Biomaterial Database

Selectivity for harmonic structure in complex sounds by the green treefrog (Hyla cinerea). 1988

A M Simmons

Department of Psychology, Brown University, Providence, Rhode Island 02912.

1. A psychophysical technique based on reflex modification was used to study the detection of two-tone complexes in background noise by the green treefrog (Hyla cinerea). Three different two-tone complexes were synthesized and presented to measure detection thresholds--a harmonic complex of 900 + 3000 Hz (periodicity of 300 Hz, mimicking the structure of the natural advertisement call); an inharmonic complex of 830 + 3100 Hz; and a second harmonic complex of 828 + 2760 Hz (periodicity of 276 Hz). 2. Masked thresholds and 'critical ratios' (signal-to-noise ratios at threshold) were lowest for the two harmonic complexes (900 + 3000 Hz, mean 'critical ratio' of 16 dB; 828 + 2760 Hz, mean 'critical ratio' of 14 dB). For the inharmonic complex, for which there is no stable first-harmonic periodicity, the mean 'critical ratio' was 24 dB. These data suggest that the green treefrog is sensitive to the harmonic structure of complex sounds as a specific acoustic feature. 3. Because of the unique structure of the treefrog's inner ear, the heightened behavioral sensitivity to harmonic complexes must be due to processing in the central, rather than peripheral, auditory system.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D000162	Acoustics	The branch of physics that deals with sound and sound waves. In medicine it is often applied in procedures in speech and hearing studies. With regard to the environment, it refers to the characteristics of a room, auditorium, theatre, building, etc. that determines the audibility or fidelity of sounds in it. (From Random House Unabridged Dictionary, 2d ed)	Acoustic
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001001	Anura	An order of the class Amphibia, which includes several families of frogs and toads. They are characterized by well developed hind limbs adapted for jumping, fused head and trunk and webbed toes. The term "toad" is ambiguous and is properly applied only to the family Bufonidae.	Bombina,Frogs and Toads,Salientia,Toad, Fire-Bellied,Toads and Frogs,Anuras,Fire-Bellied Toad,Fire-Bellied Toads,Salientias,Toad, Fire Bellied,Toads, Fire-Bellied
D001307	Auditory Perception	The process whereby auditory stimuli are selected, organized, and interpreted by the organism.	Auditory Processing,Perception, Auditory,Processing, Auditory