02022nas a2200193   4500008004100000022001400041245012000055210006900175260001600244300001600260490000800276520139100284100001901675700001801694700002601712700002401738700001501762856005101777       2018                        eng d  a0001-496600aBottlenose dolphin ( <i>Tursiops truncatus</i>) vocal modifications in response to spectrally pink background noise0 aBottlenose dolphin iTursiops truncatusi vocal modifications in r  cJan-09-2018  a1742 - 17420 v1443 a<p>The increase of oceanic shipping is a global predicament. The resulting proliferation of underwater noise levels is a serious concern for marine mammal welfare, as it has the potential to interfere with the communicative signals of bottlenose dolphins (Tursiops truncatus). The Lombard effect and other noise-induced vocal modifications may be employed to compensate for reduced signal-to-noise ratios. This study aimed to determine which vocal modifications dolphins use during experimentally controlled background noise conditions. Three dolphins (ages 30&ndash;52) participated in behavioral hearing tests using an adaptive up-down staircase, go/no-go procedure with 15 or 40 kHz tones. Tones decreased by 3 dB increments if a dolphin responded to the tone with a conditioned whistle, and increased by 3 dB if they did not. Dolphins performed this task during ambient noise (control) conditions, as well as three elevated bandpass noise (experimental) conditions: 0.6&ndash;5 kHz (115 dB re 1 &mu;Pa) and 0.6&ndash;10 kHz (115 and 125 dB re 1 &mu;Pa). The acoustic parameters of the dolphins&rsquo; response whistles and victory squeals, such as duration, frequency, amplitude, and response latency, were analyzed and compared between control and noise conditions. These data provide a complement to field studies of odontocete noise-induced vocal modifications in the wild.</p>
1 aZapetis, Maria1 aMulsow, Jason1 aSchlundt, Carolyn, E.1 aFinneran, James, J.1 aLyn, Heidi  uhttp://asa.scitation.org/doi/10.1121/1.5067724