Mammal Study (1998)
(...) The physical properties of the sounds produced by toothed whales are directly affected by the morphological characteristics of the air space in the head and by the sound-production mechanism…
Range-dependent flexibility in the acoustic field of view of echolocating porpoises (Phocoena phocoena)
Wisniewska, Danuta M; Ratcliffe, John M; Beedholm, Kristian; Christensen, Christian B; Johnson, Mark; Koblitz, Jens C; Wahlberg, Magnus; Madsen, Peter T
eLife (2015)
Toothed whales use sonar to detect, locate, and track prey. They adjust emitted sound intensity, auditory sensitivity and click rate to target range, and terminate prey pursuits with high-repetition-rate, low-intensity…
Acoustic gaze adjustments during active target selection in echolocating porpoises
Wisniewska, D. M.; Johnson, M.; Beedholm, K.; Wahlberg, M.; Madsen, P. T.
Journal of Experimental Biology (2012)
Visually dominant animals use gaze adjustments to organize perceptual inputs for cognitive processing. Thereby they manage the massive sensory load from complex and noisy scenes. Echolocation, as an active sensory…
Single source sound production and dynamic beam formation in echolocating harbour porpoises (Phocoena phocoena)
Madsen, P. T.; Wisniewska, D.; Beedholm, K.
Journal of Experimental Biology (2010)
Echolocating toothed whales produce high-powered clicks by pneumatic actuation of phonic lips in their nasal complexes. All non-physeteroid toothed whales have two pairs of phonic lips allowing many of these…
Keeping returns optimal: gain control exerted through sensitivity adjustments in the harbour porpoise auditory system
Linnenschmidt, M.; Beedholm, K.; Wahlberg, M.; Hojer-Kristensen, J.; Nachtigall, P. E.
Proceedings of the Royal Society B: Biological Sciences (2012)
Animals that use echolocation (biosonar) listen to acoustic signals with a large range of intensities, because echo levels vary with the fourth power of the animal's distance to the target.…
Asymmetry and dynamics of a narrow sonar beam in an echolocating harbor porpoise
Koblitz, Jens C.; Wahlberg, Magnus; Stilz, Peter; Madsen, Peter T.; Beedholm, Kristian; Schnitzler, Hans-Ulrich
The Journal of the Acoustical Society of America (2012)
A key component in the operation of a biosonar system is the radiation of sound energy from the sound producing head structures of toothed whales and microbats. The current view…
Receiving beam patterns in the horizontal plane of a harbor porpoise (Phocoena phocoena)
Kastelein, Ronald A.; Janssen, Mirjam; Verboom, Willem C.; de Haan, Dick
The Journal of the Acoustical Society of America (2005)
Receiving beam patterns of a harbor porpoise were measured in the horizontal plane, using narrow-band frequency modulated signals with center frequencies of 16, 64, and 100kHz. Total signal duration was…
Low-frequency components in harbor porpoise (Phocoena phocoena) clicks: communication signal, by-products, or artifacts?
Hansen, M.; Wahlberg, M.; Madsen, P. T.
The Journal of the Acoustical Society of America (2008)
Underwater sound signals for biosonar and communication normally have different source properties to serve the purposes of generating efficient acoustic backscatter from small objects or conveying information to conspecifics. Harbor…
Automatic Gain Control in Harbor Porpoises (Phocoena phocoena)? Central Versus Peripheral Mechanisms
Beedholm, Kristian; Miller, Lee A.
Aquatic Mammals (2007)
A previous study indicated no automatic gain control (AGC) in the auditory system of a harbor porpoise (Phocoena phocoena) as revealed by recording auditory evoked potentials to simulated echoes (Beedholm…
Auditory brainstem response in a harbor porpoise show lack of automatic gain control for simulated echoes
Beedholm, Kristian; Miller, Lee A.; Blanchet, Marie-Anne
The Journal of the Acoustical Society of America (2006)
The auditory brainstem response (ABR) response to simulated echolocation clicks was studied in a harbor porpoise, Phocoena phocoena, to determine the relationship between the animal’s perceived echo strength and the…