@article {57600,
	title = {Long-term evidence of noise-induced permanent threshold shift in a harbor seal ( <i>Phoca vitulina</i>               )},
	year = {2019},
	abstract = {<p>In psychophysical studies of noise-induced hearing loss with marine mammals, exposure conditions are often titrated from levels of no effect to those that induce significant but recoverable loss of auditory sensitivity [temporary threshold shift (TTS)]. To examine TTS from mid-frequency noise, a harbor seal was exposed to a 4.1-kHz underwater tone that was incrementally increased in sound pressure level (SPL) and duration. The seal\&$\#$39;s hearing was evaluated at the exposure frequency and one-half octave higher (5.8\&thinsp;kHz) to identify the noise parameters associated with TTS onset. No reliable TTS was measured with increasing sound exposure level until the second exposure to a 60-s fatiguing tone of 181\&thinsp;dB re 1 \&mu;Pa SPL (sound exposure level 199\&thinsp;dB re 1 \&mu;Pa2s), after which an unexpectedly large threshold shift (\&gt;47\&thinsp;dB) was observed. While hearing at 4.1\&thinsp;kHz recovered within 48\&thinsp;h, there was a permanent threshold shift of at least 8\&thinsp;dB at 5.8\&thinsp;kHz. This hearing loss was evident for more than ten years. Furthermore, a residual threshold shift of 11\&thinsp;dB was detected one octave above the tonal exposure, at 8.2\&thinsp;kHz. This hearing loss persisted for more than two years prior to full recovery.</p>
},
	doi = {10.1121/1.5129379},
	url = {http://asa.scitation.org/doi/10.1121/1.5129379},
	author = {Reichmuth, Colleen and Jillian M. Sills and Mulsow, Jason and Ghoul, Asila}
}
