New model for gain control of signal intensity to object distance in echolocating bats
Echolocating bats emit ultrasonic calls and listen for the returning echoes to orient and localize prey in darkness. The emitted source level, SL (estimated signal intensity 10 cm from the mouth), is adjusted dynamically from call to call in response to sensory feedback as bats approach objects. A l...
Published in: | Journal of Experimental Biology |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2012
|
Subjects: | |
Online Access: | https://portal.findresearcher.sdu.dk/da/publications/3668586a-debd-4191-870c-e6caee0b08ab https://doi.org/10.1242/jeb.069427 |
id |
ftsydanskunivpub:oai:sdu.dk:publications/3668586a-debd-4191-870c-e6caee0b08ab |
---|---|
record_format |
openpolar |
spelling |
ftsydanskunivpub:oai:sdu.dk:publications/3668586a-debd-4191-870c-e6caee0b08ab 2024-09-15T18:39:13+00:00 New model for gain control of signal intensity to object distance in echolocating bats Nørum, Ulrik Brinkløv, Signe Surlykke, Annemarie 2012 https://portal.findresearcher.sdu.dk/da/publications/3668586a-debd-4191-870c-e6caee0b08ab https://doi.org/10.1242/jeb.069427 eng eng https://portal.findresearcher.sdu.dk/da/publications/3668586a-debd-4191-870c-e6caee0b08ab info:eu-repo/semantics/restrictedAccess Nørum , U , Brinkløv , S & Surlykke , A 2012 , ' New model for gain control of signal intensity to object distance in echolocating bats ' , Journal of Experimental Biology , vol. 215 , no. Pt 17 , pp. 3045-3054 . https://doi.org/10.1242/jeb.069427 Animals Chiroptera Echolocation Flight Animal Models Biological Regression Analysis Sound Spectrography Species Specificity Vocalization article 2012 ftsydanskunivpub https://doi.org/10.1242/jeb.069427 2024-07-22T23:48:46Z Echolocating bats emit ultrasonic calls and listen for the returning echoes to orient and localize prey in darkness. The emitted source level, SL (estimated signal intensity 10 cm from the mouth), is adjusted dynamically from call to call in response to sensory feedback as bats approach objects. A logarithmic relationship of SL=20 log(10)(x), i.e. 6 dB output reduction per halving of distance, x, has been proposed as a model for the relationship between emitted intensity and object distance, not only for bats but also for echolocating toothed whales. This logarithmic model suggests that the approaching echolocator maintains a constant intensity impinging upon the object, but it also implies ever-increasing source levels with distance, a physical and biological impossibility. We developed a new model for intensity compensation with an exponential rise to the maximum source level: SL=SL(max)-ae(-)(bx). In addition to providing a method for estimating maximum output, the new model also offers a tool for estimating a minimum detection distance where intensity compensation starts. We tested the new exponential model against the 'conventional' logarithmic model on data from five bat species. The new model performed better in 77% of the trials and as good as the conventional model in the rest (23%). We found much steeper rates of compensation when fitting the model to individual rather than pooled data, with slopes often steeper than -20 dB per halving of distance. This emphasizes the importance of analyzing individual events. The results are discussed in light of habitat constraints and the interaction between bats and their eared prey. Article in Journal/Newspaper toothed whales University of Southern Denmark Research Portal Journal of Experimental Biology 215 17 3045 3054 |
institution |
Open Polar |
collection |
University of Southern Denmark Research Portal |
op_collection_id |
ftsydanskunivpub |
language |
English |
topic |
Animals Chiroptera Echolocation Flight Animal Models Biological Regression Analysis Sound Spectrography Species Specificity Vocalization |
spellingShingle |
Animals Chiroptera Echolocation Flight Animal Models Biological Regression Analysis Sound Spectrography Species Specificity Vocalization Nørum, Ulrik Brinkløv, Signe Surlykke, Annemarie New model for gain control of signal intensity to object distance in echolocating bats |
topic_facet |
Animals Chiroptera Echolocation Flight Animal Models Biological Regression Analysis Sound Spectrography Species Specificity Vocalization |
description |
Echolocating bats emit ultrasonic calls and listen for the returning echoes to orient and localize prey in darkness. The emitted source level, SL (estimated signal intensity 10 cm from the mouth), is adjusted dynamically from call to call in response to sensory feedback as bats approach objects. A logarithmic relationship of SL=20 log(10)(x), i.e. 6 dB output reduction per halving of distance, x, has been proposed as a model for the relationship between emitted intensity and object distance, not only for bats but also for echolocating toothed whales. This logarithmic model suggests that the approaching echolocator maintains a constant intensity impinging upon the object, but it also implies ever-increasing source levels with distance, a physical and biological impossibility. We developed a new model for intensity compensation with an exponential rise to the maximum source level: SL=SL(max)-ae(-)(bx). In addition to providing a method for estimating maximum output, the new model also offers a tool for estimating a minimum detection distance where intensity compensation starts. We tested the new exponential model against the 'conventional' logarithmic model on data from five bat species. The new model performed better in 77% of the trials and as good as the conventional model in the rest (23%). We found much steeper rates of compensation when fitting the model to individual rather than pooled data, with slopes often steeper than -20 dB per halving of distance. This emphasizes the importance of analyzing individual events. The results are discussed in light of habitat constraints and the interaction between bats and their eared prey. |
format |
Article in Journal/Newspaper |
author |
Nørum, Ulrik Brinkløv, Signe Surlykke, Annemarie |
author_facet |
Nørum, Ulrik Brinkløv, Signe Surlykke, Annemarie |
author_sort |
Nørum, Ulrik |
title |
New model for gain control of signal intensity to object distance in echolocating bats |
title_short |
New model for gain control of signal intensity to object distance in echolocating bats |
title_full |
New model for gain control of signal intensity to object distance in echolocating bats |
title_fullStr |
New model for gain control of signal intensity to object distance in echolocating bats |
title_full_unstemmed |
New model for gain control of signal intensity to object distance in echolocating bats |
title_sort |
new model for gain control of signal intensity to object distance in echolocating bats |
publishDate |
2012 |
url |
https://portal.findresearcher.sdu.dk/da/publications/3668586a-debd-4191-870c-e6caee0b08ab https://doi.org/10.1242/jeb.069427 |
genre |
toothed whales |
genre_facet |
toothed whales |
op_source |
Nørum , U , Brinkløv , S & Surlykke , A 2012 , ' New model for gain control of signal intensity to object distance in echolocating bats ' , Journal of Experimental Biology , vol. 215 , no. Pt 17 , pp. 3045-3054 . https://doi.org/10.1242/jeb.069427 |
op_relation |
https://portal.findresearcher.sdu.dk/da/publications/3668586a-debd-4191-870c-e6caee0b08ab |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1242/jeb.069427 |
container_title |
Journal of Experimental Biology |
container_volume |
215 |
container_issue |
17 |
container_start_page |
3045 |
op_container_end_page |
3054 |
_version_ |
1810483614231560192 |