@article {57987,
	title = {The use of seal scarers as a protective mitigation measure can induce hearing impairment in harbour porpoises},
	journal = {The Journal of the Acoustical Society of America},
	volume = {146},
	year = {2019},
	month = {Jan-12-2019},
	pages = {4288 - 4298},
	abstract = {<p>Acoustic deterrent devices (ADDs) are used to deter seals from aquacultures but exposure of harbour porpoises (Phocoena phocoena) occurs as a side-effect. At construction sites, by contrast, ADDs are used to deter harbour porpoises from the zone in which pile driving noise can induce temporary threshold shifts (TTSs). ADDs emit such high pressure levels that there is concern that ADDs themselves may induce a TTS. A harbour porpoise in human care was exposed to an artificial ADD signal with a peak frequency of 14\&thinsp;kHz. A significant TTS was found, measured by auditory evoked potentials, with an onset of 142\&thinsp;dB re 1\&thinsp;\&mu;Pa2s at 20\&thinsp;kHz and 147\&thinsp;dB re 1\&thinsp;\&mu;Pa2s at 28\&thinsp;kHz. The authors therefore strongly recommend to gradually increase and down regulate source levels of ADDs to the desired deterrence range. However, further research is needed to develop a reliable relationship between received levels and deterrence.</p>
},
	issn = {0001-4966},
	doi = {10.1121/1.5135303},
	url = {http://asa.scitation.org/doi/10.1121/1.5135303},
	author = {Schaffeld, Tobias and Ruser, Andreas and Woelfing, Benno and Baltzer, Johannes and Kristensen, Jakob H. and Larsson, Josefin and Schnitzler, Joseph G. and Siebert, Ursula}
}
