Dolphin echo-delay resolution measured with a jittered-echo paradigm.
J Acoust Soc Am
; 148(1): 374, 2020 07.
Article
em En
| MEDLINE
| ID: mdl-32752735
ABSTRACT
Biosonar echo delay resolution was investigated in four bottlenose dolphins (Tursiops truncatus) using a "jittered" echo paradigm, where dolphins discriminated between electronic echoes with fixed delay and those whose delay alternated (jittered) on successive presentations. The dolphins performed an echo-change detection task and produced a conditioned acoustic response when detecting a change from non-jittering echoes to jittering echoes. Jitter delay values ranged from 0 to 20 µs. A passive listening task was also conducted, where dolphins listened to simulated echoes and produced a conditioned acoustic response when signals changed from non-jittering to jittering. Results of the biosonar task showed a mean jitter delay threshold of 1.3 µs and secondary peaks in error functions suggestive of the click autocorrelation function. When echoes were jittered in polarity and delay, error functions shifted by approximately 5 µs and all dolphins discriminated echoes that jittered only in polarity. Results were qualitatively similar to those from big brown bats (Eptesicus fuscus) and indicate that the dolphin biosonar range estimator is sensitive to echo phase information. Results of the passive listening task suggested that the dolphins could not passively detect changes in timing and polarity of simulated echoes.
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1
Base de dados:
MEDLINE
Assunto principal:
Quirópteros
/
Ecolocação
/
Golfinho Nariz-de-Garrafa
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article