Comparison of perceptual properties of auditory streaming between spectral and amplitude modulation domains.
The two-tone sequence (ABA_), which comprises two different sounds (A and B) and a silent gap, has been used to investigate how the auditory system organizes sequential sounds depending on various stimulus conditions or brain states. Auditory streaming can be evoked by differences not only in the tone frequency ("spectral cue": ΔFTONE, TONE condition) but also in the amplitude modulation rate ("AM cue": ΔFAM, AM condition). The aim of the present study was to explore the relationship between the perceptual properties of auditory streaming for the TONE and AM conditions. A sequence with a long duration (400 repetitions of ABA_) was used to examine the property of the bistability of streaming. The ratio of feature differences that evoked an equivalent probability of the segregated percept was close to the ratio of the Q-values of the auditory and modulation filters, consistent with a "channeling theory" of auditory streaming. On the other hand, for values of ΔFAMand ΔFTONEevoking equal probabilities of the segregated percept, the number of perceptual switches was larger for the TONE condition than for the AM condition, indicating that the mechanism(s) that determine the bistability of auditory streaming are different between or sensitive to the two domains. Nevertheless, the number of switches for individual listeners was positively correlated between the spectral and AM domains. The results suggest a possibility that the neural substrates for spectral and AM processes share a common switching mechanism but differ in location and/or in the properties of neural activity or the strength of internal noise at each level.
Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Yokohama, Kanagawa, 226-8503, Japan; Reseach Fellow of Japan Society for the Promotion of Science, Japan. Electronic address: shimpei.yamagishi@gmail.com.
Shimpei
S
Yamagishi
NTT Communication Science Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa, 243-0198, Japan. Electronic address: otsuka.s@lab.ntt.co.jp.
Sho
S
Otsuka
NTT Communication Science Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa, 243-0198, Japan. Electronic address: furukawa.shigeto@lab.ntt.co.jp.
Shigeto
S
Furukawa
NTT Communication Science Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa, 243-0198, Japan; School of Engineering, Tokyo Institute of Technology, Yokohama, Kanagawa, 226-8503, Japan. Electronic address: kashino.makio@lab.ntt.co.jp.
Makio
M
Kashino
D000161:Acoustic Stimulation; D000328:Adult; D001301:Audiometry, Pure-Tone; D001306:Auditory Pathways / Q000502:physiology*; D001307:Auditory Perception; D003463:Cues; D005260:Female; D006801:Humans; D008297:Male; D046709:Pattern Recognition, Physiological; D013997:Time Factors; D055815:Young Adult
Amplitude modulation; Auditory scene analysis; Bistable perception; Sequential organization of sounds