of the listening situations measured in this study. Hearing instruments are beneficial all along the hearing loss continuum. However, ratings are significantly lower for the severe-to-profound hearing loss population (i.e., the 20% of people with the most severe hearing loss). Significant opportunity remains to meet the needs of people with the greatest hearing losses. For example, fewer than 1% of consumers own an FM assistive listening system and only 25% use directional microphones or telecoils. The use of digital hearing instruments is associated with significantly higher ratings on overall satisfaction and benefit, improved sound quality, reduction in feedback, improved performance in noisy situations, and greater utility in a number of important listening situations.
Article
Sound pressure measurements were made at the hearing aid microphones of 20 subjects with their in-the-ear (ITE) hearing aids and a behind-the-ear (BTE) hearing aid to determine the influence of microphone location on hearing aid input. A probe tube microphone was used to measure the difference in dB SPL between the ITE and BTE microphone locations. ITE microphone location resulted in a maximum high frequency advantage of 9.2 dB in the 2500 to 5000 Hz range. However, the frequency location of this maximal advantage varied a great deal between individuals, precluding the use of a standard ITE microphone correction factor for 2cc coupler to functional gain conversions.
Article
Three programs (female voice, jazz music, and pink noise) were reproduced using four different frequency responses and two different sound levels. Fourteen normal hearing subjects listened to the reproduction via earphones and judged the sound quality on seven perceptual scales (loudness, clarity, fullness, spaciousness, brightness, softness/gentleness, and nearness) and a fidelity scale. Significant differences among the reproductions appeared in all scales and could be attributed to the differences in frequency response or sound level or both. Interactions between the reproductions and the programs could be explained by the relations between the spectrum of the programs and the frequency responses used. The results for the noise program were similar to those for the jazz music program.
Article
Although earmould venting is considered to make an earmould more comfortable, whether it does so remains to be proven in hearing-aid users. A hundred and six patients were sequentially fitted with a hearing aid in a randomized order with an unvented, a 0.8 mm vented or a 2 mm vented mould and questioned about various aspects of discomfort at the end of each trial period. The three moulds were equally uncomfortable (approximately 17% overall), moist (approximately 34% overall) and associated with an itchy sensation (approximately 36% overall). However, a 0.8 mm and a 2 mm vent significantly reduced the sensation of blockage from 35 to 22% (P less than 0.05) and 13% (P less than 0.001) respectively. A potential disadvantage of venting is feedback, but patients' reports of this can be confused with feedback due to incorrectly inserting the mould. A separate study showed that a 2 mm vent might cause feedback in approximately 10% of patients when used in conjunction with behind-the-ear aids whose maximum gain was 45 dB, but only when the gain was at 42 dB or greater.
Article
When an earmould is vented, either to relieve sensations of blockage or to modify the frequency response of a hearing aid system, the gain setting at which feedback occurs is lowered. Although this principle is widely appreciated, the typical gains at which feedback occurs have received little systematic study and vented earmoulds are still prescribed on largely rule-of-thumb, or trial and error basis. In a laboratory study on a KEMAR mannikin the effects for hearing aids with gains up to 64 dB were studied. The acoustical stimuli were varied (using speech-shaped noise, wide-band noise and narrow bands of noise), as were the size of the parallel vent (0.8 and 2.0 mm) and the orientation of the microphone on the aid (forward-facing and downward-facing). The results suggest that: a forward-facing microphone is less susceptible to oscillatory feedback than a downward-facing one; while a 2 mm vent leads to more feedback limitations than a 0.8 mm vent, the smaller vent is more than a 'pressure vent', having some acoustical effects; and the spectrum of the ambient acoustics can markedly reduce the available gain before the onset of oscillation, e.g. from greater than 40 dB to less than 20 dB gain.
Article
In a series of experiments, we introduced peaks of 10, 20, and 30 dB, in various combinations, onto a smooth reference frequency response. For each of the conditions, we evaluated speech intelligibility in noise, using a test as developed by Plomp and Mimpen (1979), and sound quality (for both speech and music), using a rating-scale procedure. We performed the experiments with 26 listeners with sensorineurally impaired hearing and 10 listeners with normal hearing. Signal processing was accomplished digitally; for each listener, the stimuli were filtered and subsequently amplified so that the average speech spectrum was well above the threshold of hearing at all frequencies. The results show that, as a result of the introduction of peaks onto the frequency response, speech intelligibility is affected more for the listeners with impaired hearing than for those with normal hearing. Sound-quality judgments tend to be less different between the listener groups. Conditions with 30-dB peaks especially show serious effects on both speech intelligibility and sound quality.
Article
In this study the occlusion effect was quantified for five types of earmolds with different venting. Nine normal-hearing listeners and ten experienced hearing aid users were provided with conventional earmolds with 1.6 and 2.4 mm circular venting, shell type earmolds with a novel vent design with equivalent cross-sectional vent areas, and nonoccluding soft silicone eartips of a commercial hearing instrument. For all venting systems, the occlusion effect was measured using a probe microphone system and subjectively rated in test and retest sessions. The results for both normal-hearing subjects and hearing aid users showed that the novel vents caused significantly less occlusion than the traditional vents. Occlusion effect associated with the soft silicone eartip was comparable to the nonoccluded ear. Test-retest reproducibility was higher for the subjective occlusion rating than for the objectively measured occlusion. Perceived occlusion revealed a closer relationship to measured occlusion in the ear in which the measured occlusion effect was higher ("high OE" ear) than in the "low OE" ear. As our results suggest that subjective judgment of occlusion is directly related to the acoustic mass of the air column in the vent, the amount of perceived occlusion may be predicted by the vent dimensions.
Article
The purpose of this investigation was to examine the potential for directional hearing aid benefit in listeners with severe hearing loss at multiple SNRs for both auditory only and audio-visual presentation modes. Speech recognition performance was measured using the connected speech test at six SNRs individually determined for each subject in order to avoid floor and ceiling effects. The results revealed significant directional benefit was present at all tested SNRs in the presence of visual information. For auditory only presentations, significant directional benefit was only present at the least positive SNR. The largest directional benefit was measured at the poorest tested SNR for both auditory only and audiovisual presentation modes. The results of this study generally support small but significant directional for listeners with severe hearing loss benefit in a difficult listening environment both with and without the presence of visual information.
The HR 2006 dispenser survey.
  • Strom
Strom KE: The HR 2006 dispenser survey. Hear Rev 2006;11(6):16-39.
Der markt fur horsysteme in Europa.
  • Salmon
Salmon TG: Der markt für hörsysteme in Europa. AudioInfos 2006;64:1-4.
  • K Wagener
  • T Brand
  • B Kollmeier
Wagener K, Brand T, Kollmeier B: Z für Audiologie. 1999;38(3):86-95.