The output from some pulsed ultrasonic transmitters commonly used in fish movement studies is faintly audible to humans. This study was undertaken to determine if the output from these and some other transmitters is detectable by Atlantic salmon (Salmo salar) parr. Classical conditioning of cardiac deceleration was attempted using the transmitter's output as the conditioned stimulus. The results from 29 experimental and 14 control fish suggest that the parr were unable to detect the output from these transmitters.
Facey DE, McCleave JD, Doyon GE. Responses of Atlantic Salmon Parr to Output of Pulsed Ultrasonic Transmitters. Transactions of the American Fisheries Society. 1977;106(5): 489-496.
publisher's version of the published document
D. E. Facey, James McCleave and G. E. Doyon. "Responses of Atlantic Salmon Parr to Output of Pulsed Ultrasonic Transmitters" Transactions of the American Fisheries Society
Vol. 106 Iss. 5 (1977) p. 489 - 496
Available at: http://works.bepress.com/james_mccleave/10/