The effect of signal onset/offset envelope on underwater detection thresholds of a harbor seal (Phoca vitulina).
The effects of signal onset/offset envelope on the underwater hearing thresholds of a harbor seal (Phoca vitulina) were measured. Pure-tone, 540-ms pulses at 2, 4, 8, and 16 kHz were presented as test signals. An ANOVA revealed that there were no significant differences between repeated threshold measures for abrupt onset/offset signal envelopes versus slow onset/offset signal envelopes [F = 4.380, d.f. = (1,18), p > 0.05]. Seal vocalizations which have an abrupt onset/offset may be serving a short-range communicative function by helping the listener determine the direction of a nearby sender.
Turnbull
S D
SD
Department of Biology, University of New Brunswick, Saint John, Canada.
Terhune
J M
JM
D000818:Animals; D001309:Auditory Threshold; D004867:Equipment Design; D006309:Hearing / Q000502:physiology; D008297:Male; D046048:Seals, Earless / Q000502:physiology*; D017603:Signal Detection, Psychological