Sound

Aversive Sounds

Some psychophysical studies have been done to assess the frequency and amplitude range of aversive sounds in rodents.

Distress Calls

Rodents may produce high pitched ultrasonic sounds, putatively to signal distress or isolation, or in response to pain, or as social warning calls. (Not necessarily due to specific vocalization system; “laryngeal braking” in rat pups causes ultrasonic squeeks, secondary to decreased body temperature, I think)

The limbic system of rodents may be tuned to these ultrasonic sounds as distress signals. PMID 17714801

Stress and Startle

Loud noise elicits a startle response. Studies of stress response evoked by auditory stimuli.

Sound as Unconditioned Stimulus

Brief neutral sounds (low amplitude pure tones or white noise) are often used as a cue or signal or conditioned stimulus (CS) in conditioning of both animals and humans. High amplitude sound or noise has also been employed as the unconditioned stimulus (US) in aversive conditioning. Loud sounds have also been used as the US in some rodent conditioning experiments.

Auditory US in Human Experiments

Loud noise is frequently used in aversive conditioning in humans,(e.g. as the US in fear conditioning) in whom the use of traditional pre-clinical USes (e.g. electric shock) would be unethical. Unpleasant sounds (metal scraping on slate) have also been used. [Loud sound was arguably the first US used in human fear conditioning as described by Watson and Rayner in the establishment of a conditioned emotional reaction in Little Albert (1920): a hammer banging on a steel bar (US) was paired with presentation of a white rat (CS); there is archival film of Albert's conditioning.

Audiogenic Seizures

There are rodent models of audiogenic seizures. [Do humans have audiogenic seizures?] Migraines in humans can be triggered by loud noises.

Sound-Induced Damage

Loud noises can cause physical damage to the cochlea and labyrinth of the inner ear.