Directional benefit in simulated classroom environments.
OBJECTIVE
To examine speech recognition performance and subjective ratings for directional and omnidirectional microphone modes across a variety of simulated classroom environments.


METHODS
Speech recognition was measured in a group of 26 children age 10-17 years in up to 8 listening environments.


RESULTS
Significant directional benefit was found when the sound source(s) of interest was in front, and directional decrement was measured when the sound source of interest was behind the participants. Of considerable interest is that a directional decrement was observed in the absence of directional benefit when sources of interest were both in front of and behind the participants. In addition, limiting directional processing to the low frequencies eliminated both the directional deficit and the directional advantage.


CONCLUSIONS
Although these data support the use of directional hearing aids in some noisy school environments, they also suggest that use of the directional mode should be limited to situations in which all talkers of interest are located in the front hemisphere. These results highlight the importance of appropriate switching between microphone modes in the school-age population.
Dan Maddox Hearing Aid Research Laboratory, Vanderbilt University Medical Center, Department of Hearing and Speech Sciences, 1215 21st Avenue South, Room 8310, Medical Center East, South Tower, Nashville, TN 37232-8242, USA. todd.a.ricketts@vanderbilt.edu
Todd
T
Ricketts
Jason
J
Galster
Anne Marie
AM
Tharpe
D000293:Adolescent; D002648:Child; D004777:Environment; D005260:Female; D006310:Hearing Aids; D006311:Hearing Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy*; D006801:Humans; D008297:Male