TY - JOUR
T1 - Bilateral Versus Unilateral Cochlear Implantation in Adult Listeners
T2 - Speech-On-Speech Masking and Multitalker Localization
AU - Rana, Baljeet
AU - Buchholz, Jörg M.
AU - Morgan, Catherine
AU - Sharma, Mridula
AU - Weller, Tobias
AU - Konganda, Shivali Appaiah
AU - Shirai, Kyoko
AU - Kawano, Atsushi
PY - 2017/7/28
Y1 - 2017/7/28
N2 - Binaural hearing helps normal-hearing listeners localize sound sources and understand speech in noise. However, it is not fully understood how far this is the case for bilateral cochlear implant (CI) users. To determine the potential benefits of bilateral over unilateral CIs, speech comprehension thresholds (SCTs) were measured in seven Japanese bilateral CI recipients using Helen test sentences (translated into Japanese) in a two-talker speech interferer presented from the front (co-located with the target speech), ipsilateral to the first-implanted ear (at +90° or −90°), and spatially symmetric at ±90°. Spatial release from masking was calculated as the difference between co-located and spatially separated SCTs. Localization was assessed in the horizontal plane by presenting either male or female speech or both simultaneously. All measurements were performed bilaterally and unilaterally (with the first implanted ear) inside a loudspeaker array. Both SCTs and spatial release from masking were improved with bilateral CIs, demonstrating mean bilateral benefits of 7.5 dB in spatially asymmetric and 3 dB in spatially symmetric speech mixture. Localization performance varied strongly between subjects but was clearly improved with bilateral over unilateral CIs with the mean localization error reduced by 27°. Surprisingly, adding a second talker had only a negligible effect on localization.
AB - Binaural hearing helps normal-hearing listeners localize sound sources and understand speech in noise. However, it is not fully understood how far this is the case for bilateral cochlear implant (CI) users. To determine the potential benefits of bilateral over unilateral CIs, speech comprehension thresholds (SCTs) were measured in seven Japanese bilateral CI recipients using Helen test sentences (translated into Japanese) in a two-talker speech interferer presented from the front (co-located with the target speech), ipsilateral to the first-implanted ear (at +90° or −90°), and spatially symmetric at ±90°. Spatial release from masking was calculated as the difference between co-located and spatially separated SCTs. Localization was assessed in the horizontal plane by presenting either male or female speech or both simultaneously. All measurements were performed bilaterally and unilaterally (with the first implanted ear) inside a loudspeaker array. Both SCTs and spatial release from masking were improved with bilateral CIs, demonstrating mean bilateral benefits of 7.5 dB in spatially asymmetric and 3 dB in spatially symmetric speech mixture. Localization performance varied strongly between subjects but was clearly improved with bilateral over unilateral CIs with the mean localization error reduced by 27°. Surprisingly, adding a second talker had only a negligible effect on localization.
KW - better-ear glimpsing
KW - bilateral benefit
KW - cochlear implants
KW - localization
KW - spatial release from masking
UR - http://www.scopus.com/inward/record.url?scp=85045838683&partnerID=8YFLogxK
UR - http://purl.org/au-research/grants/NHMRC/1056332
U2 - 10.1177/2331216517722106
DO - 10.1177/2331216517722106
M3 - Article
C2 - 28752811
AN - SCOPUS:85045838683
SN - 2331-2165
VL - 21
JO - Trends in Hearing
JF - Trends in Hearing
ER -