Using hearing aid adaptive directional microphones to enhance cochlear implant performance

Two-microphone spatial filtering provides speech reception benefits for cochlear implant users in difficult acoustic environments

“…The output SNR of a multiple-microphone array can be increased using a linear, time-invariant, combination of the microphone signals. Such fixed-processing beamformers have been demonstrated as effective noise reduction solutions for CIs (Chung et al, 2004(Chung et al, , 2006Chung and Zeng, 2009).…”

Noise reduction technologies implemented in head-worn preprocessors for improving cochlear implant performance in reverberant noise fields

“…In the past 30 years, cochlear implant hardware designs and surgical techniques have undergone many revolutions. One focus of current research is to enhance users' performance in background noise by employing signal processing algorithms to improve signal-to-noise ratios (SNRs) and to reduce noise interference (Chung et al, , 2006Spriet et al, 2007;Loizou, 2008, 2010;Chung and Zeng, 2009;Kokkinakis and Loizou, 2010). This study explored the effectiveness of a multichannel adaptive directional microphone and a modulation-based noise reduction algorithm on improving cochlear implant listeners' speech recognition ability and overall sound quality preferences in three reverberant noise fields.…”

“…Firstorder directional microphones usually consist of two omnidirectional microphones combined in subtraction mode. They are reported to be effective in enhancing speech recognition and perceived sound quality for both hearing aid and cochlear implant listeners in environments where speech comes from the front and noise comes from other directions (Chung et al, 2006;Chung and Zeng, 2009;Gifford and Revit, 2010). The average SNR improvements for hearing aid users are reported to be 3e4 dB in real-world environments for hearing aids (Valente, 1999;Ricketts, 2001;Chung, 2004).…”

“…Adaptive directional microphones are reported to be more effective than fixed-pattern directional microphones in laboratory environments with a limited number of noise sources or with dominant sources coming from focused spatial locations (Ricketts and Henry, 2002;Bentler et al, 2004;Valente and Mispagel, 2004;Spriet et al, 2007;Chung and Zeng, 2009). Advantages of adaptive-over fixed-pattern directional microphones usually diminish or disappear as the number of the noise sources increases or as the sound field becomes more diffuse (Ricketts and Henry, 2002;Bentler et al, 2004;Valente and Mispagel, 2004;Spriet et al, 2007;Chung and Zeng, 2009). In general, the higher the microphone order (i.e., more microphones/ports) and the less the number of noise sources, the higher the directional effects (Spriet et al, 2007;Chung and Zeng, 2009;Kokkinakis and Loizou, 2010).…”

Direcionalidade e redução de ruído em AASI: percepção de fala e benefício

“…The lower this association, the greater is the loss in speech understanding, both for normal hearing as well as for hard of hearing individuals 5 . New circuits present in noise reduction algorithms and directional microphones have been introduced to cochlear implants 6 and digital personal sound amplification devices (PSAD) with the intent of improving user performance 7 . Noise reduction algorithms aim at improving speech intelligibility, enhance comfort and reduce the hearing stress of PSAD users when in situations in which the S/N ratio is not favorable 8,9 .…”