The medial olivocochlear reflex in children during active listening.
OBJECTIVE
To determine if active listening modulates the strength of the medial olivocochlear (MOC) reflex in children.


METHODS
Click-evoked otoacoustic emissions (CEOAEs) were recorded from the right ear in quiet and in four test conditions: one with contralateral broadband noise (BBN) only, and three with active listening tasks wherein attention was directed to speech embedded in contralateral BBN.


METHODS
Fifteen typically-developing children (ranging in age from 8 to14 years) with normal hearing.


RESULTS
CEOAE levels were reduced in every condition with contralateral acoustic stimulus (CAS) when compared to preceding quiet conditions. There was an additional systematic decrease in CEOAE level with increased listening task difficulty, although this effect was very small. These CEOAE level differences were most apparent in the 8-18 ms region after click onset.


CONCLUSIONS
Active listening may change the strength of the MOC reflex in children, although the effects reported here are very subtle. Further studies are needed to verify that task difficulty modulates the activity of the MOC reflex in children.
Department of Speech, Language, and Hearing Sciences, University of Arizona , Tucson , USA.
Spencer B
SB
Smith
Barbara
B
Cone
D000161:Acoustic Stimulation / Q000379:methods; D000293:Adolescent; D001288:Attention; D001307:Auditory Perception / Q000502:physiology*; D002648:Child; D003051:Cochlea / Q000502:physiology*; D004525:Efferent Pathways / Q000502:physiology; D064368:Healthy Volunteers; D006801:Humans; D009622:Noise; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology*; D012018:Reflex / Q000502:physiology*; D065832:Superior Olivary Complex / Q000502:physiology*
Click-evoked otoacoustic emissions (CEOAE); attention; auditory Stroop task; contralateral inhibition; medial olivocochlear (MOC) reflex