A Meta-analytic Comparison of Binaural Benefits between Bilateral Cochlear Implants and Bimodal Stimulation

2007 ◽  
Vol 18 (09) ◽  
pp. 760-776 ◽  
Author(s):  
Erin C. Schafer ◽  
Amyn M. Amlani ◽  
Andi Seibold ◽  
Pamela L. Shattuck
Keyword(s):  
Speech Recognition ◽  
Cochlear Implants ◽  
Hearing Aid ◽  
Recognition Performance ◽  
Clinical Implications ◽  
Signal To Noise ◽  
Bimodal Stimulation ◽  
Bilateral Cochlear Implants ◽  
Binaural Summation ◽  
Bimodal Condition

A meta-analytic approach was used to examine sixteen peer-reviewed publications related to speech-recognition performance in noise at fixed signal-to-noise ratios for participants who use bilateral cochlear implants (CIs) or bimodal stimulation. Two hundred eighty-seven analyses were conducted to compare the underlying contributions of binaural summation, binaural squelch, and the head-shadow effect compared to monaural conditions (CI or hearing aid). The analyses revealed an overall significant effect for binaural summation, binaural squelch, and head shadow for the bilateral and bimodal listeners relative to monaural conditions. In addition, all within-condition (bilateral or bimodal) comparisons were significant for the three binaural effects, with the exception of the bimodal condition compared to a monaural CI. No significant differences were detected between the bilateral and bimodal listeners for any of the binaural phenomena. Clinical implications and recommendations are discussed as they relate to empirical findings. Se utilizó un enfoque de meta-análisis para examinar dieciséis publicaciones con revisión editorial relacionadas con el desempeño en reconocimiento del lenguaje en medio de ruido a tasas de señal-ruido fijas, para participantes que usaban implantes cocleares bilaterales (IC) o estimulación bimodal. Se condujeron doscientos ochenta y siete análisis para comparar la contribución subyacente de la sumación bi-auricular, el chapoteo bi-auricular, y el efecto de sombra de la cabeza, en comparación con las condiciones mono-auriculares (IC y auxiliar auditivo). El análisis reveló un efecto global significativo para la sumación bi-auricular, el chapoteo bi-auricular y la sombra de la cabeza para el sujeto con audición bilateral y bimodal, en relación con las condiciones monoauriculares. Además, todas las comparaciones dentro de la misma condición (bilateral o bimodal) fueron significativas para los tres efectos bi-auriculares, con la excepción de la condición bimodal, comparada con un IC monoauricular. No se detectaron diferencias significativas entre sujetos en condición bilateral y bimodal para ninguno de los fenómenos bi-auriculares. Las implicaciones clínicas y las recomendaciones se discuten en tanto se relacionan con los hallazgos empíricos.

Selecting the Optimal FM System for Children With Cochlear Implants

2008 ◽  
Vol 18 (1) ◽  
pp. 19-24
Author(s):  
Erin C. Schafer
Keyword(s):  
Speech Recognition ◽  
Cochlear Implants ◽  
Empirical Research ◽  
Background Noise ◽  
Signal To Noise Ratio ◽  
Evidence Based ◽  
Signal To Noise ◽  
Speech Processor ◽  
System Input ◽  
Optimal Type

Children who use cochlear implants experience significant difficulty hearing speech in the presence of background noise, such as in the classroom. To address these difficulties, audiologists often recommend frequency-modulated (FM) systems for children with cochlear implants. The purpose of this article is to examine current empirical research in the area of FM systems and cochlear implants. Discussion topics will include selecting the optimal type of FM receiver, benefits of binaural FM-system input, importance of DAI receiver-gain settings, and effects of speech-processor programming on speech recognition. FM systems significantly improve the signal-to-noise ratio at the child's ear through the use of three types of FM receivers: mounted speakers, desktop speakers, or direct-audio input (DAI). This discussion will aid audiologists in making evidence-based recommendations for children using cochlear implants and FM systems.

Working Memory Capacity May Influence Perceived Effort during Aided Speech Recognition in Noise

2012 ◽  
Vol 23 (08) ◽  
pp. 577-589 ◽  
Author(s):  
Mary Rudner ◽  
Thomas Lunner ◽  
Thomas Behrens ◽  
Elisabet Sundewall Thorén ◽  
Jerker Rönnberg
Keyword(s):  
Working Memory ◽  
Hearing Loss ◽  
Speech Recognition ◽  
Hearing Aid ◽  
Recognition Performance ◽  
Cognitive Capacity ◽  
Subjective Ratings ◽  
Perceived Effort ◽  
Noise Type ◽  
Speech Recognition In Noise

Background: Recently there has been interest in using subjective ratings as a measure of perceived effort during speech recognition in noise. Perceived effort may be an indicator of cognitive load. Thus, subjective effort ratings during speech recognition in noise may covary both with signal-to-noise ratio (SNR) and individual cognitive capacity. Purpose: The present study investigated the relation between subjective ratings of the effort involved in listening to speech in noise, speech recognition performance, and individual working memory (WM) capacity in hearing impaired hearing aid users. Research Design: In two experiments, participants with hearing loss rated perceived effort during aided speech perception in noise. Noise type and SNR were manipulated in both experiments, and in the second experiment hearing aid compression release settings were also manipulated. Speech recognition performance was measured along with WM capacity. Study Sample: There were 46 participants in all with bilateral mild to moderate sloping hearing loss. In Experiment 1 there were 16 native Danish speakers (eight women and eight men) with a mean age of 63.5 yr (SD = 12.1) and average pure tone (PT) threshold of 47. 6 dB (SD = 9.8). In Experiment 2 there were 30 native Swedish speakers (19 women and 11 men) with a mean age of 70 yr (SD = 7.8) and average PT threshold of 45.8 dB (SD = 6.6). Data Collection and Analysis: A visual analog scale (VAS) was used for effort rating in both experiments. In Experiment 1, effort was rated at individually adapted SNRs while in Experiment 2 it was rated at fixed SNRs. Speech recognition in noise performance was measured using adaptive procedures in both experiments with Dantale II sentences in Experiment 1 and Hagerman sentences in Experiment 2. WM capacity was measured using a letter-monitoring task in Experiment 1 and the reading span task in Experiment 2. Results: In both experiments, there was a strong and significant relation between rated effort and SNR that was independent of individual WM capacity, whereas the relation between rated effort and noise type seemed to be influenced by individual WM capacity. Experiment 2 showed that hearing aid compression setting influenced rated effort. Conclusions: Subjective ratings of the effort involved in speech recognition in noise reflect SNRs, and individual cognitive capacity seems to influence relative rating of noise type.

The Effects of Changes in Head Angle on Auditory and Visual Input for Omnidirectional and Directional Microphone Hearing Aids

2003 ◽  
Vol 12 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Paula Henry ◽  
Todd Ricketts
Keyword(s):  
Hearing Loss ◽  
Speech Recognition ◽  
Hearing Aids ◽  
Visual Cues ◽  
Signal To Noise Ratio ◽  
Hearing Aid ◽  
Recognition Performance ◽  
Binaural Hearing ◽  
Increase Signal Intensity ◽  
Visual Mode

Improving the signal-to-noise ratio (SNR) for individuals with hearing loss who are listening to speech in noise provides an obvious benefit. Although binaural hearing provides the greatest advantage over monaural hearing in noise, some individuals with symmetrical hearing loss choose to wear only one hearing aid. The present study tested the hypothesis that individuals with symmetrical hearing loss fit with one hearing aid would demonstrate improved speech recognition in background noise with increases in head turn. Fourteen individuals were fit monaurally with a Starkey Gemini in-the-ear (ITE) hearing aid with directional and omnidirectional microphone modes. Speech recognition performance in noise was tested using the audiovisual version of the Connected Speech Test (CST v.3). The test was administered in auditory-only conditions as well as with the addition of visual cues for each of three head angles: 0°, 20°, and 40°. Results indicated improvement in speech recognition performance with changes in head angle for the auditory-only presentation mode at the 20° and 40° head angles when compared to 0°. Improvement in speech recognition performance for the auditory + visual mode was noted for the 20° head angle when compared to 0°. Additionally, a decrement in speech recognition performance for the auditory + visual mode was noted for the 40° head angle when compared to 0°. These results support a speech recognition advantage for listeners fit with one ITE hearing aid listening in a close listener-to-speaker distance when they turn their head slightly in order to increase signal intensity.

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

2009 ◽  
Vol 20 (06) ◽  
pp. 353-373 ◽  
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.

scholarly journals An Evaluation of Hearing Aid Beamforming Microphone Arrays in a Noisy Laboratory Setting

2019 ◽  
Vol 30 (02) ◽  
pp. 131-144 ◽  
Author(s):  
Erin M. Picou ◽  
Todd A. Ricketts
Keyword(s):  
Hearing Loss ◽  
Speech Recognition ◽  
Hearing Aids ◽  
Linear Models ◽  
Hearing Aid ◽  
Recognition Performance ◽  
Microphone Arrays ◽  
Laboratory Setting ◽  
Subjective Ratings ◽  
Sentence Recognition

AbstractPeople with hearing loss experience difficulty understanding speech in noisy environments. Beamforming microphone arrays in hearing aids can improve the signal-to-noise ratio (SNR) and thus also speech recognition and subjective ratings. Unilateral beamformer arrays, also known as directional microphones, accomplish this improvement using two microphones in one hearing aid. Bilateral beamformer arrays, which combine information across four microphones in a bilateral fitting, further improve the SNR. Early bilateral beamformers were static with fixed attenuation patterns. Recently adaptive, bilateral beamformers have been introduced in commercial hearing aids.The purpose of this article was to evaluate the potential benefits of adaptive unilateral and bilateral beamformers for improving sentence recognition and subjective ratings in a laboratory setting. A secondary purpose was to identify potential participant factors that explain some of the variability in beamformer benefit.Participants were fitted with study hearing aids equipped with commercially available adaptive unilateral and bilateral beamformers. Participants completed sentence recognition testing in background noise using three hearing aid settings (omnidirectional, unilateral beamformer, bilateral beamformer) and two noise source configurations (surround, side). After each condition, participants made subjective ratings of their perceived work, desire to control the situation, willingness to give up, and tiredness.Eighteen adults (50–80 yr, M = 66.2, σ = 8.6) with symmetrical mild sloping to severe hearing loss participated.Sentence recognition scores and subjective ratings were analyzed separately using generalized linear models with two within-subject factors (hearing aid microphone and noise configuration). Two benefit scores were calculated: (1) unilateral beamformer benefit (relative to performance with omnidirectional) and (2) additional bilateral beamformer benefit (relative to performance with unilateral beamformer). Hierarchical multiple linear regression was used to determine if beamformer benefit was associated with participant factors (age, degree of hearing loss, unaided speech in noise ability, spatial release from masking, and performance in omnidirectional).Sentence recognition and subjective ratings of work, control, and tiredness were better with both types of beamformers relative to the omnidirectional conditions. In addition, the bilateral beamformer offered small additional improvements relative to the unilateral beamformer in terms of sentence recognition and subjective ratings of tiredness. Speech recognition performance and subjective ratings were generally independent of noise configuration. Performance in the omnidirectional setting and pure-tone average were independently related to unilateral beamformer benefits. Those with the lowest performance or the largest degree of hearing loss benefited the most. No factors were significantly related to additional bilateral beamformer benefit.Adaptive bilateral beamformers offer additional advantages over adaptive unilateral beamformers in hearing aids. The small additional advantages with the adaptive beamformer are comparable to those reported in the literature with static beamformers. Although the additional benefits are small, they positively affected subjective ratings of tiredness. These data suggest that adaptive bilateral beamformers have the potential to improve listening in difficult situations for hearing aid users. In addition, patients who struggle the most without beamforming microphones may also benefit the most from the technology.

Effects of Adaptive Hearing Aid Directionality and Noise Reduction on Masked Speech Recognition for Children Who Are Hard of Hearing

2019 ◽  
Vol 28 (1) ◽  
pp. 101-113 ◽  
Author(s):  
Jenna M. Browning ◽  
Emily Buss ◽  
Mary Flaherty ◽  
Tim Vallier ◽  
Lori J. Leibold
Keyword(s):  
Speech Recognition ◽  
Hearing Aids ◽  
Hard Of Hearing ◽  
Signal To Noise Ratio ◽  
Hearing Aid ◽  
Normal Hearing ◽  
Signal To Noise ◽  
Open Set ◽  
Fully Adaptive ◽  
Noise Ratio

Purpose The purpose of this study was to evaluate speech-in-noise and speech-in-speech recognition associated with activation of a fully adaptive directional hearing aid algorithm in children with mild to severe bilateral sensory/neural hearing loss. Method Fourteen children (5–14 years old) who are hard of hearing participated in this study. Participants wore laboratory hearing aids. Open-set word recognition thresholds were measured adaptively for 2 hearing aid settings: (a) omnidirectional (OMNI) and (b) fully adaptive directionality. Each hearing aid setting was evaluated in 3 listening conditions. Fourteen children with normal hearing served as age-matched controls. Results Children who are hard of hearing required a more advantageous signal-to-noise ratio than children with normal hearing to achieve comparable performance in all 3 conditions. For children who are hard of hearing, the average improvement in signal-to-noise ratio when comparing fully adaptive directionality to OMNI was 4.0 dB in noise, regardless of target location. Children performed similarly with fully adaptive directionality and OMNI settings in the presence of the speech maskers. Conclusions Compared to OMNI, fully adaptive directionality improved speech recognition in steady noise for children who are hard of hearing, even when they were not facing the target source. This algorithm did not affect speech recognition when the background noise was speech. Although the use of hearing aids with fully adaptive directionality is not proposed as a substitute for remote microphone systems, it appears to offer several advantages over fixed directionality, because it does not depend on children facing the target talker and provides access to multiple talkers within the environment. Additional experiments are required to further evaluate children's performance under a variety of spatial configurations in the presence of both noise and speech maskers.

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