The fish is placed in the tank that is on the stand. A loudspeaker, buried in the sand, presents the sounds that are used to classically condition the fish. Psychophysical experiments on goldfish and other species are carried out using two stimulus and control systems located in one room, and two, single-person sound attenuating booths located in an adjacent room. The array processor communicates to peripheral TDT modules via fiber-optic links. All signals used are digitally synthesized.
Underwater sound is measured using calibrated hydrophones and accelerometers.
Psychophysical testing takes place in a custom-made cylindrical water tank where the fish is gently restrained in a cloth bag. The tanks rest on vibration-attenuated stone slabs inside Industrial Acoustics Corporation audiometric booths. Sound is generated by University Sound UW-30 underwater loudspeakers placed at the bottom of the test tanks. These are driven by Crown 100-Watt power amplifiers. The stimulus and control system is flexible enough to carry out fully automated experiments on detection, masking, many types of discrimination, and stimulus generalization.