Microphone Directionality, Pre-Emphasis Filter, and Wind Noise in Cochlear Implants

Background: Wind noise can be a nuisance or a debilitating masker for cochlear implant users in outdoor environments. Previous studies indicated that wind noise at the microphone/hearing aid output had high levels of low-frequency energy and the amount of noise generated is related to the microphone directionality. Currently, cochlear implants only offer either directional microphones or omnidirectional microphones for users at-large. As all cochlear implants utilize pre-emphasis filters to reduce low-frequency energy before the signal is encoded, effective wind noise reduction algorithms for hearing aids might not be applicable for cochlear implants. Purpose: The purposes of this study were to investigate the effect of microphone directionality on speech recognition and perceived sound quality of cochlear implant users in wind noise and to derive effective wind noise reduction strategies for cochlear implants. Research Design: A repeated-measure design was used to examine the effects of spectral and temporal masking created by wind noise recorded through directional and omnidirectional microphones and the effects of pre-emphasis filters on cochlear implant performance. A digital hearing aid was programmed to have linear amplification and relatively flat in-situ frequency responses for the directional and omnidirectional modes. The hearing aid output was then recorded from 0 to 360° at flow velocities of 4.5 and 13.5 m/sec in a quiet wind tunnel. Study Sample: Sixteen postlingually deafened adult cochlear implant listeners who reported to be able to communicate on the phone with friends and family without text messages participated in the study. Intervention: Cochlear implant users listened to speech in wind noise recorded at locations that the directional and omnidirectional microphones yielded the lowest noise levels. Data Collection and Analysis: Cochlear implant listeners repeated the sentences and rated the sound quality of the testing materials. Spectral and temporal characteristics of flow noise, as well as speech and/or noise characteristics before and after the pre-emphasis filter, were analyzed. Correlation coefficients between speech recognition scores and crest factors of wind noise before and after pre-emphasis filtering were also calculated. Results: Listeners obtained higher scores using the omnidirectional than the directional microphone mode at 13.5 m/sec, but they obtained similar speech recognition scores for the two microphone modes at 4.5 m/sec. Higher correlation coefficients were obtained between speech recognition scores and crest factors of wind noise after pre-emphasis filtering rather than before filtering. Conclusion: Cochlear implant users would benefit from both directional and omnidirectional microphones to reduce far-field background noise and near-field wind noise. Automatic microphone switching algorithms can be more effective if the incoming signal were analyzed after pre-emphasis filters for microphone switching decisions.

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Clinical Application of Spectral Modulation Detection: Speech Recognition Benefit for Combining a Cochlear Implant and Contralateral Hearing Aid

Journal of Speech Language and Hearing Research ◽

10.1044/2020_jslhr-19-00304 ◽

2020 ◽

Vol 63 (5) ◽

pp. 1561-1571 ◽

Cited By ~ 1

Author(s):

David M. Kessler ◽

Jace Wolfe ◽

Michelle Blanchard ◽

René H. Gifford

Keyword(s):

Speech Recognition ◽

Cochlear Implant ◽

Hearing Aid ◽

Clinical Sample ◽

Low Frequency ◽

Spectral Modulation ◽

Pure Tone Average ◽

Recognition Testing ◽

Modulation Detection ◽

The Relationship

Purpose The purpose of this study was to investigate the relationship between speech recognition benefit derived from the addition of a hearing aid (HA) to the nonimplanted ear (i.e., bimodal benefit) and spectral modulation detection (SMD) performance in the nonimplanted ear in a large clinical sample. An additional purpose was to investigate the influence of low-frequency pure-tone average (PTA) of the nonimplanted ear and age at implantation on the variance in bimodal benefit. Method Participants included 311 unilateral cochlear implant (CI) users who wore an HA in the nonimplanted ear. Participants completed speech recognition testing in quiet and in noise with the CI-alone and in the bimodal condition (i.e., CI and contralateral HA) and SMD in the nonimplanted ear. Results SMD performance in the nonimplanted ear was significantly correlated with bimodal benefit in quiet and in noise. However, this relationship was much weaker than previous reports with smaller samples. SMD, low-frequency PTA of the nonimplanted ear from 125 to 750 Hz, and age at implantation together accounted for, at most, 19.1% of the variance in bimodal benefit. Conclusions Taken together, SMD, low-frequency PTA, and age at implantation account for the greatest amount of variance in bimodal benefit than each variable alone. A large portion of variance (~80%) in bimodal benefit is not explained by these variables. Supplemental Material https://doi.org/10.23641/asha.12185493

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The Effect of Hearing Aid Bandwidth and Configuration of Hearing Loss on Bimodal Speech Recognition in Cochlear Implant Users

Ear and Hearing ◽

10.1097/aud.0000000000000638 ◽

2019 ◽

Vol 40 (3) ◽

pp. 621-635 ◽

Cited By ~ 8

Author(s):

Arlene C. Neuman ◽

Annette Zeman ◽

Jonathan Neukam ◽

Binhuan Wang ◽

Mario A. Svirsky

Keyword(s):

Hearing Loss ◽

Speech Recognition ◽

Cochlear Implant ◽

Hearing Aid

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Auditory Speech Perception Development in Relation to Patient's Age with Cochlear Implant

International Archives of Otorhinolaryngology ◽

10.1055/s-0036-1584296 ◽

2016 ◽

Vol 21 (03) ◽

pp. 206-212 ◽

Cited By ~ 3

Author(s):

Grace Ciscare ◽

Erika Mantello ◽

Carla Fortunato-Queiroz ◽

Miguel Hyppolito ◽

Ana Reis

Keyword(s):

Speech Perception ◽

Cochlear Implant ◽

Cochlear Implants ◽

Statistical Difference ◽

Hearing Aid ◽

Age Groups ◽

Auditory Thresholds ◽

Caregiver Education ◽

Auditory Speech ◽

Hearing Aid Use

Introduction A cochlear implant in adolescent patients with pre-lingual deafness is still a debatable issue. Objective The objective of this study is to analyze and compare the development of auditory speech perception in children with pre-lingual auditory impairment submitted to cochlear implant, in different age groups in the first year after implantation. Method This is a retrospective study, documentary research, in which we analyzed 78 reports of children with severe bilateral sensorineural hearing loss, unilateral cochlear implant users of both sexes. They were divided into three groups: G1, 22 infants aged less than 42 months; G2, 28 infants aged between 43 to 83 months; and G3, 28 older than 84 months. We collected medical record data to characterize the patients, auditory thresholds with cochlear implants, assessment of speech perception, and auditory skills. Results There was no statistical difference in the association of the results among groups G1, G2, and G3 with sex, caregiver education level, city of residence, and speech perception level. There was a moderate correlation between age and hearing aid use time, age and cochlear implants use time. There was a strong correlation between age and the age cochlear implants was performed, hearing aid use time and age CI was performed. Conclusion There was no statistical difference in the speech perception in relation to the patient's age when cochlear implant was performed. There were statistically significant differences for the variables of auditory deprivation time between G3 - G1 and G2 - G1 and hearing aid use time between G3 - G2 and G3 - G1.

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Amount of Frequency Compression in Bimodal Cochlear Implant Users Is a Poor Predictor for Audibility and Spatial Hearing

Journal of Speech Language and Hearing Research ◽

10.1044/2021_jslhr-20-00653 ◽

2021 ◽

pp. 1-14

Author(s):

Snandan Sharma ◽

Waldo Nogueira ◽

A. John van Opstal ◽

Josef Chalupper ◽

Lucas H. M. Mens ◽

...

Keyword(s):

Speech Recognition ◽

Cochlear Implant ◽

Sound Localization ◽

High Frequency ◽

Hearing Aid ◽

Spatial Hearing ◽

Meaningful Improvement ◽

Frequency Compression ◽

Knee Point ◽

Localization Performance

Purpose Speech understanding in noise and horizontal sound localization is poor in most cochlear implant (CI) users with a hearing aid (bimodal stimulation). This study investigated the effect of static and less-extreme adaptive frequency compression in hearing aids on spatial hearing. By means of frequency compression, we aimed to restore high-frequency audibility, and thus improve sound localization and spatial speech recognition. Method Sound-detection thresholds, sound localization, and spatial speech recognition were measured in eight bimodal CI users, with and without frequency compression. We tested two compression algorithms: a static algorithm, which compressed frequencies beyond the compression knee point (160 or 480 Hz), and an adaptive algorithm, which aimed to compress only consonants leaving vowels unaffected (adaptive knee-point frequencies from 736 to 2946 Hz). Results Compression yielded a strong audibility benefit (high-frequency thresholds improved by 40 and 24 dB for static and adaptive compression, respectively), no meaningful improvement in localization performance (errors remained > 30 deg), and spatial speech recognition across all participants. Localization biases without compression (toward the hearing-aid and implant side for low- and high-frequency sounds, respectively) disappeared or reversed with compression. The audibility benefits provided to each bimodal user partially explained any individual improvements in localization performance; shifts in bias; and, for six out of eight participants, benefits in spatial speech recognition. Conclusions We speculate that limiting factors such as a persistent hearing asymmetry and mismatch in spectral overlap prevent compression in bimodal users from improving sound localization. Therefore, the benefit in spatial release from masking by compression is likely due to a shift of attention to the ear with the better signal-to-noise ratio facilitated by compression, rather than an improved spatial selectivity. Supplemental Material https://doi.org/10.23641/asha.16869485

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Speech Perception Benefit for Children with a Cochlear Implant and a Hearing Aid in Opposite Ears and Children with Bilateral Cochlear Implants

Audiology and Neurotology ◽

10.1159/000219487 ◽

2010 ◽

Vol 15 (1) ◽

pp. 44-56 ◽

Cited By ~ 65

Author(s):

Mansze Mok ◽

Karyn L. Galvin ◽

Richard C. Dowell ◽

Colette M. McKay

Keyword(s):

Speech Perception ◽

Cochlear Implant ◽

Cochlear Implants ◽

Hearing Aid ◽

Bilateral Cochlear Implants

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A Longitudinal Study in Adults With Sequential Bilateral Cochlear Implants: Time Course for Individual Ear and Bilateral Performance

Journal of Speech Language and Hearing Research ◽

10.1044/2014_jslhr-h-13-0087 ◽

2014 ◽

Vol 57 (3) ◽

pp. 1108-1126 ◽

Cited By ~ 19

Author(s):

Ruth M. Reeder ◽

Jill B. Firszt ◽

Laura K. Holden ◽

Michael J. Strube

Keyword(s):

Longitudinal Study ◽

Speech Recognition ◽

Cochlear Implant ◽

Cochlear Implants ◽

Time Course ◽

Performance Outcomes ◽

Prospective Longitudinal Study ◽

Early Improvement ◽

Prospective Longitudinal ◽

The Impact

PurposeThe purpose of this study was to examine the rate of progress in the 2nd implanted ear as it relates to the 1st implanted ear and to bilateral performance in adult sequential cochlear implant recipients. In addition, this study aimed to identify factors that contribute to patient outcomes.MethodThe authors performed a prospective longitudinal study in 21 adults who received bilateral sequential cochlear implants. Testing occurred at 6 intervals: prebilateral through 12 months postbilateral implantation. Measures evaluated speech recognition in quiet and noise, localization, and perceived benefit.ResultsSecond ear performance was similar to 1st ear performance by 6 months postbilateral implantation. Bilateral performance was generally superior to either ear alone; however, participants with shorter 2nd ear length of deafness (<20 years) had more rapid early improvement and better overall outcomes than those with longer 2nd ear length of deafness (>30 years). All participants reported bilateral benefit.ConclusionsAdult cochlear implant recipients demonstrated benefit from 2nd ear implantation for speech recognition, localization, and perceived communication function. Because performance outcomes were related to length of deafness, shorter time between surgeries may be warranted to reduce negative length-of-deafness effects. Future study may clarify the impact of other variables, such as preimplant hearing aid use, particularly for individuals with longer periods of deafness.

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Recognition and Localization of Speech by Adult Cochlear Implant Recipients Wearing a Digital Hearing Aid in the Nonimplanted Ear (Bimodal Hearing)

Journal of the American Academy of Audiology ◽

10.3766/jaaa.20.6.4 ◽

2009 ◽

Vol 20 (06) ◽

pp. 353-373 ◽

Cited By ~ 77

Author(s):

Lisa G. Potts ◽

Margaret W. Skinner ◽

Ruth A. Litovsky ◽

Michael J. Strube ◽

Francis Kuk

Keyword(s):

Speech Recognition ◽

Cochlear Implant ◽

Repeated Measures ◽

Dynamic Range ◽

Hearing Aid ◽

Bilateral Stimulation ◽

Bimodal Condition ◽

Digital Hearing Aid ◽

Loudness Growth ◽

Bimodal Hearing

Background: The use of bilateral amplification is now common clinical practice for hearing aid users but not for cochlear implant recipients. In the past, most cochlear implant recipients were implanted in one ear and wore only a monaural cochlear implant processor. There has been recent interest in benefits arising from bilateral stimulation that may be present for cochlear implant recipients. One option for bilateral stimulation is the use of a cochlear implant in one ear and a hearing aid in the opposite nonimplanted ear (bimodal hearing). Purpose: This study evaluated the effect of wearing a cochlear implant in one ear and a digital hearing aid in the opposite ear on speech recognition and localization. Research Design: A repeated-measures correlational study was completed. Study Sample: Nineteen adult Cochlear Nucleus 24 implant recipients participated in the study. Intervention: The participants were fit with a Widex Senso Vita 38 hearing aid to achieve maximum audibility and comfort within their dynamic range. Data Collection and Analysis: Soundfield thresholds, loudness growth, speech recognition, localization, and subjective questionnaires were obtained six–eight weeks after the hearing aid fitting. Testing was completed in three conditions: hearing aid only, cochlear implant only, and cochlear implant and hearing aid (bimodal). All tests were repeated four weeks after the first test session. Repeated-measures analysis of variance was used to analyze the data. Significant effects were further examined using pairwise comparison of means or in the case of continuous moderators, regression analyses. The speech-recognition and localization tasks were unique, in that a speech stimulus presented from a variety of roaming azimuths (140 degree loudspeaker array) was used. Results: Performance in the bimodal condition was significantly better for speech recognition and localization compared to the cochlear implant–only and hearing aid–only conditions. Performance was also different between these conditions when the location (i.e., side of the loudspeaker array that presented the word) was analyzed. In the bimodal condition, the speech-recognition and localization tasks were equal regardless of which side of the loudspeaker array presented the word, while performance was significantly poorer for the monaural conditions (hearing aid only and cochlear implant only) when the words were presented on the side with no stimulation. Binaural loudness summation of 1–3 dB was seen in soundfield thresholds and loudness growth in the bimodal condition. Measures of the audibility of sound with the hearing aid, including unaided thresholds, soundfield thresholds, and the Speech Intelligibility Index, were significant moderators of speech recognition and localization. Based on the questionnaire responses, participants showed a strong preference for bimodal stimulation. Conclusions: These findings suggest that a well-fit digital hearing aid worn in conjunction with a cochlear implant is beneficial to speech recognition and localization. The dynamic test procedures used in this study illustrate the importance of bilateral hearing for locating, identifying, and switching attention between multiple speakers. It is recommended that unilateral cochlear implant recipients, with measurable unaided hearing thresholds, be fit with a hearing aid.

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Wind Noise Reduction for Outdoor Measurement Microphones With Windscreens

ASME 2008 Noise Control and Acoustics Division Conference ◽

10.1115/ncad2008-73084 ◽

2008 ◽

Author(s):

Z. C. Zheng ◽

Ying Xu

Keyword(s):

Noise Reduction ◽

High Frequency ◽

Low Frequency ◽

High Flow ◽

Low Flow ◽

Computational Techniques ◽

Wind Noise ◽

Flow Resistivity ◽

Materials Used ◽

Wind Noise Reduction

In this study, effects of windscreen material property on wind noise reduction are investigated at different frequencies of incoming wind turbulence. The properties of porous materials used for the windscreen are represented by flow resistivity. Computational techniques are developed to study the detailed flow around the windscreen as well as flow inside the windscreen that uses a porous material as the medium. The coupled simulation shows that for low-frequency turbulence, the windscreens with low flow resistivity are more effective in noise reduction. Contrarily, for high-frequency turbulence, the windscreens with high flow resistivity are more effective.

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Effects of Universal Newborn Hearing Screening on an Early Intervention Program for Children with Hearing Loss, Birth to 3 Yr of Age

Journal of the American Academy of Audiology ◽

10.3766/jaaa.21.3.5 ◽

2010 ◽

Vol 21 (03) ◽

pp. 169-175 ◽

Cited By ~ 24

Author(s):

Kathy S. Halpin ◽

Kay Y. Smith ◽

Judith E. Widen ◽

Mark E. Chertoff

Keyword(s):

Hearing Loss ◽

Cochlear Implants ◽

Hearing Aids ◽

Late Onset ◽

Hearing Aid ◽

Profound Hearing Loss ◽

Universal Newborn Hearing Screening ◽

Before And After ◽

Age Of Diagnosis ◽

Diagnosis Age

Background: Universal Newborn Hearing Screening (UNHS) was introduced in Kansas in 1999. Prior to UNHS a small percentage of newborns were screened for and identified with hearing loss. Purpose: The purpose of this study was to determine the effects of UNHS on a local early intervention (EI) program for young children with hearing loss. Research Design: This was a retrospective study based on the chart review of children enrolled in the EI program during target years before and after the establishment of UNHS. Study Sample: Charts for 145 children were reviewed. Data Collection and Analysis: The chart review targeted the following aspects of the EI program: caseload size, percentage of caseload identified by UNHS, age of diagnosis, age of enrollment in EI, degree of hearing loss, etiology of hearing loss, late onset of hearing loss, age of hearing aid fit, percentage of children fit with hearing aids by 6 mo, percentage of children with profound hearing loss with cochlear implants, and percentage of children with additional disabilities. Results: Changes in the EI program that occurred after UNHS were increases in caseload size, percentage of caseload identified by UNHS, percentage of children fit with hearing aids by 6 mo of age, and percentage of children with profound hearing loss with cochlear implants. There were decreases in age of diagnosis, age of enrollment in EI, and age of hearing aid fit. Before UNHS, the majority of children had severe and profound hearing loss; after UNHS there were more children with mild and moderate hearing loss. The percentage of known etiology and late-onset hearing loss was approximately the same before and after UNHS, as was the percentage of children with additional disabilities. Conclusion: UNHS had a positive impact on caseload size, age of diagnosis, age of enrollment in EI, and age of hearing aid fit. The percentage of the caseload identified in the newborn period was about 25% before UNHS and over 80% after its implementation. After UNHS, the EI caseload included as many children with mild and moderate hearing loss as with severe and profound loss. By the last reporting year in the study (academic year 2005–2006) all children with profound hearing losses had cochlear implants.

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