Effects of age on concurrent vowel perception in acoustic and simulated electroacoustic hearing.
OBJECTIVE
In this study, the authors investigated the effects of age on the use of fundamental frequency differences (ΔF(0)) in the perception of competing synthesized vowels in simulations of electroacoustic and cochlear-implant hearing.


METHODS
Twelve younger listeners with normal hearing and 13 older listeners with (near) normal hearing were evaluated in their use of ΔF(0) in the perception of competing synthesized vowels for 3 conditions: unprocessed synthesized vowels (UNP), envelope-vocoded synthesized vowels that simulated a cochlear implant (VOC), and synthesized vowels processed to simulate electroacoustic stimulation (EAS) hearing. Tasks included (a) multiplicity, which required listeners to identify whether a stimulus contained 1 or 2 sounds and (b) double-vowel identification, which required listeners to attach phonemic labels to the competing synthesized vowels.


RESULTS
Multiplicity perception was facilitated by ΔF(0) in UNP and EAS but not in VOC, with no age-related deficits evident. Double-vowel identification was facilitated by ΔF(0), with ΔF(0) benefit largest in UNP, reduced in EAS, and absent in VOC. Age adversely affected overall identification and ΔF(0) benefit on the double-vowel task.


CONCLUSIONS
Some but not all older listeners derived ΔF(0) benefit in EAS hearing. This variability may partly be due to how listeners are able to draw on higher-level processing resources in extracting and integrating cues in EAS hearing.
Arehart
Kathryn H
KH
University of Colorado at Boulder - Dept. SLHS, Campus Box 409, Boulder, Colorado 80309, USA. kathryn.arehart@colorado.edu
Souza
Pamela E
PE
Muralimanohar
Ramesh Kumar
RK
Miller
Christi Wise
CW
D000158:Acoustic Impedance Tests; D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001302:Audiometry, Speech; D003054:Cochlear Implants; D004558:Electric Stimulation; D005260:Female; D006309:Hearing / Q000502:physiology; D006801:Humans; D008297:Male; D010700:Phonetics; D011304:Presbycusis / Q000503:physiopathology* / Q000534:rehabilitation*; D013063:Speech Discrimination Tests; D013067:Speech Perception / Q000502:physiology*; D055815:Young Adult