Abstract
Frequency selectivity in the amplitude modulation (AM) domain has been demonstrated using both simultaneous AM masking and forward AM masking. This has been explained using the concept of a modulation filter bank (MFB). Here, we assessed whether the MFB occurs before or after the point of binaural interaction in the auditory pathway by using forward masking in the AM domain in an ipsilateral condition (masker AM and signal AM applied to the left ear with an unmodulated carrier in the right ear) and a contralateral condition (masker AM applied to the right ear and signal AM applied to the left ear). The carrier frequency was 8 kHz, the signal AM frequency, fs, was 40 or 80 Hz, and the masker AM frequency ranged from 0.25 to 4 times fs. Contralateral forward AM masking did occur, but it was smaller than ipsilateral AM masking. Tuning in the AM domain was slightly sharper for ipsilateral than for contralateral masking, perhaps reflecting confusion of the signal and masker AM in the ipsilateral condition when their AM frequencies were the same. The results suggest that there might be an MFB both before and after the point in the auditory pathway where binaural interaction occurs.
Highlights
It has been proposed that the outputs of the auditory filters are fed to an array of overlapping bandpass filters tuned to different envelope modulation frequencies, based on both physiological data (Schreiner and Langner, 1988) and psychophysical data (Kay, 1982; Martens, 1982; Dau et al, 1997a; 1997b; Ewert and Dau, 2000; Ewert et al., 2002; Verhey et al, 2003)
Frequencies from 100 to 500 Hz when the signal amplitude modulation (AM) was presented to the same ear as the adaptor, but not when the signal AM was presented to the opposite ear
It is possible that the lack of contralateral transfer found by Gutschalk et al (2008) reflects the high AM frequency used by them, but we found contralateral AM forward masking for an 80
Summary
It has been proposed that the outputs of the (peripheral) auditory filters are fed to an array of overlapping bandpass filters tuned to different envelope modulation frequencies, based on both physiological data (Schreiner and Langner, 1988) and psychophysical data (Kay, 1982; Martens, 1982; Dau et al, 1997a; 1997b; Ewert and Dau, 2000; Ewert et al., 2002; Verhey et al, 2003). This array of filters is usually called a “modulation filter bank”. The present experiment addressed this issue by assessing whether AM forward masking occurs when the masker AM is presented to one ear and the signal AM is presented to the other ear
Sign-in/Register to view highlights & summary 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.
