@article {58466, title = {In-air acoustic repertoire and associated behaviour of wild juvenile crabeater seals during rehabilitation}, journal = {Bioacoustics}, year = {2022}, month = {Aug-18-2022}, pages = {1-23}, abstract = {

In-air sounds of pinnipeds are important for interactions with conspecifics and threat displays. However, little is known about the in-air acoustic repertoire and associated behaviour of crabeater seals Lobodon carcinophaga. We investigated the in-air acoustic repertoire and associated behaviour of two male and one female wild juvenile crabeater seals that beached separately, and were rehabilitated in Durban and Gqeberha, South Africa. In-air sounds were visually identified and categorised into five classes validated via random forest model classification: brief, intermediate, and long moan calls, croaks, and hisses. Hisses were common (n\ =\ 25,105 sounds from 136 hrs of acoustic recordings) and detected during heightened arousal states and interactions with animal care staff and a conspecific. Furthermore, hisses were also recorded in low arousal states during exhalation. Moan calls (n\ =\ 241) were only detected from two of the three seals. During rehabilitation, the female seal ceased producing moan calls and later produced a series of croaks (n\ =\ 204). Acoustic characteristics of in-air moan calls differed from published underwater moan calls according to duration, minimum, and maximum frequencies, and pulse repetition rate. Our study shows that the in-air acoustic repertoire and associated behaviour of these Antarctic seals are dynamic, vary inter-individually and are context dependent.

}, issn = {0952-4622, 2165-0586}, doi = {10.1080/09524622.2022.2108145}, url = {http://dx.doi.org/10.1080/09524622.2022.2108145}, author = {Shabangu, Fannie W. and Hofmeyr, G. J. Greg and Probert, Rachel and Connan, Ma{\"e}lle and Buhrmann, Corrine A. and Gridley, Tess} } @article {58441, title = {Development and test of a bat calls detection and classification method based on convolutional neural networks}, journal = {Bioacoustics}, year = {2021}, abstract = {

Automated acoustic monitoring methods are frequently used to survey bat activity around wind turbines. The algorithms are often based on spectral features or threshold values of the recordings. Due to the generality of these features, a lot of recordings are noise, making manual analysis and labelling of the recordings time consuming. In this paper, we present an approach based on convolutional neural networks to detect and classify bat calls respectively. Recordings are converted to Mel-frequency cepstral coefficients (MFCCs), which are then fed as an image into the convolutional neural networks (CNNs) for classification. A dataset consisting of 43585 recordings gathered at 5 m height was used to train and test this method. An accuracy of 99.7\% was achieved on a test set for the binary classification of noise and bat calls. For the species classification, this approach achieved an accuracy of 96\%. Both networks, trained on data gathered at 5 m, were also tested on recordings gathered at heights of 33 m, 65 m and 95 m. In case of the binary classification task, the results showed an increased rate of misclassifications among noise recordings. For species classification, there was a higher amount of misclassifcations among all species.

}, keywords = {Bat echolocation calls, classification, convolutional neural networks, field test}, doi = {10.1080/09524622.2021.1978863}, author = {Y. Paumen and M. M{\"a}lzer and S. Alipek and J. Moll, B. L{\"u}dtke and H. Schauer-Weisshahn} } @article {53421, title = {A test of the matched filter hypothesis in two sympatric frogs, Chiromantis doriae and Feihyla vittata}, journal = {Bioacoustics}, year = {2018}, month = {Jan-06-2020}, pages = {1 - 15}, abstract = {

The matched filter hypothesis proposes that the auditory sensitivity of receivers should match the spectral energy distribution of the senders\’ signals. If so, receivers should be able to distinguish between species-specific and hetero-specific signals. We tested the matched filter hypothesis in two sympatric species, Chiromantis doriae and Feihyla vittata, whose calls exhibit similar frequency characters and that overlap in the breeding season and microenvironment. For both species, we recorded male calls and measured the auditory sensitivity of both sexes using the auditory brainstem response (ABR). We compared the auditory sensitivity with the spectral energy distribution of the calls of each species and found that (1) auditory sensitivity matched the signal spectrogram in C. doriae and F. vittata; (2) the concordance conformed better to the conspecific signal versus the hetero-specific signal. In addition, our results show that species differences are larger than sex differences for ABR audiograms.

}, keywords = {acoustic communication, auditory brainstem response, Chiromantis doriae, Feihyla vittata, interspecific interference, matched filter hypothesis}, issn = {0952-4622}, doi = {10.1080/09524622.2018.1482786}, url = {https://www.tandfonline.com/doi/full/10.1080/09524622.2018.1482786https://www.tandfonline.com/doi/pdf/10.1080/09524622.2018.1482786}, author = {Yang, Yue and Zhu, Bicheng and Wang, Jichao and Brauth, Steven E. and Tang, Yezhong and Cui, Jianguo} } @article {53365, title = {THE MECHANISM OF TUNING OF THE MOLE CRICKET SINGING BURROW}, journal = {Bioacoustics}, volume = {7}, year = {1996}, month = {Jan-01-1996}, pages = {81 - 117}, abstract = {

1.\ Experimental and theoretical studies on the acoustics of the singing burrow of the mole cricket Gryllotalpa australis are reported.


2.\ The burrow typically consists of a bulb about 26 mm long and 20 mm in diameter, connected through a constriction of diameter about 10 mm to a flaring horn with length about 40 mm and equivalent mouth diameter about 34 mm. The mouth geometry of the burrow differs from one species to another, and the aperture may be either single, double or even multiple. The end of the bulb opposite the horn connects to a narrow exit tunnei of diameter about 8 mm and length up to 1 m. The singing cricket positions itself close to the constriction between the bulb and the horn and produces a song with a frequency around 2.5 kHz.


3.\ Measurements of sound pressure within the burrow when it is excited by an external sound source at the song frequency show a pressure minimum at the constriction and an amplitude and phase distribution that is consistent with resonance of the burrow at its second modal frequency. The burrow is approximately three-quarters of a wavelength long at this frequency. The same result is obtained when the burrow is excited by a dipole source located near the constriction.


4.\ Non-parametric model calculations confirm this conclusion and also give broad agreement with the measured response curves over a frequency range from about 1.5 to 5 kHz. The calculated curves indicate an additional resonance at about 1.2 kHz associated with the first mode of the burrow\—the Helmholtz or Klipsch resonance\—which is apparently not utilised by the insect. This detail is consistent with earlier measurements, and is also supported by measured responses reported here that show an increase in sound pressure with decreasing frequency below 2 kHz as predicted by the model.


5.\ The measured performance of the burrow is broadly consistent with the model. According to the model, the burrow geometry is close to optimal for maximal sound power radiation.

}, keywords = {bioacoustics, burrow, Gryllotalpa, mole crickets, resonators, sound production}, issn = {0952-4622}, doi = {10.1080/09524622.1996.9753321}, url = {http://www.tandfonline.com/doi/abs/10.1080/09524622.1996.9753321}, author = {DAWS, A. G. and H. C. Bennet-Clark and FLETCHER, N. H.} } @article {52768, title = {Extremely divergent song types in the genus Aerotegmina Hemp (Orthoptera: Tettigoniidae: Hexacentrinae) and the description of a new species from the Eastern Arc Mountains of Tanzania (East Africa)}, journal = {Bioacoustics}, year = {2018}, month = {Feb-04-2018}, pages = {1 - 17}, abstract = {

The genus Aerotegmina comprises a group of African canopy-dwelling, predatory bushcrickets (katydids) that is known for its inflated tegmina and the unusually loud and low-frequency calling song of its type species. Here, we describe the songs of another two species of the genus which are much larger than the type species and have an even lower peak frequency. In addition, small and large species differ in song structure. While the type species and closely related forms have a broad banded, multi-peak song with strong components in the audio and ultrasonic range, the species treated here have an extremely narrow banded, resonant song with a carrier frequency of 2 kHz. With Q-values above 100 these sounds belong to the purest songs ever recorded in Orthoptera. Besides describing songs, stridulatory organs and a new species we discuss the possible functions of the song type. A key to the species of Aerotegmina is provided.

}, keywords = {Aerotegmina, bioacoustics, Eastern Arc Mountains, Orthoptera, resonant song}, issn = {0952-4622}, doi = {10.1080/09524622.2018.1443284}, url = {https://www.tandfonline.com/doi/full/10.1080/09524622.2018.1443284https://www.tandfonline.com/doi/pdf/10.1080/09524622.2018.1443284}, author = {Klaus-Gerhard Heller and Claudia Hemp} } @article {52557, title = {WHICH QS TO CHOOSE: QUESTIONS OF QUALITY IN BIOACOUSTICS?}, journal = {Bioacoustics}, volume = {9}, year = {1999}, month = {Feb-04-20122001}, pages = {351 - 359}, abstract = {

Two Q factors are in common use in bioacoustics: Q, the Quality Factor and Q10 dB. The usage, definitions and separate application of these two terms can be traced back for more than 30 years. The two terms provide different measurements of the sharpness of tuning of e.g. acoustic systems. The two terms have been used in separate contexts and they measure different things. In view of the confusion that arises from the shared use of the letter Q, it is important that whichever Q is used is defined clearly in all publications.

}, keywords = {Q, Q10 dB, Quality factor, resonance, sharpness of tuning}, issn = {0952-4622}, doi = {10.1080/09524622.1999.9753408}, url = {https://www.tandfonline.com/doi/full/10.1080/09524622.1999.9753408}, author = {H. C. Bennet-Clark} } @article {47312, title = {HABITAT ACOUSTICS OF A NEOTROPICAL LOWLAND RAINFOREST}, journal = {Bioacoustics}, volume = {13}, year = {2003}, month = {Jan-01-2003}, pages = {297 - 321}, issn = {0952-4622}, doi = {10.1080/09524622.2003.9753503}, url = {http://www.tandfonline.com/doi/abs/10.1080/09524622.2003.9753503}, author = {Norbert Ellinger and H{\"o}dl, Walter} } @article {16644, title = {Distinctive male{\textendash}female acoustic duetting supports the specific status of Isophya fatrensis , a West-Carpathian endemic bush-cricket (Insecta: Orthoptera: Tettigoniidae: Phaneropterinae)}, journal = {Bioacoustics}, year = {2017}, month = {Nov-01-2018}, pages = {1 - 14}, issn = {0952-4622}, doi = {10.1080/09524622.2016.1272005}, url = {https://www.tandfonline.com/doi/full/10.1080/09524622.2016.1272005}, author = {Ionut Stefan Iorgu and Kri{\v s}t{\'\i}n, Anton and Gergely Sz{\"o}v{\'e}nyi and Ka{\v n}uch, Peter and Jar{\v c}u{\v s}ka, Benjam{\'\i}n and Sahlean, Tiberiu Constantin and Elena Iulia Iorgu and Kirill M{\'a}rk Orci} } @article {15201, title = {The ultrasonic song of the moth Amyna natalis (Lepidoptera:Noctudidae: Acontiinae)}, journal = {Bioacoustics}, volume = {5}, year = {1993}, pages = {89-97}, chapter = {89}, abstract = {

In Malaysia, males of the noctuid moth Amyna natalis were observed producing a continuous ultrasonic song of high intensity (about 102 dB SPL measured at a distance of 10cm). The frequency spectrum of the sound impulses had its peak between 60 and 80 kHz. During song production the animals were perching on plants and moving their wings up and down quickly. Simultaneously, by twisting the wings it seems likely that a male-specific \“bubble\&$\#$39;\&$\#$39; in the forewing functions as a tymbal, resulting in sound production.

}, doi = {10.1080/09524622.1993.9753231}, url = {http://www.tandfonline.com/doi/abs/10.1080/09524622.1993.9753231}, author = {Klaus-Gerhard Heller and Achmann, Roland} } @article {12063, title = {Seewave, a free modular tool for sound analysis and synthesis}, journal = {Bioacoustics}, volume = {18}, year = {2008}, month = {Jan-01-2008}, pages = {213 - 226}, abstract = {

We review Seewave, new software for analysing and synthesizing sounds. Seewave is free and works on a wide variety of operating systems as an extension of the R operating environment. Its current 67 functions allow the user to achieve time, amplitude and frequency analyses, to estimate quantitative differences between sounds, and to generate new sounds for playback experiments. Thanks to its implementation in the R environment, Seewave is fully modular. All functions can be combined for complex data acquisition and graphical output, they can be part of important scripts for batch processing and they can be modified ad libitum. New functions can also be written, making Seewave a truly open-source tool.

}, issn = {0952-4622}, doi = {10.1080/09524622.2008.9753600}, url = {http://www.tandfonline.com/doi/abs/10.1080/09524622.2008.9753600}, author = {Sueur, Jerome and Aubin, Thierry and Simonis, Caroline} } @article {11175, title = {Ultrasonic reverse stridulation in the spider-like katydid Arachnoscelis (Orthoptera: Listrosceledinae)}, journal = {Bioacoustics}, volume = {23}, year = {2014}, month = {Feb-01-2014}, pages = {67 - 77}, abstract = {

This paper illustrates the biomechanics of sound production in the neotropical predaceous katydid Arachnoscelis arachnoides (Insecta: Orthoptera: Tettigoniidae). Described and previously known from only one male specimen, this genus of predaceous katydids resembles spiders in their general body appearance. To call distant females, male katydids produce songs by stridulation where one forewing possessing a sclerotized file rubs against a row of teeth (scraper) on the other wing. In most katydid species, the songs are produced during the wing-closing phase of the stridulation. Morphological comparative studies of the stridulatory apparatus of the type specimen of Arachnoscelis arachnoides and males of other closely related species suggest that this insect sings with a frequency of ca. 80 kHz to attract conspecific females. We found an abundant population of A. arachnoides in Central Northeast of Colombia and undertook a complete analysis of the biomechanics of stridulation in this species. Using ultrasound-sensitive equipment and high-speed video, we determined that male A. arachnoides sing at ca. 74 kHz and use elastic energy and wing deformation to reach such ultrasonic frequencies. In contrast to most katydids, males of this species produce their calls during the opening phase of the wing; this form of stridulation is discussed.

}, keywords = {biomechanics, Colombia, elastic energy, stridulation, ultrasound}, issn = {0952-4622}, doi = {10.1080/09524622.2013.816639}, url = {http://www.tandfonline.com/doi/abs/10.1080/09524622.2013.816639}, author = {Benedict D. Chivers and Jonsson, Thorin and Cadena-Castaneda, Oscar J. and Fernando Montealegre-Zapata} }