title: Underwater Equal-Latency Contours of a Harbor Porpoise (Phocoena phocoena) for Tonal Signals Between 0.5 and 125 kHz.
abstract: Loudness perception can be studied based on the assumption that sounds of equal loudness elicit equal reaction time (RT; or "response latency"). We measured the underwater RTs of a harbor porpoise to narrowband frequency-modulated sounds and constructed six equal-latency contours. The contours paralleled the audiogram at low sensation levels (high RTs). At high-sensation levels, contours flattened between 0.5 and 31.5 kHz but dropped substantially (RTs shortened) beyond those frequencies. This study suggests that equal-latency-based frequency weighting can emulate noise perception in porpoises for low and middle frequencies but that the RT-loudness correlation is relatively weak for very high frequencies.
authors.affiliation: Sea Mammal Research Unit, Scottish Oceans Institute, University of St. Andrews, Bute Building, St. Andrews, Fife, KY16 8LB, UK. pw234@st-andrews.ac.uk.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Wensveen
authors.affiliation: Sea Mammal Research Company (SEAMARCO), Inc., Harderwijk, 3843, CC, The Netherlands. leonie.huijser@gmail.com.
authors.forename: Léonie A E
authors.initials: LA
authors.lastname: Huijser
authors.affiliation: Sea Mammal Research Company (SEAMARCO), Inc., Harderwijk, 3843, CC, The Netherlands. leanhoek@hotmail.com.
authors.forename: Lean
authors.initials: L
authors.lastname: Hoek
authors.affiliation: Sea Mammal Research Company (SEAMARCO), Inc., Harderwijk, 3843, CC, The Netherlands. researchteam@zonnet.nl.
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Kastelein
mesh_terms: D000818:Animals; D050741:Phocoena / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D012623:Seawater; D013016:Sound
keywords: Auditory weighting; Loudness; Noise effects; Odontocetes; Reaction time