Detection of brief tones in noise by rats.

Four rats learned to press a lever when they heard a faint 8-kHz tone hidden in noise.

Each rat worked in a small box. A green light said "listen now." If the rat pressed within three seconds after a tone, it got a food pellet.

The team made the tone shorter and softer until each rat missed half the time. That point is the threshold.

Rats could spot tones that lasted only a few milliseconds.

Louder tones were easier to hear. Short loud tones and long soft tones worked the same if the total energy matched. This is called energy-duration reciprocity.

Each rat had its own tiny threshold, but the pattern held for all four.

Hendry et al. (1969) showed that rats trained with noise alone later ignored new light cues. The current study flips that idea: here, rats had to notice a new sound inside noise they already knew.

Burgess et al. (1971) mixed tone and light cues and saw response rates land in the middle. Boren et al. (1970) kept cues separate, proving rats can still pick out a single sound when noise is constant.

Morse et al. (1966) built the punched-tape gear that made these fine-grained measures possible. Without that 1966 tech, the 1970 thresholds could not have been tracked so cleanly.

You can borrow this yes-no setup to test sensory skills in any learner. Pick a target sound, set a clear signal, and fade the volume or length until performance drops to 50 %. The same method works for speech sounds with kids or warning buzzers with adults. It gives you a fast, objective threshold without fancy gear beyond a laptop and headphones.