Translations:Beluga whale/46/en

Every recording system imposes limits. A digital system sampled at 44.1 kHz cannot represent frequencies above approximately 22.05 kHz, and the usable limit may be lower if the hydrophone, preamplifier, or recorder rolls off earlier. A 96 kHz system has a theoretical Nyquist limit of 48 kHz, but even that does not capture the entire hearing or echolocation range reported for belugas. Older or bandwidth-limited recordings may therefore preserve the audible portion of a call while omitting ultrasonic structure. Caller identification is another difficulty: in a group, a visible animal rarely provides an obvious external cue at the instant it makes a sound.