Aural Discrimination of Targets by Human Subjects Using Broadband Sonar Pulses
Abstract
Sonar echo discrimination experiments were conducted with human subjects, using targets employed in a dolphin echo-recognition study. Digital recordings of the target echoes were obtained using a dolphin-like echolocation signal with a peak-frequency of 122 kHz, and were played back to the subject at 1/50 of the original sample rate. Targets included hollow cylinders of aluminum, bronze, steel and glass having diameters of 3.81 and 7.62 cm, and a solid 7.62- cm aluminum cylinder. All targets were 17.78 cm in length. Echo amplitudes were adjusted so that stimulus intensity was not a cue. The subjects discriminated between echoes from (1) solid and hollow, and (2) small and large aluminum cylinders with correct responses of 98% and 92%, respectively, after one session per task. Correct responses for the aluminum-bronze and the aluminum-steel discriminations were 98% and 95%, respectively. Correct responses for the aluminum-glass discrimination varied between 72% and 98%. Differences in time- separation-pitch associated with correlated echo highlights and differences in echo duration were the predominant discrimination cues.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1982
- Accession Number
- ADA123466
Entities
People
- D. W. Martin
- W. W. L. Au