Brief report: Occurrence of anti-resonance in the song of the siamang (Hylobates syndactylus)


  • Dr. Elliott H. Haimoff

    Corresponding author
    1. Sub-Department of Veterinary Anatomy, University of Cambridge, Cambridge, England
    • Anthropology Department, University of California at Los Angeles, Los Angeles 90024
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The duetting behavior of siamangs (Hylobates syndactylus) has previously been observed as representing a complex, interactively organized, and standardized set of vocal features. Anti-resonance in the bitonal screams of 15 males was observed. The sound energy of the fundamental frequency of the first note of these screams are absorbed, the result being a fundamental frequency which was virtually filtered out. The implications and consequences of such a rare phenomenon as anti-resonance in the vocal behavior in gibbons is discussed.