Re: reverse engineering of acoustic sources (Helmholtz's hollowness)

[Giordano Bruno <bruno.giordano@xxxxxxxx>]

>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

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