TY - JOUR
T1 - Effect of modulation maskers on the detection of second-order amplitude modulation with and without notched noise
AU - Uchanski, Rosalie M.
AU - Moore, Brian C.J.
AU - Glasberg, Brian R.
N1 - Funding Information:
The authors thank our subjects for participating in these experiments. The first author thanks all members of the Auditory Perception Group at the University of Cambridge for the intellectual and incredibly congenial work environment. The authors also thank Christian Füllgrabe and an anonymous reviewer for helpful comments on this manuscript. This work was funded by the MRC (UK).
PY - 2006
Y1 - 2006
N2 - The mechanisms underlying the detection of second-order amplitude modulation (AM) were explored. The detectability of second-order AM (fixed depth for each subject) was measured for first- and second-order modulation rates of 16 and 2 Hz, respectively (slow-rate pair), and 50 and 10 Hz, respectively (fast-rate pair), with no masker, a low-band modulation masker (centered at 2 or 10 Hz), and a high-band modulation masker (centered at 16 or 50 Hz). This was done in the absence and presence of an audio-frequency notched noise centered at the carrier frequency of 4000 Hz. Both modulation maskers were "low-noise" noises, to prevent overmodulation. In the absence of notched noise, both modulation maskers impaired performance for the slow-rate pair, but only the low-band masker impaired performance for the fast-rate pair. When notched noise was present, the low-band masker had no significant effect for either rate pair and the high-band masker had an effect only for the slow-rate pair. These results suggest that second-order AM detection is mediated both by an envelope distortion component at the second-order rate and by slow fluctuations in the output of a modulation filter tuned to the first-order rate. When notched noise is present, the distortion component plays little role.
AB - The mechanisms underlying the detection of second-order amplitude modulation (AM) were explored. The detectability of second-order AM (fixed depth for each subject) was measured for first- and second-order modulation rates of 16 and 2 Hz, respectively (slow-rate pair), and 50 and 10 Hz, respectively (fast-rate pair), with no masker, a low-band modulation masker (centered at 2 or 10 Hz), and a high-band modulation masker (centered at 16 or 50 Hz). This was done in the absence and presence of an audio-frequency notched noise centered at the carrier frequency of 4000 Hz. Both modulation maskers were "low-noise" noises, to prevent overmodulation. In the absence of notched noise, both modulation maskers impaired performance for the slow-rate pair, but only the low-band masker impaired performance for the fast-rate pair. When notched noise was present, the low-band masker had no significant effect for either rate pair and the high-band masker had an effect only for the slow-rate pair. These results suggest that second-order AM detection is mediated both by an envelope distortion component at the second-order rate and by slow fluctuations in the output of a modulation filter tuned to the first-order rate. When notched noise is present, the distortion component plays little role.
UR - http://www.scopus.com/inward/record.url?scp=33646441171&partnerID=8YFLogxK
U2 - 10.1121/1.2188375
DO - 10.1121/1.2188375
M3 - Article
C2 - 16708951
AN - SCOPUS:33646441171
SN - 0001-4966
VL - 119
SP - 2937
EP - 2946
JO - Journal of the Acoustical Society of America
JF - Journal of the Acoustical Society of America
IS - 5
ER -