Narrowband noise induces frequency-specific underwater temporary threshold shifts in freshwater turtles.

Freshwater turtles exhibit temporary threshold shifts (TTS) when exposed to broadband sound, but whether frequency-restricted narrowband noise induces TTS was unknown. Underwater TTS was investigated in two freshwater turtle species (Emydidae) following exposures to 16-octave narrowband noise (155-172 dB re 1 μPa2 s). While shifts occurred in all turtles at the noise center frequency (400 Hz), there were more instances of TTS and greater shift magnitudes at 12 octave above the center frequency, despite considerably lower received levels.

Frequency-dependent temporary threshold shifts in the Eastern painted turtle (Chrysemys picta picta).

Testudines are a highly threatened group facing an array of stressors, including alteration of their sensory environment. Underwater noise pollution has the potential to induce hearing loss and disrupt detection of biologically important acoustic cues and signals. To examine the conditions that induce temporary threshold shifts (TTS) in hearing in the freshwater Eastern painted turtle (Chrysemys picta picta), three individuals were exposed to band limited continuous white noise (50-1000 Hz) of varying durations and amplitudes (sound exposure levels ranged from 151 to 171 dB re 1 μPa2 s).

Temporary noise-induced underwater hearing loss in an aquatic turtle (Trachemys scripta elegans).

Noise pollution in aquatic environments can cause hearing loss in noise-exposed animals. We investigated whether exposure to continuous underwater white noise (50-1000 Hz) affects the auditory sensitivity of an aquatic turtle Trachemys scripta elegans (red-eared slider) across 16 noise conditions of differing durations and amplitudes. Sound exposure levels (SELs) ranged between 155 and 193 dB re 1 μPa2 s, and auditory sensitivity was measured at 400 Hz using auditory evoked potential methods.

Sound pressure and particle motion components of the snaps produced by two snapping shrimp species (Alpheus heterochaelis and Alpheus angulosus).

Snapping shrimps are pervasive generators of underwater sound in temperate and tropical coastal seas across oceans of the world. Shrimp snaps can act as signals to conspecifics and provide acoustic information to other species and even to humans for habitat monitoring. Despite this, there are few controlled measurements of the acoustic parameters of these abundant acoustic stimuli.