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

BACKGROUND: Previous 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. PURPOSE: 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. RESEARCH DESIGN: 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. STUDY SAMPLE: Eleven adult SSD participants aided with CIs and eleven adult NH participants were included in this study. DATA COLLECTION AND ANALYSIS: 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. RESULTS: 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. CONCLUSIONS: 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.

Effect of Hearing Aid Directionality and Remote Microphone on Speech Intelligibility in Complex Listening Situations.

Remote microphones (RMs) have been developed to support hearing aid (HA) users in understanding distant talkers. In traditional clinical applications, a drawback of these systems is the deteriorated speech intelligibility in the near field. This study investigates advantages and disadvantages of clinical RM usage and the effects of different directionality settings of the HAs in complex listening situations in the laboratory. Speech intelligibility was investigated in 15 experienced severely hearing impaired participants in a noisy environment using a dual-task test paradigm where the tasks were presented from either a near field or a far field loudspeaker. Primary and secondary tasks were presented simultaneously so attention had to be shared on both tasks. In a second experiment, two speech intelligibility tests were presented from either the near field or the far field loudspeaker. The tests were interleaved to simulate a complex listening situation with shifting attention. Directional HA microphones yielded better performance than omnidirectional microphones (both combined with a RM) in near field when analyzing both tasks of the dual-task experiment separately. Furthermore, the integrated dual-task test results showed better performance with directional HA microphones compared with the omnidirectional setting (both cases in combination with a RM). These findings were confirmed by the results of the interleaved speech intelligibility test.

Speech understanding in noise with the Roger Pen, Naida CI Q70 processor, and integrated Roger 17 receiver in a multi-talker network.

Roger is a digital adaptive multi-channel remote microphone technology that wirelessly transmits a speaker's voice directly to a hearing instrument or cochlear implant sound processor. Frequency hopping between channels, in combination with repeated broadcast, avoids interference issues that have limited earlier generation FM systems. This study evaluated the benefit of the Roger Pen transmitter microphone in a multiple talker network (MTN) for cochlear implant users in a simulated noisy conversation setting. Twelve post-lingually deafened adult Advanced Bionics CII/HiRes 90K recipients were recruited. Subjects used a Naida CI Q70 processor with integrated Roger 17 receiver. The test environment simulated four people having a meal in a noisy restaurant, one the CI user (listener), and three companions (talkers) talking non-simultaneously in a diffuse field of multi-talker babble. Speech reception thresholds (SRTs) were determined without the Roger Pen, with one Roger Pen, and with three Roger Pens in an MTN. Using three Roger Pens in an MTN improved the SRT by 14.8 dB over using no Roger Pen, and by 13.1 dB over using a single Roger Pen (p < 0.0001). The Roger Pen in an MTN provided statistically and clinically significant improvement in speech perception in noise for Advanced Bionics cochlear implant recipients. The integrated Roger 17 receiver made it easy for users of the Naida CI Q70 processor to take advantage of the Roger system. The listening advantage and ease of use should encourage more clinicians to recommend and fit Roger in adult cochlear implant patients.

Evaluation of Performance With an Adaptive Digital Remote Microphone System and a Digital Remote Microphone Audio-Streaming Accessory System.

PURPOSE: One purpose of this study was to evaluate the improvement in speech recognition obtained with use of 2 different remote microphone technologies. Another purpose of this study was to determine whether a battery of audiometric measures could predict benefit from use of these technologies. METHOD: Sentence recognition was evaluated while 17 adults used each of 2 different hearing aids. Performance was evaluated with and without 2 different remote microphone systems. A variety of audiologic measures were administered to determine whether prefitting assessment may predict benefit from remote microphone technology. RESULTS: Use of both remote microphone systems resulted in improvement in speech recognition in quiet and in noise. There were no differences in performance obtained with the 2 different remote microphone technologies in quiet and at low competing noise levels, but use of the digital adaptive remote microphone system provided better speech recognition in the presence of moderate- to high-level noise. The Listening in Spatialized Noise­Sentence Test Prescribed Gain Amplifier (Cameron & Dillon, 2010) measure served as a good predictor of benefit from remote microphone technology. CONCLUSIONS: Each remote microphone system improved sentence recognition in noise, but greater improvement was obtained with the digital adaptive system. The Listening in Spatialized Noise­Sentence Test Prescribed Gain Amplifier may serve as a good indicator of benefit from remote microphone technology.

Evaluation of speech recognition of cochlear implant recipients using a personal digital adaptive radio frequency system.

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.