Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Estimates of compression at low and high frequencies using masking additivity in normal and impaired ears
AU - Plack, Christopher J.
AU - Oxenham, Andrew J.
AU - Simonson, Andrea M.
AU - O'Hanlon, Catherine G.
AU - Drga, Vit
AU - Arifianto, Dhany
PY - 2008/6
Y1 - 2008/6
N2 - Auditory compression was estimated at 250 and 4000 Hz by using the additivity of forward masking technique, which measures the effects on signal threshold of combining two temporally nonoverlapping forward maskers. The increase in threshold in the combined-masker condition compared to the individual-masker conditions can be used to estimate compression. The signal was a 250 or 4000 Hz tone burst and the maskers (M1 and M2) were bands of noise. Signal thresholds were measured in the presence of M I and M2 alone and combined for a range of masker levels. The results were used to derive response functions at each frequency. The procedure was conducted with normal-hearing and hearing-impaired listeners. The results suggest that the response function in normal ears is similar at 250 and 4000 Hz with a mid level compression exponent of about 0.2. However, compression extends over a smaller range of levels at 250 Hz. The results confirm previous estimates of compression using temporal masking curves (TMCs) without assuming a linear off-frequency reference as in the TMC procedure. The impaired ears generally showed less compression. Importantly, some impaired ears showed a linear response at 250 Hz, providing a further indication that low-frequency compression originates in the cochlea.
AB - Auditory compression was estimated at 250 and 4000 Hz by using the additivity of forward masking technique, which measures the effects on signal threshold of combining two temporally nonoverlapping forward maskers. The increase in threshold in the combined-masker condition compared to the individual-masker conditions can be used to estimate compression. The signal was a 250 or 4000 Hz tone burst and the maskers (M1 and M2) were bands of noise. Signal thresholds were measured in the presence of M I and M2 alone and combined for a range of masker levels. The results were used to derive response functions at each frequency. The procedure was conducted with normal-hearing and hearing-impaired listeners. The results suggest that the response function in normal ears is similar at 250 and 4000 Hz with a mid level compression exponent of about 0.2. However, compression extends over a smaller range of levels at 250 Hz. The results confirm previous estimates of compression using temporal masking curves (TMCs) without assuming a linear off-frequency reference as in the TMC procedure. The impaired ears generally showed less compression. Importantly, some impaired ears showed a linear response at 250 Hz, providing a further indication that low-frequency compression originates in the cochlea.
KW - BASILAR-MEMBRANE NONLINEARITY
KW - SENSORINEURAL HEARING-LOSS
KW - INPUT-OUTPUT FUNCTIONS
KW - GUINEA-PIG COCHLEA
KW - CHINCHILLA COCHLEA
KW - PERIPHERAL COMPRESSION
KW - TEMPORAL SUMMATION
KW - AUDITORY COMPRESSION
KW - IN-VIVO
KW - LISTENERS
U2 - 10.1121/1.2908297
DO - 10.1121/1.2908297
M3 - Journal article
VL - 123
SP - 4321
EP - 4330
JO - Journal of the Acoustical Society of America
JF - Journal of the Acoustical Society of America
SN - 0001-4966
IS - 6
ER -