Modeling of the dolphin’s clicking sound source: The influence of the critical parameters

Dubrovsky, N. A.; Gladilin, A. V.; Møhl, Bertel; Wahlberg, Magnus

doi:10.1134/1.1776225

Cited by 8 publications

(5 citation statements)

References 10 publications

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“…The current understanding of click production in odontocetes is that air pressure builds up ventral to the phonic lips, which are located a few centimeters below the blow hole in the harbor porpoise (Amundin, 1991;Cranford et al, 1995). Dubrovsky et al (2004) elaborated on an earlier model of click production that incorporates an expandable ring (sphincter) displaced by excessive air pressure when a click is produced. They presented convincing evidence that the model can be applied to click production in odontocetes.…”

Section: Discussionmentioning

confidence: 99%

Automatic Gain Control in Harbor Porpoises (<I>Phocoena phocoena</I>)? Central Versus Peripheral Mechanisms

Beedholm¹,

Miller²

2007

aquatic mammals

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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 et al., 2006). The same harbor porpoise did change the rate and amplitude of its echolocation clicks during stationary echolocation when presented with an artificial target at a fixed delay. The animal spontaneously changed its click rate in such a way that the emitted level (in dB, arbitrary reference) of a click decreased as the inter-click interval (ICI) decreased (click emission rate increases), according to a 14.5 log (ICI) function. This same relationship was found when the animal swam toward a target (a fish). It reduced the amplitude of its clicks as it approached the target with a-14 to-17 log R (best-fit), which is close to the expected-20 log R found in other studies. The combined results indicate an incomplete AGC working on the transmitter side and might be explained by constraints in the sound production apparatus that couple the sound amplitude to the click rate.

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Section: Discussionmentioning

confidence: 99%

Automatic Gain Control in Harbor Porpoises (<I>Phocoena phocoena</I>)? Central Versus Peripheral Mechanisms

Beedholm¹,

Miller²

2007

aquatic mammals

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“…After respiration, the second important function of the nasal complex in toothed whales is the generation and transmission of echolocation clicks and communication sounds (Norris & Harvey, 1974;Cranford et al, 2000;Cranford & Amundin, 2004;Au et al, 2006;Madsen et al, 2010). For sound generation, toothed whales have specific valves (monkey lips ¼ phonic lips) associated with small fat bodies (dorsal bursae ¼ bursae cantantes), which can vibrate in the air current and generate sound waves in adjacent tissues (Cranford, 1988;Cranford et al, 1996;Dubrovsky et al, 2004;Huggenberger et al, 2009). These sounds (i.e.…”

Section: Introductionmentioning

confidence: 99%

The nose of the sperm whale: overviews of functional design, structural homologies and evolution

2014

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The hypertrophic and much elongated epicranial (nasal) complex of sperm whales (Physeter macrocephalus) is a unique device to increase directionality and source levels of echolocation clicks in aquatic environments. The size and shape of the nasal fat bodies as well as the peculiar organization of the air sac system in the nasal sound generator of sperm whales are in favour of this proposed specialized acoustic function. The morphology of the sperm whale nose, including a 'connecting acoustic window' in the case and an anterior 'terminal acoustic window' at the rostroventral edge of the junk, supports the 'bent horn hypothesis' of sound emission. In contrast to the laryngeal mechanism described for dolphins and porpoises, sperm whales may drive the initial pulse generation process with air pressurized by nasal muscles associated with the right nasal passage (right nasal passage muscle, maxillonasolabialis muscle). This can be interpreted as an adaptation to deep-diving and high hydrostatic pressures constraining pneumatic phonation. Comparison of nasal structures in sperm whales and other toothed whales reveals that the existing air sac system as well as the fat bodies and the musculature have the same topographical relations and thus may be homologous in all toothed whales (Odontoceti). This implies that the nasal sound generating system evolved only once during toothed whale evolution and, more specifically, that the unique hypertrophied nasal complex was a main driving force in the evolution of the sperm whale taxon.

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“…The current understanding is that echolocation clicks are generated by pneumatic actuation of pairs of phonic lips that couple sound energy into the water via the fatty melon (Ridgway et al, 1980;Cranford, 2000, Madsen et al, 2002. When a small volume of pressurized air moves from the nasopharyngeal sac to the vestibular air sacs via regulation of the nasal plugs (Ridgway and Carder, 1988), the phonic lips will be accelerated whereby the click is generated (Cranford et al, 1996;Cranford and Amundin, 2003;Dubrovsky et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Single source sound production and dynamic beam formation in echolocating harbour porpoises (Phocoena phocoena)

Madsen

Wisniewska

Beedholm

2010

Journal of Experimental Biology

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SUMMARYEcholocating 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 species to produce both whistles and clicks at the same time. That has led to the hypothesis that toothed whales can increase the power outputs and bandwidths of clicks, and enable fast clicking and beam steering by acutely timed actuation of both phonic lip pairs simultaneously. Here we test that hypothesis by applying suction cup hydrophones on the sound-producing nasal complexes of three echolocating porpoises (Phocoena phocoena) with symmetrical pairs of phonic lips. Using time of arrival differences on three hydrophones, we show that all recorded clicks from these three porpoises are produced by the right pair of phonic lips with no evidence of simultaneous or independent actuation of the left pair. It is demonstrated that porpoises, despite actuation of only one sound source, can change their output and sound beam probably through conformation changes in the sound-producing soft tissues and nasal sacs, and that the coupling of the phonic lips and the melon acts as a waveguide for sound energy between 100 and 160kHz to generate a forward-directed sound beam for echolocation.

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Modeling of the dolphin’s clicking sound source: The influence of the critical parameters

Cited by 8 publications

References 10 publications

Automatic Gain Control in Harbor Porpoises (<I>Phocoena phocoena</I>)? Central Versus Peripheral Mechanisms

Automatic Gain Control in Harbor Porpoises (<I>Phocoena phocoena</I>)? Central Versus Peripheral Mechanisms

The nose of the sperm whale: overviews of functional design, structural homologies and evolution

Single source sound production and dynamic beam formation in echolocating harbour porpoises (Phocoena phocoena)

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