TY - JOUR AU - Beamish, Peter PY - 1974/10/01 Y2 - 2024/03/28 TI - Whale Acoustics JF - Canadian Acoustics JA - Canadian Acoustics VL - 2 IS - 4 SE - Technical Articles DO - UR - https://jcaa.caa-aca.ca/index.php/jcaa/article/view/371 SP - 8-12 AB - Hydrophone arrays have been used to record repetative sound pulses of less than a few milliseconds duration from a fin, a humpback and a blue whale. The blue whale, temporarily entrapped by ice, emitted the acoustic signals into the water from the anterior portion of its 4 meter upper jaw. The front half of this jaw is devoid of air cavities and moving muscles, hence it is unlikely that the sounds are produced there. This data, therefore, suggests that the upper jaw is an acoustic wave guide. These signals, recorded on three hydrophones at ranges 5-10 meters from the animal, as well as signals from the free swimming fin whale, recorded at ranges 10-20 meters from the animal, indicate the following peculiar directional property of the sounds. The low frequencies are beamed forward, the higher frequencies to the sides. ER -