scholarly journals Speech Recognition in Noise in Single-Sided Deaf Cochlear Implant Recipients Using Digital Remote Wireless Microphone Technology

2019 ◽  
Vol 30 (07) ◽  
pp. 607-618 ◽  
Author(s):  
Thomas Wesarg ◽  
Susan Arndt ◽  
Konstantin Wiebe ◽  
Frauke Schmid ◽  
Annika Huber ◽  
...  

AbstractPrevious research in cochlear implant (CI) recipients with bilateral severe-to-profound sensorineural hearing loss showed improvements in speech recognition in noise using remote wireless microphone systems. However, to our knowledge, no previous studies have addressed the benefit of these systems in CI recipients with single-sided deafness.The objective of this study was to evaluate the potential improvement in speech recognition in noise for distant speakers in single-sided deaf (SSD) CI recipients obtained using the digital remote wireless microphone system, Roger. In addition, we evaluated the potential benefit in normal hearing (NH) participants gained by applying this system.Speech recognition in noise for a distant speaker in different conditions with and without Roger was evaluated with a two-way repeated-measures design in each group, SSD CI recipients, and NH participants. Post hoc analyses were conducted using pairwise comparison t-tests with Bonferroni correction.Eleven adult SSD participants aided with CIs and eleven adult NH participants were included in this study.All participants were assessed in 15 test conditions (5 listening conditions × 3 noise levels) each. The listening conditions for SSD CI recipients included the following: (I) only NH ear and CI turned off, (II) NH ear and CI (turned on), (III) NH ear and CI with Roger 14, (IV) NH ear with Roger Focus and CI, and (V) NH ear with Roger Focus and CI with Roger 14. For the NH participants, five corresponding listening conditions were chosen: (I) only better ear and weaker ear masked, (II) both ears, (III) better ear and weaker ear with Roger Focus, (IV) better ear with Roger Focus and weaker ear, and (V) both ears with Roger Focus. The speech level was fixed at 65 dB(A) at 1 meter from the speech-presenting loudspeaker, yielding a speech level of 56.5 dB(A) at the recipient's head. Noise levels were 55, 65, and 75 dB(A). Digitally altered noise recorded in school classrooms was used as competing noise. Speech recognition was measured in percent correct using the Oldenburg sentence test.In SSD CI recipients, a significant improvement in speech recognition was found for all listening conditions with Roger (III, IV, and V) versus all no-Roger conditions (I and II) at the higher noise levels (65 and 75 dB[A]). NH participants significantly benefited from the application of Roger in noise for higher levels, too. In both groups, no significant difference was detected between any of the different listening conditions at 55 dB(A) competing noise. There was also no significant difference between any of the Roger conditions III, IV, and V across all noise levels.The application of the advanced remote wireless microphone system, Roger, in SSD CI recipients provided significant benefits in speech recognition for distant speakers at higher noise levels. In NH participants, the application of Roger also produced a significant benefit in speech recognition in noise.

2015 ◽  
Vol 26 (06) ◽  
pp. 532-539 ◽  
Author(s):  
Jace Wolfe ◽  
Mila Morais ◽  
Erin Schafer

Background: Cochlear implant (CI) recipients experience difficulty understanding speech in noise. Remote-microphone technology that improves the signal-to-noise ratio is recognized as an effective means to improve speech recognition in noise; however, there are no published studies evaluating the potential benefits of a wireless, remote-microphone, digital, audio-streaming accessory device (heretofore referred to as a remote-microphone accessory) designed to deliver audio signals directly to a CI sound processor. Purpose: The objective of this study was to compare speech recognition in quiet and in noise of recipients while using their CI alone and with a remote-microphone accessory. Research Design: A two-way repeated measures design was used to evaluate performance differences obtained in quiet and in increasing levels of competing noise with the CI sound processor alone and with the sound processor paired to the remote microphone accessory. Study Sample: Sixteen users of Cochlear Nucleus 24 Freedom, CI512, and CI422 implants were included in the study. Data Collection and Analysis: Participants were evaluated in 14 conditions including use of the sound processor alone and with the remote-microphone accessory in quiet and at the following signal levels: 65 dBA speech (at the location of the participant; 85 dBA at the location of the remote microphone) in quiet and competing noise at 50, 55, 60, 65, 70, and 75 dBA noise levels. Speech recognition was evaluated in each of these conditions with one full list of AzBio sentences. Results: Speech recognition in quiet and in all competing noise levels, except the 75 dBA condition, was significantly better with use of the remote-microphone accessory compared with participants’ performance with the CI sound processor alone. As expected, in all technology conditions, performance was significantly poorer as the competing noise level increased. Conclusions: Use of a remote-microphone accessory designed for a CI sound processor provides superior speech recognition in quiet and in noise when compared with performance obtained with the CI sound processor alone.


2013 ◽  
Vol 24 (08) ◽  
pp. 714-724 ◽  
Author(s):  
Jace Wolfe ◽  
Mila Morais ◽  
Erin Schafer ◽  
Emily Mills ◽  
Hans E. Mülder ◽  
...  

Background: Previous research supports the use of frequency modulation (FM) systems for improving speech recognition in noise of individuals with cochlear implants (CIs). However, at this time, there is no published research on the potential speech recognition benefit of new digital adaptive wireless radio transmission systems. Purpose: The goal of this study was to compare speech recognition in quiet and in noise of CI recipients while using traditional, fixed-gain analog FM systems, adaptive analog FM systems, and adaptive digital wireless radio frequency transmission systems. Research Design: A three-way repeated-measures design was used to examine performance differences among devices, among speech recognition conditions in quiet and in increasing levels of background noise, and between users of Advanced Bionics and Cochlear CIs. Study Sample: Seventeen users of Advanced Bionics Harmony CI sound processors and 20 users of Cochlear Nucleus 5 sound processors were included in the study. Data Collection and Analysis: Participants were tested in a total of 32 speech-recognition-in noise-test conditions, which included one no-FM and three device conditions (fixed-gain FM, adaptive FM, and adaptive digital) at the following signal levels: 64 dBA speech (at the location of the participant) in quiet and 64 dBA speech with competing noise at 50, 55, 60, 65, 70, 75, and 80 dBA noise levels. Results: No significant differences were detected between the users of Advanced Bionics and Cochlear CIs. All of the radio frequency system conditions (i.e., fixed-gain FM, adaptive FM, and adaptive digital) outperformed the no-FM conditions in test situations with competing noise. Specifically, in conditions with 70, 75, and 80 dBA of competing noise, the adaptive digital system provided better performance than the fixed-gain and adaptive FM systems. The adaptive FM system did provide better performance than the fixed-gain FM system at 70 and 75 dBA of competing noise. At the lower noise levels of 50, 55, 60, and 65 dBA, no significant differences were detected across the three systems, and no significant differences were found across the quiet conditions. In all conditions, performance became poorer as the competing noise level increased. Conclusions: In high levels of noise, the adaptive digital system provides superior performance when compared to adaptive analog FM and fixed-gain FM systems.


Author(s):  
Sharon Miller ◽  
Jace Wolfe ◽  
Mila Duke ◽  
Erin Schafer ◽  
Smita Agrawal ◽  
...  

Abstract Background Cochlear implant (CI) recipients frequently experience difficulty understanding speech over the telephone and rely on hearing assistive technology (HAT) to improve performance. Bilateral inter-processor audio streaming technology using nearfield magnetic induction is an advanced technology incorporated within a hearing aid or CI processor that can deliver telephone audio signals captured at one sound processor to the sound processor at the opposite ear. To date, limited data exist examining the efficacy of this technology in CI users to improve speech understanding on the telephone. Purpose The primary objective of this study was to examine telephone speech recognition outcomes in bilateral CI recipients in a bilateral inter-processor audio streaming condition (DuoPhone) compared with a monaural condition (i.e., telephone listening with one sound processor) in quiet and in background noise. Outcomes in the monaural and bilateral conditions using either a telecoil or T-Mic2 technology were also assessed. The secondary aim was to examine how deactivating microphone input in the contralateral processor in the bilateral wireless streaming conditions, and thereby modifying the signal-to-noise ratio, affected speech recognition in noise. Research Design A repeated-measures design was used to evaluate speech recognition performance in quiet and competing noise with the telephone signal transmitted acoustically or via the telecoil to the ipsilateral sound processor microphone in monaural and bilateral wireless streaming listening conditions. Study Sample Nine bilateral CI users with Advanced Bionics HiRes 90K and/or CII devices were included in the study. Data Collection and Analysis The effects of phone input (monaural [DuoPhone Off] vs. bilateral [DuoPhone on]) and processor input (T-Mic2 vs. telecoil) on word recognition in quiet and noise were assessed using separate repeated-measures analysis of variance. Effect of the contralateral device mic deactivation on speech recognition outcomes for the T-Mic2 DuoPhone conditions was assessed using paired Student's t-tests. Results Telephone speech recognition was significantly better in the bilateral inter-processor streaming conditions relative to the monaural conditions in both quiet and noise. Speech recognition outcomes were similar in quiet and noise when using the T-Mic2 and telecoil in the monaural and bilateral conditions. For the acoustic DuoPhone conditions using the T-Mic2, speech recognition in noise was significantly better when the microphone of the contralateral processor was disabled. Conclusion Inter-processor audio streaming allows for bilateral listening on the telephone and produces better speech recognition in quiet and in noise compared with monaural listening conditions for adult CI recipients.


2020 ◽  
Vol 31 (06) ◽  
pp. 404-411 ◽  
Author(s):  
Linda M. Thibodeau

Abstract Background Although hearing aids (HAs) and cochlear implants (CIs) can provide significant benefits to persons with hearing loss, users frequently report difficulty hearing in noisy environments, particularly when there are multiple talkers. Little is known about the benefits provided by currently available wireless microphones in multitalker situations. Purpose The purpose of this study was to compare the benefits received in speech recognition in noise by adults with hearing loss when using two different wireless microphone types in a simulated group setting. Research Design A quasi-experimental, repeated-measures design was used where performance in a control condition, HA/CI alone, was compared with performance in two wireless microphone intervention conditions. Study Sample Participants included ten listeners, aged 20-92 years, with bilateral sensorineural hearing loss who were experienced HA or CI users. Intervention The two wireless microphones by Phonak, Roger Pen, and Roger Select used the same digital modulation protocol to transmit the signal to compatible receivers. However, the Roger Pen operated in a fixed omnidirectional mode, whereas the Roger Select operated in an adaptive directional mode. Data Collection and Analysis Participants were asked to repeat Hearing in Noise Test sentences presented in restaurant noise in three conditions: HA/CI alone, HA/CI with a Roger Pen, or HA/CI with a Roger Select microphone placed in the center of a round table. Sentences were presented from one of five loudspeakers equally spaced with the participant, while restaurant noise was presented on each side at four signal-to-noise ratios (SNRs), including +5, 0, −5, and −10 dB. A two-way, repeated-measures analysis of variance was performed with main effects of listening condition and noise level. Results Significantly  greater speech recognition performance was achieved with the wireless microphones than with listening with just the HA or CI. Furthermore, at the −5- and −10-dB SNR conditions, the Roger Select resulted in significantly better performance than the Roger Pen microphone. Conclusions The results suggest that the Roger Select microphone can provide significant benefits in speech recognition in noise over the use of HA/CI alone (61%) and also significant benefits over the use of a Roger Pen (16%) in a simulated group dining experience.


2015 ◽  
Vol 26 (05) ◽  
pp. 502-508 ◽  
Author(s):  
Jace Wolfe ◽  
Mila Morais ◽  
Erin Schafer ◽  
Smita Agrawal ◽  
Dawn Koch

Background: Cochlear implant recipients often experience difficulty with understanding speech in the presence of noise. Cochlear implant manufacturers have developed sound processing algorithms designed to improve speech recognition in noise, and research has shown these technologies to be effective. Remote microphone technology utilizing adaptive, digital wireless radio transmission has also been shown to provide significant improvement in speech recognition in noise. There are no studies examining the potential improvement in speech recognition in noise when these two technologies are used simultaneously. Purpose: The goal of this study was to evaluate the potential benefits and limitations associated with the simultaneous use of a sound processing algorithm designed to improve performance in noise (Advanced Bionics ClearVoice) and a remote microphone system that incorporates adaptive, digital wireless radio transmission (Phonak Roger). Research Design: A two-by-two way repeated measures design was used to examine performance differences obtained without these technologies compared to the use of each technology separately as well as the simultaneous use of both technologies. Study Sample: Eleven Advanced Bionics (AB) cochlear implant recipients, ages 11 to 68 yr Data Collection and Analysis: AzBio sentence recognition was measured in quiet and in the presence of classroom noise ranging in level from 50 to 80 dBA in 5-dB steps. Performance was evaluated in four conditions: (1) No ClearVoice and no Roger, (2) ClearVoice enabled without the use of Roger, (3) ClearVoice disabled with Roger enabled, and (4) simultaneous use of ClearVoice and Roger. Results: Speech recognition in quiet was better than speech recognition in noise for all conditions. Use of ClearVoice and Roger each provided significant improvement in speech recognition in noise. The best performance in noise was obtained with the simultaneous use of ClearVoice and Roger. Conclusions: ClearVoice and Roger technology each improves speech recognition in noise, particularly when used at the same time. Because ClearVoice does not degrade performance in quiet settings, clinicians should consider recommending ClearVoice for routine, full-time use for AB implant recipients. Roger should be used in all instances in which remote microphone technology may assist the user in understanding speech in the presence of noise.


2010 ◽  
Vol 21 (07) ◽  
pp. 441-451 ◽  
Author(s):  
René H. Gifford ◽  
Lawrence J. Revit

Background: Although cochlear implant patients are achieving increasingly higher levels of performance, speech perception in noise continues to be problematic. The newest generations of implant speech processors are equipped with preprocessing and/or external accessories that are purported to improve listening in noise. Most speech perception measures in the clinical setting, however, do not provide a close approximation to real-world listening environments. Purpose: To assess speech perception for adult cochlear implant recipients in the presence of a realistic restaurant simulation generated by an eight-loudspeaker (R-SPACE™) array in order to determine whether commercially available preprocessing strategies and/or external accessories yield improved sentence recognition in noise. Research Design: Single-subject, repeated-measures design with two groups of participants: Advanced Bionics and Cochlear Corporation recipients. Study Sample: Thirty-four subjects, ranging in age from 18 to 90 yr (mean 54.5 yr), participated in this prospective study. Fourteen subjects were Advanced Bionics recipients, and 20 subjects were Cochlear Corporation recipients. Intervention: Speech reception thresholds (SRTs) in semidiffuse restaurant noise originating from an eight-loudspeaker array were assessed with the subjects' preferred listening programs as well as with the addition of either Beam™ preprocessing (Cochlear Corporation) or the T-Mic® accessory option (Advanced Bionics). Data Collection and Analysis: In Experiment 1, adaptive SRTs with the Hearing in Noise Test sentences were obtained for all 34 subjects. For Cochlear Corporation recipients, SRTs were obtained with their preferred everyday listening program as well as with the addition of Focus preprocessing. For Advanced Bionics recipients, SRTs were obtained with the integrated behind-the-ear (BTE) mic as well as with the T-Mic. Statistical analysis using a repeated-measures analysis of variance (ANOVA) evaluated the effects of the preprocessing strategy or external accessory in reducing the SRT in noise. In addition, a standard t-test was run to evaluate effectiveness across manufacturer for improving the SRT in noise. In Experiment 2, 16 of the 20 Cochlear Corporation subjects were reassessed obtaining an SRT in noise using the manufacturer-suggested “Everyday,” “Noise,” and “Focus” preprocessing strategies. A repeated-measures ANOVA was employed to assess the effects of preprocessing. Results: The primary findings were (i) both Noise and Focus preprocessing strategies (Cochlear Corporation) significantly improved the SRT in noise as compared to Everyday preprocessing, (ii) the T-Mic accessory option (Advanced Bionics) significantly improved the SRT as compared to the BTE mic, and (iii) Focus preprocessing and the T-Mic resulted in similar degrees of improvement that were not found to be significantly different from one another. Conclusion: Options available in current cochlear implant sound processors are able to significantly improve speech understanding in a realistic, semidiffuse noise with both Cochlear Corporation and Advanced Bionics systems. For Cochlear Corporation recipients, Focus preprocessing yields the best speech-recognition performance in a complex listening environment; however, it is recommended that Noise preprocessing be used as the new default for everyday listening environments to avoid the need for switching programs throughout the day. For Advanced Bionics recipients, the T-Mic offers significantly improved performance in noise and is recommended for everyday use in all listening environments.


2009 ◽  
Vol 20 (07) ◽  
pp. 409-421 ◽  
Author(s):  
Jace Wolfe ◽  
Erin C. Schafer ◽  
Benjamin Heldner ◽  
Hans Mülder ◽  
Emily Ward ◽  
...  

Background: Use of personal frequency-modulated (FM) systems significantly improves speech recognition in noise for users of cochlear implants (CIs). Previous studies have shown that the most appropriate gain setting on the FM receiver may vary based on the listening situation and the manufacturer of the CI system. Unlike traditional FM systems with fixed-gain settings, Dynamic FM automatically varies the gain of the FM receiver with changes in the ambient noise level. There are no published reports describing the benefits of Dynamic FM use for CI recipients or how Dynamic FM performance varies as a function of CI manufacturer. Purpose: To evaluate speech recognition of Advanced Bionics Corporation or Cochlear Corporation CI recipients using Dynamic FM vs. a traditional FM system and to examine the effects of Autosensitivity on the FM performance of Cochlear Corporation recipients. Research Design: A two-group repeated-measures design. Participants were assigned to a group according to their type of CI. Study Sample: Twenty-five subjects, ranging in age from 8 to 82 years, met the inclusion criteria for one or more of the experiments. Thirteen subjects used Advanced Bionics Corporation, and 12 used Cochlear Corporation implants. Intervention: Speech recognition was assessed while subjects used traditional, fixed-gain FM systems and Dynamic FM systems. Data Collection and Analysis: In Experiments 1 and 2, speech recognition was evaluated with a traditional, fixed-gain FM system and a Dynamic FM system using the Hearing in Noise Test sentences in quiet and in classroom noise. A repeated-measures analysis of variance (ANOVA) was used to evaluate effects of CI manufacturer (Advanced Bionics and Cochlear Corporation), type of FM system (traditional and dynamic), noise level, and use of Autosensitivity for users of Cochlear Corporation implants. Experiment 3 determined the effects of Autosensitivity on speech recognition of Cochlear Corporation implant recipients when listening through the speech processor microphone with the FM system muted. A repeated-measures ANOVA was used to examine the effects of signal-to-noise ratio and Autosensitivity. Results: In Experiment 1, use of Dynamic FM resulted in better speech recognition in noise for Advanced Bionics recipients relative to traditional FM at noise levels of 65, 70, and 75 dB SPL. Advanced Bionics recipients obtained better speech recognition in noise with FM use when compared to Cochlear Corporation recipients. When Autosensitivity was enabled in Experiment 2, the performance of Cochlear Corporation recipients was equivalent to that of Advanced Bionics recipients, and Dynamic FM was significantly better than traditional FM. Results of Experiment 3 indicate that use of Autosensitivity improves speech recognition in noise of signals directed to the speech processor relative to no Autosensitivity. Conclusions: Dynamic FM should be considered for use with persons with CIs to improve speech recognition in noise. At default CI settings, FM performance is better for Advanced Bionics recipients when compared to Cochlear Corporation recipients, but use of Autosensitivity by Cochlear Corporation users results in equivalent group performance.


2011 ◽  
Vol 22 (02) ◽  
pp. 065-080 ◽  
Author(s):  
Alison M. Brockmeyer ◽  
Lisa G. Potts

Background: Difficulty understanding in background noise is a common complaint of cochlear implant (CI) recipients. Programming options are available to improve speech recognition in noise for CI users including automatic dynamic range optimization (ADRO), autosensitivity control (ASC), and a two-stage adaptive beamforming algorithm (BEAM). However, the processing option that results in the best speech recognition in noise is unknown. In addition, laboratory measures of these processing options often show greater degrees of improvement than reported by participants in everyday listening situations. To address this issue, Compton-Conley and colleagues developed a test system to replicate a restaurant environment. The R-SPACE™ consists of eight loudspeakers positioned in a 360 degree arc and utilizes a recording made at a restaurant of background noise. Purpose: The present study measured speech recognition in the R-SPACE with four processing options: standard dual-port directional (STD), ADRO, ASC, and BEAM. Research Design: A repeated-measures, within-subject design was used to evaluate the four different processing options at two noise levels. Study Sample: Twenty-seven unilateral and three bilateral adult Nucleus Freedom CI recipients. Intervention: The participants’ everyday program (with no additional processing) was used as the STD program. ADRO, ASC, and BEAM were added individually to the STD program to create a total of four programs. Data Collection and Analysis: Participants repeated Hearing in Noise Test sentences presented at 0 degrees azimuth with R-SPACE restaurant noise at two noise levels, 60 and 70 dB SPL. The reception threshold for sentences (RTS) was obtained for each processing condition and noise level. Results: In 60 dB SPL noise, BEAM processing resulted in the best RTS, with a significant improvement over STD and ADRO processing. In 70 dB SPL noise, ASC and BEAM processing had significantly better mean RTSs compared to STD and ADRO processing. Comparison of noise levels showed that STD and BEAM processing resulted in significantly poorer RTSs in 70 dB SPL noise compared to the performance with these processing conditions in 60 dB SPL noise. Bilateral participants demonstrated a bilateral improvement compared to the better monaural condition for both noise levels and all processing conditions, except ASC in 60 dB SPL noise. Conclusions: The results of this study suggest that the use of processing options that utilize noise reduction, like those available in ASC and BEAM, improve a CI recipient's ability to understand speech in noise in listening situations similar to those experienced in the real world. The choice of the best processing option is dependent on the noise level, with BEAM best at moderate noise levels and ASC best at loud noise levels for unilateral CI recipients. Therefore, multiple noise programs or a combination of processing options may be necessary to provide CI users with the best performance in a variety of listening situations.


2012 ◽  
Vol 23 (07) ◽  
pp. 501-509 ◽  
Author(s):  
Erin C. Schafer ◽  
Jody Pogue ◽  
Tyler Milrany

Background: Speech recognition abilities of adults and children using cochlear implants (CIs) are significantly degraded in the presence of background noise, making this an important area of study and assessment by CI manufacturers, researchers, and audiologists. However, at this time there are a limited number of fixed-intensity sentence recognition tests available that also have multiple, equally intelligible lists in noise. One measure of speech recognition, the AzBio Sentence Test, provides 10-talker babble on the commercially available compact disc; however, there is no published evidence to support equivalency of the 15-sentence lists in noise for listeners with normal hearing (NH) or CIs. Furthermore, there is limited or no published data on the reliability, validity, and normative data for this test in noise for listeners with CIs or NH. Purpose: The primary goals of this study were to examine the equivalency of the AzBio Sentence Test lists at two signal-to-noise ratios (SNRs) in participants with NH and at one SNR for participants with CIs. Analyses were also conducted to establish the reliability, validity, and preliminary normative data for the AzBio Sentence Test for listeners with NH and CIs. Research Design: A cross-sectional, repeated measures design was used to assess speech recognition in noise for participants with NH or CIs. Study Sample: The sample included 14 adults with NH and 12 adults or adolescents with Cochlear Freedom CI sound processors. Participants were recruited from the University of North Texas clinic population or from local CI centers. Data Collection and Analysis: Speech recognition was assessed using the 15 lists of the AzBio Sentence Test and the 10-talker babble. With the intensity of the sentences fixed at 73 dB SPL, listeners with NH were tested at 0 and −3 dB SNRs, and participants with CIs were tested at a +10 dB SNR. Repeated measures analysis of variance (ANOVA) was used to analyze the data. Results: The primary analyses revealed significant differences in performance across the 15 lists on the AzBio Sentence Test for listeners with NH and CIs. However, a follow-up analysis revealed no significant differences in performance across 10 of the 15 lists. Using the 10, equally-intelligible lists, a comparison of speech recognition performance across the two groups suggested similar performance between NH participants at a −3 dB SNR and the CI users at a +10 SNR. Several additional analyses were conducted to support the reliability and validity of the 10 equally intelligible AzBio sentence lists in noise, and preliminary normative data were provided. Conclusions: Ten lists of the commercial version of the AzBio Sentence Test may be used as a reliable and valid measure of speech recognition in noise in listeners with NH or CIs. The equivalent lists may be used for a variety of purposes including audiological evaluations, determination of CI candidacy, hearing aid and CI programming considerations, research, and recommendations for hearing assistive technology. In addition, the preliminary normative data provided in this study establishes a starting point for the creation of comprehensive normative data for the AzBio Sentence Test.


2008 ◽  
Vol 19 (08) ◽  
pp. 585-594 ◽  
Author(s):  
Jace Wolfe ◽  
Erin C. Schafer

Background: Use of personal frequency modulated (FM) systems significantly improves speech recognition in noise for users of cochlear implants (CI). There are, however, a number of adjustable parameters of the cochlear implant and FM receiver that may affect performance and benefit, and there is limited evidence to guide audiologists in optimizing these parameters. Purpose: This study examined the effect of two sound processor audio-mixing ratios (30/70 and 50/50) on speech recognition and functional benefit for adults with CIs using the Advanced Bionics Auria® sound processors. Research Design: Fully-repeated repeated measures experimental design. Each subject participated in every speech-recognition condition in the study, and qualitative data was collected with subject questionnaires. Study Sample: Twelve adults using Advanced Bionics Auria sound processors. Participants had greater than 20% correct speech recognition on consonant-nucleus-consonant (CNC) monosyllabic words in quiet and had used their CIs for at least six months. Intervention: Performance was assessed at two audio-mixing ratios (30/70 and 50/50). For the 50/50 mixing ratio, equal emphasis is placed on the signals from the sound processor and the FM system. For the 30/70 mixing ratio, the signal from the microphone of the sound processor is attenuated by 10 dB. Data Collection and Analysis: Speech recognition was assessed at two audio-mixing ratios (30/70 and 50/50) in quiet (35 and 50 dB HL) and in noise (+5 signal-to-noise ratio) with and without the personal FM system. After two weeks of using each audio-mixing ratio, the participants completed subjective questionnaires. Results: Study results suggested that use of a personal FM system resulted in significant improvements in speech recognition in quiet at low-presentation levels, speech recognition in noise, and perceived benefit in noise. Use of the 30/70 mixing ratio resulted in significantly poorer speech recognition for low-level speech that was not directed to the FM transmitter. There was no significant difference in speech recognition in noise or functional benefit between the two audio-mixing ratios. Conclusions: Use of a 50/50 audio-mixing ratio is recommended for optimal performance with an FM system in quiet and noisy listening situations.


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