Editing Pygmy killer whale (section)

== Echolocation and hearing ==
[[File:Pygmy killer whale necropsy.jpg|thumb|left|Necropsy of two pygmy killer whales by [[NOAA]] scientists.]]
Like other oceanic dolphins, pygmy killer whales use [[Animal echolocation|echolocation]]. The [[Spectral centroid|centroid]] of echolocation frequencies is between 70–85&nbsp;kHz and can range from 32 to 100&nbsp;kHz. This is similar to the range of other odontocetes such as the bottlenose dolphin but is slightly higher than false killer whales. While echolocating, they produce 8-20 clicks per second with a 197-223 decibel sound level at the production source. The linear directionality of sound production in pygmy killer whales is better than in porpoises but lower than is found in bottlenose dolphins; higher directionality results in sounds that are easier to discern from background noise. Based on similarities to the acoustic parameters of other odontocetes, it is presumed that they use a similar mechanism for producing echolocation clicks.<ref>{{Cite journal|title = Source parameter estimates of echolocation clicks from wild pygmy killer whales (Feresa attenuata) (L)|last1 = Madsen|first1 = P. T.|date = 2004|journal = Journal of the Acoustical Society of America|doi = 10.1121/1.1788726 |pmid = 15532623| first2 = I. | last2 = Kerr | first3 = R. | last3 = Payne | volume=116 |issue = 4| pages=1909–1912| bibcode=2004ASAJ..116.1909M }}</ref>

The anatomy for auditory reception is similar to other odontocetes, with a hollow [[mandible]] and a mandibular fat body composed of a low density outer layer and a denser inner core. The inner core comes into direct contact with the tympanoperiotic complex (functionally similar to the [[Tympanic part of the temporal bone|auditory bulla]] in other species - see [[Cetacea#Ears|Cetacea]]). Hearing tests performed on two live individuals brought in for rehabilitation exhibited frequency response range and temporal resolution similar to that found in other echolocating dolphins. During those tests, one individual exhibited low frequency hearing loss that might have been related to treatment with the antibiotic [[amikacin]] although the researchers believed the more likely cause was slight differences in testing setup.<ref>{{Cite journal|last1=Montie|first1=Eric W.|last2=Manire|first2=Charlie A.|last3=Mann|first3=David A.|date=2011-03-15|title=Live CT imaging of sound reception anatomy and hearing measurements in the pygmy killer whale, Feresa attenuata|journal=Journal of Experimental Biology|language=en|volume=214|issue=6|pages=945–955|doi=10.1242/jeb.051599|issn=0022-0949|pmid=21346122|doi-access=free|bibcode=2011JExpB.214..945M }}</ref>