Review of the occurrence of multiple pulse echolocation clicks in recordings from small odontocetes

Finfer, D.C.; White, P.R.; Chua, Gim Hwa; Leighton, Timothy G.

doi:10.1049/iet-rsn.2011.0348

Cited by 8 publications

(4 citation statements)

References 50 publications

(74 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Pairs of pulses have been recorded from some species of dolphin, where the phase of the second is the inverse of the first, and if these were of sufficient amplitude they could be used in a TWIPS-like processing regardless of whether the dolphins generated the second pulse directly or whether it was caused by a reflection of the first pulse from the air/water interface. There was no evidence that the pulses from such species were of sufficient amplitude to generate bubble nonlinearities, and whilst some dolphins can generate pulses of sufficiently amplitude to drive bubbles nonlinearly, there was no evidence that these species generated pairs of pulses with phase inversion Finfer et al, 2012). Therefore whilst a successful sonar had been made using Γ = −1 in the above scheme to generate TWIPS, there is no hard evidence that any dolphins emit pulse trains characterized by Γ = −1.…”

Section: Do Whales Call In Spirals?mentioning

confidence: 99%

Dolphin-Inspired Target Detection for Sonar and Radar

Leighton¹,

White²

2015

Archives of Acoustics

View full text Add to dashboard Cite

Gas bubbles in the ocean are produced by breaking waves, rainfall, methane seeps, exsolution, and a range of biological processes including decomposition, photosynthesis, respiration and digestion. However one biological process that produces particularly dense clouds of large bubbles, is bubble netting. This is practiced by several species of cetacean. Given their propensity to use acoustics, and the powerful acoustical attenuation and scattering that bubbles can cause, the relationship between sound and bubble nets is intriguing. It has been postulated that humpback whales produce 'walls of sound' at audio frequencies in their bubble nets, trapping prey. Dolphins, on the other hand, use high frequency acoustics for echolocation. This begs the question of whether, in producing bubble nets, they are generating echolocation clutter that potentially helps prey avoid detection (as their bubble nets would do with manmade sonar), or whether they have developed sonar techniques to detect prey within such bubble nets and distinguish it from clutter. Possible sonar schemes that could detect targets in bubble clouds are proposed, and shown to work both in the laboratory and at sea. Following this, similar radar schemes are proposed for the detection of buried explosives and catastrophe victims, and successful laboratory tests are undertaken.

show abstract

Section: Do Whales Call In Spirals?mentioning

confidence: 99%

Dolphin-Inspired Target Detection for Sonar and Radar

Leighton¹,

White²

2015

Archives of Acoustics

View full text Add to dashboard Cite

show abstract

“…Rather than accept that such dolphins would 'blind' their most spectacular sensory apparatus when hunting, we set about proving that a previously unknown type of sonar processing (TWIPS) could detect prey in bubble nets [19,20], and showed this to work with dolphin sonar calls [21]. Although the question of whether odontocetes use such a method or not is still open to question [22,23]. Industry is now developing this to protect shipping in coastal regions such as the Persian Gulf, where clouds of bubbles and particles in the near-shore waters make mine detection difficult [ Figure 3(a)].…”

Section: Oceanic Bubble Acousticsmentioning

confidence: 99%

The acoustic bubble: Oceanic bubble acoustics and ultrasonic cleaning

Leighton¹

2015

Proceedings of Meetings on Acoustics

View full text Add to dashboard Cite

Bubbles interact strongly with sound fields. Gas bubbles in the ocean generate sound as they are produced by breaking waves, rainfall, methane seeps, etc., and such emissions can be used to size and count the bubbles present. However after production, when the pulsations of such bubbles have damped away, they are silent unless re-excited. These, and other bubbles in the ocean that do not generally make significant passive sound emissions (such as those that appear through exsolution, and a range of biological processes including decomposition, photosynthesis, respiration and digestion) can still strongly influence applied sound fields through scattering, and changing the sound speed and absorption from that which would be expected in bubble-free water. This paper discusses how these phenomena might be associated with bubble netting by cetaceans. When driven with appropriate acoustic fields, bubbles can change their surrounding environment, and examples of this are shown through the generation of cleaning in an ultrasonically-activated stream of cold water, without additives.

show abstract

“…TWIPS worked in simulation, tanks tests and finally sea trials, detecting targets in the wakes of a ferry and a commercial ship of 3953 and 4580 gross register tonnage, respectively (Leighton et al 2010(Leighton et al , 2011. However, while these TWIPS pulses were successful, there is no conclusive evidence that the types of pulses devised for that study are used by any type of dolphin (Leighton et al 2010;Finfer et al 2012). In this paper, a more general form of nonlinear mathematical processing is applied to pulses based on models of dolphin echolocation clicks.…”

Section: Introductionmentioning

confidence: 96%

Do dolphins benefit from nonlinear mathematics when processing their sonar returns?

2012

View full text Add to dashboard Cite

Dolphins have been observed to blow bubble nets when hunting prey. Such bubble nets would confound the best man-made sonar because the strong scattering by the bubbles generates 'clutter' in the sonar image, which cannot be distinguished from the true target. The engineering specification of dolphin sonar is not superior to the best man-made sonar. A logical deduction from this is that, in blowing bubble nets, either dolphins are 'blinding' their echolocation sense when hunting or they have a facility absent in man-made sonar. Here we use nonlinear mathematical functions to process the echoes of dolphin-like pulses from targets immersed in bubble clouds. Dolphins emit sequences of clicks, and, within such a sequence, the amplitude of the clicks varies. Here such variation in amplitude between clicks is exploited to enhance sonar performance. While standard sonar processing is not able to distinguish the targets from the bubble clutter, this nonlinear processing can. Although this does not conclusively prove that dolphins do use such nonlinear processing, it demonstrates that humans can detect and classify targets in bubbly water using dolphin-like sonar pulses, raising intriguing possibilities for dolphin sonar when they make bubble nets.

show abstract

Review of the occurrence of multiple pulse echolocation clicks in recordings from small odontocetes

Cited by 8 publications

References 50 publications

Dolphin-Inspired Target Detection for Sonar and Radar

Dolphin-Inspired Target Detection for Sonar and Radar

The acoustic bubble: Oceanic bubble acoustics and ultrasonic cleaning

Do dolphins benefit from nonlinear mathematics when processing their sonar returns?

Contact Info

Product

Resources

About