Abstract
Psychophysical experiments on amplitude-modulation (AM) masking suggest the existence of channels selectively sensitive to different ranges of modulation rates. This study investigates whether tuning depends on carrier level. Masking of a 40-Hz signal AM was measured as a function of the masker-AM rate selected from the range between 4 and 256 Hz, for Gaussian-noise and 5.5-kHz carriers. For the noise carrier, similar patterns were observed at two different spectrum levels (25 and 40 dB SPL), leading to similar estimates of the modulation-filter bandwidths. For the tonal carrier, however, tuning in AM masking varied considerably across levels. At the lowest level tested (40 dB SPL), the patterns were very broad and highly asymmetric. The patterns became more similar across carrier levels when a highpass noise was presented with the carrier. The noise limited the use of spread of excitation and thus, raised thresholds for the unmasked signal detection. The data suggest that the AM selectivity is strongly affected by the detection threshold for the unmasked AM. [Work supported by NIH grants DC00683 and DC006804.]
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
