Subject: Re: reverse engineering of acoustic sources (Helmholtz's From: Giordano Bruno <bruno.giordano(at)UNIPD.IT> Date: Tue, 3 Feb 2004 10:54:55 +0100>Note that their sounds do not possess spectral features that can easily be >extracted for object identification. Hence, the majority of hollow objects >provide no distinct auditory cues worth learning for our cognitive system. I'd really be interested to understand on which basis the "easiness" of extraction of an auditory cue may be judged. Material categorization, and dissimilarity ratings of impulsive sounds have been shown to be influenced by a "complex" acoustical parameter called tan\phi [1] or \eta [2]. In the simpler version (tan\phi) this parameter may be roughly extracted averaging the damping factor of the spectral components (inverse of decay time), divided by half of their angular frequency. Now, although "simpler" acoustical parameters may explain the perceptual effects of this acoustical variable (spectral centroid, loudness decay velocity [2]), I wouldn't be completely sure about which is extracted more easily by the auditory system, simply because our knowledge may be incomplete. Please correct me if I'm wrong. Bruno [1] Klatzky, R. L., Pai, D. K., & Krotkov, E. P. (2000). Perception of material from contact sounds. Presence: Teleoperators and Virtual Environment, 9 (4), 399-410. [2] McAdams, S., Chaigne, A., & Roussarie, V. The psychomecanics of simulated sound sources: Material properties of impacted bars. J. Acou. Soc. Am. In Press. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Bruno L. Giordano - Ph. D. student Dipartimento di Psicologia Generale Via Venezia 8 - 35131 Padova, Italy currently hosted by KTH - Royal Institute of Technology TMH - Department of Speech, Music and Hearing Drottning Kristinas v. 31 SE-100 44 Stockholm, Sweden ------------------------------------------------- This mail sent through IMP: webmail.unipd.it