title: Recognition of Frequency Modulated Whistle-Like Sounds by a Bottlenose Dolphin (Tursiops truncatus) and Humans with Transformations in Amplitude, Duration and Frequency.
abstract: Bottlenose dolphins (Tursiops truncatus) use the frequency contour of whistles produced by conspecifics for individual recognition. Here we tested a bottlenose dolphin's (Tursiops truncatus) ability to recognize frequency modulated whistle-like sounds using a three alternative matching-to-sample paradigm. The dolphin was first trained to select a specific object (object A) in response to a specific sound (sound A) for a total of three object-sound associations. The sounds were then transformed by amplitude, duration, or frequency transposition while still preserving the frequency contour of each sound. For comparison purposes, 30 human participants completed an identical task with the same sounds, objects, and training procedure. The dolphin's ability to correctly match objects to sounds was robust to changes in amplitude with only a minor decrement in performance for short durations. The dolphin failed to recognize sounds that were frequency transposed by plus or minus ½ octaves. Human participants demonstrated robust recognition with all acoustic transformations. The results indicate that this dolphin's acoustic recognition of whistle-like sounds was constrained by absolute pitch. Unlike human speech, which varies considerably in average frequency, signature whistles are relatively stable in frequency, which may have selected for a whistle recognition system invariant to frequency transposition.
authors: National Marine Mammal Foundation, San Diego, California, United States of America.
authors: Brian K
authors: BK
authors: Branstetter
authors: Department of Psychology, College of Liberal Arts, Rochester Institute of Technology, Rochester, New York, United States of America.
authors: Caroline M
authors: CM
authors: DeLong
authors: Department of Psychology, College of Liberal Arts, Rochester Institute of Technology, Rochester, New York, United States of America.
authors: Brandon
authors: B
authors: Dziedzic
authors: National Marine Mammal Foundation, San Diego, California, United States of America.
authors: Amy
authors: A
authors: Black
authors: National Marine Mammal Foundation, San Diego, California, United States of America.
authors: Kimberly
authors: K
authors: Bakhtiari
mesh_terms: D000162:Acoustics; D000328:Adult; D000818:Animals; D050681:Bottle-Nosed Dolphin / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009146:Music; D046709:Pattern Recognition, Physiological / Q000502:physiology*; D010897:Pitch Discrimination / Q000502:physiology*; D011597:Psychomotor Performance; D011897:Random Allocation; D013045:Species Specificity; D014828:Vocalization, Animal