• Michael Stocker added an answer:
    Should i use dBPeak values to determine underwater noise mitigation for marine mammals (i.e., safety zones)?

    Should i use dBPeak values to determine underwater noise mitigation (i.e., safety zones) instead of dBrms even though the NMFS interim sound thresholds for marine mammals uses dBrms? As thresholds are considered absolute values we should not exceed (e.g., to avoid TTS and PTS), should we monitor for dBPeak values instead of dBrms? This is in relation to impulsive sound rather than continuous sounds.

    Michael Stocker
    Willem is correct. There are so many other variables than just how loud something is. He's done some great work on this. Also see our "Signal kurtosis as a predictor of biological impacts of noise exposure:
    There are some other simple metrics that express cumulative noise exposure using RMS but whether and how you use a time integral hinges on a number a factors including the hearing frequency response of the exposed animal in question.
  • Adel M. Badawy added an answer:
    What is the vocal tract length of Felis catus domesticus?

    Does anyone by chance know a good reference for the vocal tract length of domestic cats?

  • Melanie Sandra James added an answer:
    Have playback calls be used to measure amphibian populations?

    I've recently used the calls of male midwife toads played back to a restricted population of the toads in order to assess their overall population size. Has anything like this been done in the past within Europe either with midwife toads or another anuran species?

    Melanie Sandra James

    Hi Steven,

    There are some other climate/weather variables which may be useful to record. Although the paper is not from Europe, I thought it might help provide some other variables to record. There are a lot of things that will influence calling and therefore detectability and I'm trying to explore that for my species now. Good luck.

  • Miłosz Grabowski added an answer:
    What is the best available probe/way to measure particle motion (velocity/acceleration) of an underwater sound?

    I am looking for a way to estimate particle acceleration of an underwater sound produced by aquatic animals, per e.g. Something easy to use in the field and reliable. Like a vector sensor or an underwater geophone?

    Miłosz Grabowski

    Have you considered usage of the ADCP (acoustic doppler current profiler)?

  • Nicola Portunato added an answer:
    Is it possible to detect underwater sound by scanning the sea surface with a laser interferometer?

    I'm interested in understanding if is possible and feasible to detect and record underwater sound without touching the water, e.g. with a laser interferometer like those used to record sounds by detecting the vibrations of a surface like a glass window.

    Nicola Portunato

    forse ti può essere di aiuto !

  • Volker Deecke added an answer:
    Where is the fundamental frequency of this spectrogram?

    I'm new to acoustics and trying to describe and analyze loud calls of red langurs. Loud calls of this species has never been studied previously, so there's no reference I can look up to. I need suggestions to determine if: (please see attached image)

    1. the loud call is tonal or non-tonal (I think they're non-tonal)?
    2. is there any predefined "names" for the shape of the spectrogram (a, b1, b2)?
    3. where (on the spectrogram) is the fundamental frequency (F0)?

    Any inputs will be very appreciated. Thank you.

    Volker Deecke

    Just be careful to distinguish between 'biphonic' (one sound-producing structure generating multiple frequencies) and 'two-voiced' (two sound-producing structures producing two independent frequencies). Killer whales are likely an example of the latter (two nasal plugs operating independently). The following paper offers more detail: 

    Wilden, I., Herzel, H., Peters , G. & Tembrock, G. 1998. Subharmonics, biphonation and deterministic chaos in mammal vocalizations. Bioacoustics, 9, 171-196.

  • Mohammad mehdi Ommati added an answer:
    Can anyone recommend a video recording device that also has accurate acoustic recording?

    I am looking to record prairie dogs vocalizations paired with their behavior continuously in the field, so the device will be exposed to the elements.

    Mohammad mehdi Ommati

    Dear Elise,

    you can make a wooden open field equipped with a sound and video recorder. 

    The open field is a wooden box. your  box must be equipped with a webcam (2.0- Megapixel, Gigaware, UK) and a microphone and all activities were monitored from another room. for elimination of person effect.

    Good luck,


  • Filippo Maria Buzzetti added an answer:
    Do you know if there are studies on acoustic behaviour of Vespa velutina?

    I would like to study if Vespa velutina in their nests produce a particular sound.

    If yes, is this sound detectable from long dinstances? (up to 1 km)

    Do there are already studies like this?



    Filippo Maria Buzzetti

    Muchas gracias Juan Josè

  • Veronika Samotskaya added an answer:
    Does anybody have song recordings of African Reed Warblers (Acrocephalus baeticatus)?

    I am searching for good song recordings of African Reed Warblers. The longer the better. Or maybe somebody works near the habitat of these birds and it's not a big deal to record several minutes for me :)

    There are some recordings on, but they are way too short for the analysis :(

    Veronika Samotskaya

    Pavel, by the way, remember to write me criteria of the recording you use so I can record you something during the next season. Also, as soon as I know, I can ask my collegues, most likely they have a lot of Yellowhammer :)

  • Giuseppe Montesanto added an answer:
    What is the signification of the presence of a sound apparatus in a larval stage?

    It is a stridulatory apparatus which sound has never been heard in the larval stages. On the other hand the sound is audible on the adults. Does anyone has a biological idea or explanation of this phenomenon?

    Giuseppe Montesanto

    Dear Nahid, they're manca stages of terrestrial isopods.

  • Christophe Eggert added an answer:
    Do female midwife toads call back?

    I am currently trying to assess the population size of a non-native species here in England, the midwife toad (Alytes obstetricans). So far I have only found what I think are males (as they call) but I have noticed a difference in the kind of calls that are made by the toads.When I have looked at the calls using sonogram analysis software two different calls are distinguished. I was wondering if one could be from a male and the other from a female.

    I have attached a sonogram which shows a short section of one of my recordings. Am I right in thinking that individual A is a male and individual B is a female returning his call?

    Christophe Eggert

    In Alytes obstectricans Heinzmann describes six functionnally different calls in males and two types in females. The two were a mating call and a distress call.

    Heinzmann U. 1970. Untersuchungen zur Bio-Akustik un Okologie der Geburtshelferkröte, Alytes o. obstetricans (Laur.). Oecologia. 5. 19-55

  • Carlos B. Araújo added an answer:
    Are there "must have" books on bioacoustics which you can recommend?

    I wondered if there are any books that provide information you would have loved to have as a beginner?! That give a good basis (Background knowledge, Methods, dos and don'ts) so you can avoid unnecessary mistakes in data collection, analysis etc.

    Thank you!

    Carlos B. Araújo

    Soundscape Ecology: Principles, Patterns, Methods and Applications; of Almo Farina (2014) is certainly a must have for beginners.

  • Corrie Schoeman added an answer:
    Does the activity of non-echolocating bats can be affected by extreme human-induced noise?

    I am curious about the idea if it is possible that non-echolocating bat species may be affected by extreme noise. Since most of the studies published deals with echolocating species. Thanks in advance! 

    Corrie Schoeman

    Recently, we suggested that Eidolon dupreanum may use an incipient echolocation system (using laryngeal sound rather than wing clap sound as shown in the Boonman et al. 2014 paper) to navigate dark caves. So it seems likely that non-echolocation bats may be significantly affected by loud noise.

    Schoeman & Goodman 2012. Acta Chiropterologica 14: 409-416

  • Luis Henrique Soares Alves added an answer:
    I'm revising the Pseudopaludicola genus based on its bioacoustics. Could someone help me with recorded calls?
    Advertisement call of Pseudopaludicola species.
    Luis Henrique Soares Alves

    Boa tarde!

    Me passe seus questionamentos por email Descrevendo metodologia e objetivo para ver o que posso fazer.


  • Carlos B. Araújo added an answer:
    Can anyone study richess of song complexes of any species of Passeriformes NUMERICALLY?

    I study the riches of song complexes (dialects, sub-dialects etc) of Chaffinch (Fringilla coelebs) in Ukraine. But I did not found studies of numerical separation of these complexes and numerical description of their riches.

    Carlos B. Araújo

    You may use Shannon entropy measurements to calculate note disorder within the song. Please take o look in:

    SILVA, M. L. ; VIELLIARD, Jacques Marie Edme ; PIQUEIRA, J. R. C. 2000. Using shannon entropy on measuring the individual variability in the Rufous-bellied Thrush Turdus rufiventris vocal communication. Journal of Theoretical Biology, 207(1): 57-64, 

  • Eugenia Yablonovska-Grishchenko added an answer:
    Does anyone know this kind of great tit vocalization? May be a contact call?

    I’m recording great tit vocalizations around the nest during breeding. Males can use songs, alarm calls or this kind of call that I am not sure to identify (see the attached files).

    + 1 more attachment

    Eugenia Yablonovska-Grishchenko

    I identify the sound in file C5_F17_incub_out as some alarme call. This signal tits use to the address of man intruding into hteirs territory. I register this call in Kaniv Nature Reserve many times.

  • Eugenia Yablonovska-Grishchenko added an answer:
    What do you think about acoustical monitoring of owls with commercial recorders such as Olympus DM650?

    We (some Czech and Slovak ornithologists) use commercial recorders for owl monitoring (in a weatherproof box placed on the tree).

    I am looking for other people who use this method or similar. 

    Eugenia Yablonovska-Grishchenko

    I use Olympus LS11 for recordings of owls for individual discerning of Strix aluco. Its parameters are similar. Results are good: records at distanse 500-700 m are good-read at sonogram.

  • Gianni Pavan added an answer:
    Is it possible to estimate SPL (dB) of bird calls from .wav file (audio recording)?
    I am working on avian acoustic adaptations in urban habitats. I use Avisoft SAS LabPro and Raven Pro1.4 software. These software do give amplitude levels of sound but are exceptionally too high in comparison to measurement made by Sound Level Meter SVAN 957. What measurement setting should I do in the software for getting accurate SPL( dB) from the .wav files?
    Gianni Pavan

    if you use 1/4" omnidirectional microphones you can use a sound calibrator that fits on the microphone capsule. They usually produce 94dBSPL at 1kHz. Record the calibration tone at the beginning of each recording, or at least after any level adjustment. This way you always have a reference tone in your recordings to make measures of Received Level. Then you can assess Source Level if you have a good estimate of the distance form the source. The method is great if you have suitable microphones; it works perfectly with autonomous recorders designed to capture sounds at 360°, e.g. for soundscape recording.

    However the method can't apply if you use generic microphones, cardioids, supercardioids, or parabolas. In such a case you can use a speaker with a fixed tone; in open field (not in a room!) you can set your microphone and recorder, and use to a Sound Level Meter to measure the level you receive at the microphone and take a note of the level you're recording. Don't expect great accuracy as sound propagation is often complex and received levels may vary. Once you have a good measure for a given setup and recording level ..... don't make changes and do your recording .... If you can lock your configuration (microphone, cable, recording gain and recording level) you can go on for a while ..... but periodically it is recommended to verify the calibration.

  • Paul Crump added an answer:
    How do you calculate the number of true negatives using an automated acoustic classifier?

    I’m working on an automated frog call detection problem. I’m trying to determine a good way to estimate the number of true negatives within a given sample. The true and false positives, and the false negative are easy, but to perform some of the more sophisticated analyses, one needs a value for the true negatives. True negatives in this context can be defined as the sample space within which the automated classifier could have made an incorrect classification, but did not.

    My thought was to sum the time taken up by the true and false positives then add the time taken by the false negatives (determined by multiplying the number of false negatives by the mean time of a true positive). Then subtract that value from the overall time, leaving the time that was “at risk” of incorrect classification. Then divide the remaining time by the mean time of a false negative (with the logic that if it did make a hit, it would have been incorrect) to get the number of true negatives.

    The problem with this method is that it does not work when there are lots of calls, frequently the summed time exceeds the recording time, which makes sense. I am going to explore the use of the median, but I was curious if anyone else has gone down this particular path with any degree of success?



    Paul Crump

    Thank you Ronald and Benedikt for your suggestions.

  • Patrícia F Monticelli added an answer:
    Bioacoustics and saline environment, is there any study about?

    I am trying to understand signal evolution in terrestrial mammals in an environment such as neotropical beach (south of Brazil, municipality of Florianópolis,Santa Catarina), humid, saline, windy versus a rural more savana like environment. I know the classical studies of Richards and Willey, Aubin and Jouventin, but I could not find any study relating saline or humidity degrees with signal funtional structure. Any possible help? Any comparison made about bird species living in coastal versus savanna environment?    

    Patrícia F Monticelli

    Dear Hervé Glotin.

    Lets follow each other here in research gate! I am preparing papers yet, that shall discuss this. Did you mean researching together?

  • Olesya Anatolyevna Astakhova added an answer:
    In clades that duet, why does one species or subclade lose their duet?

    And more broadly, are there some good cases of bioacoustic signals being lost where the reason for the loss is well-studied?

    Olesya Anatolyevna Astakhova

    The crane (screaming birds) developed duets between female and male. In passerine birds developed song duets between males.

  • Alberto Behar added an answer:
    Decibelimeter model for bioacoustic research?

    I am looking for a decibelimeter for bioacoustic research that is not as expensive as a Brüel & Kjær and that has an enough quality. Any tips?

    Alberto Behar

    Larson Davis SLM are of comparable quality to B&K and the price is much lower.

    Strongly recommended!

  • Marie A Roch added an answer:
    Which is the best software for marine soundscape analysis?
    I am new to the soundscape analysis field. I am looking for a software that would allow me to analyse different metrics, from the basics (amplitude of a certain frequency band) to the advanced such as counting of specific signals (snapping shrimps snaps and fish vocalizations) and diversity indexes. I have limited experience with R and no experience at all with Matlab but I am willing to invest time in it if it is really worth it.
    Marie A Roch

    Dear Tullio,

    There is no magic bullet that will let you detect every type of signal.  For general data exploration, I'd suggest the following software packages:  xbat (Matlab program written by Harold Figueroa from Cornell - nicely done, no longer supported and documentation is supposed to be a bit on the slim side),. Cornell's Raven, Osprey (Matlab program written by Dave Mellinger at Oregon State that has some nice annotation features), or Triton (Matlab program written primarily by Sean Wiggins at Scripps Institution of Oceanography that is designed for very large datasets and has a nice compressed spectrogram function [some of the other packages have this as well]).  There are other packages out there as well.  For detecting calls, it really depends upon your soundscape and the calls you are interested in as to how easy that is to do.  The Teager energy detector was used by Kandia and Stylianou (2006) for detecting odontocete echolocation clicks and should work well for snapping shrimp; we developed it independently and while we never published as Kandia & Stylianou beat us to the punch our description can be seen in some our papers (look at Soldevilla et al. 2008 or Roch et al. 2011).  

    I haven't done work on fish calls, but I would expect that for pulsed calls you would want to key in on some aspect of the frequency range and pulse rate. 

    If you just want a general signal detector, you could look at the work of Erbe and King (2008), they designed a signal detector that is very easy to implement and can do a pretty nice job.

    Best of luck in your research - Marie

    Erbe, C., and King, A. R. (2008). "Automatic detection of marine mammals using information entropy," J. Acous. Soc. Am. 124(5), 2833-2840.

    Kandia, V., and Stylianou, Y. (2006). "Detection of sperm whale clicks based on the Teager-Kaiser energy operator," Appl. Acous. 67(11-12), 1144-1163.

    Roch, M. A., Klinck, H., Baumann-Pickering, S., Mellinger, D. K., Qui, S., Soldevilla, M. S., and Hildebrand, J. A. (2011). "Classification of echolocation clicks from odontocetes in the Southern California Bight," J. Acous. Soc. Am. 129(1), 467-475.

    Soldevilla, M. S., Henderson, E. E., Campbell, G. S., Wiggins, S. M., Hildebrand, J. A., and Roch, M. A. (2008). "Classification of Risso's and Pacific white-sided dolphins using spectral properties of echolocation clicks," J. Acous. Soc. Am. 124(1), 609-624.

  • Gianni Pavan added an answer:
    Which acoustic software do you use for simulations (underwater or outdoor propagation)?
    I usually deal with outdoor noise propagation (noise impact assessments). I use software like Cadna, Soundplan and Predictor. I'm Interested in bioacoustics (I don't do this for a job) I'd like to know if specific software (free and not) exists to study the noise effects on animals. Sometimes reading noise reports that deal with impacts on animals I noticed that usually a dB(A) is used. Is it correct that a human filter scale can study the noise effects on animals?
    Gianni Pavan

    Propagation plays an important role and in the marine environment it is really complex.

    The best available free software is ActUp, not easy but powerful:

  • Laura Kloepper added an answer:
    Is there any clue in song sonogram or spectrogram to understand which structure is producing the sound?
    I'm working with sound emission of Netrosoma (Orthoptera) from Mexico, together with Paolo Fontana. We are trying to understand which body parts are involved in sound emission since some spp are without stridulatory file.
    Laura Kloepper
    I agree with Charles Henry about anatomical validation. In our lab we have modified a GoPro action camera (which records at 240 frames per second and fantastic resolution) with macro lenses and have been getting incredible "high speed" video of echolocating bats for a fraction of typical high speed camera costs. Contact me directly if you'd like more information on this setup--all the components are available commercially from various companies.
  • Scott R. Veirs added an answer:
    What is the best sound production software to produce sounds from scratch?
    What is the best software to produce sounds from scratch with sequences/pulses of different frequencies and intensities, for a playback study?
    Scott R. Veirs
    I vote for (and use) opensource, free, platform-independent Audacity --

About Bioacoustics

Bioacoustics refers to the investigation of sound production, dispersion through elastic media, and reception in animals, including humans. This involves neurophysiological and anatomical basis of sound production and detection, and relation of acoustic signals to the medium they disperse through. The findings give us some evidence about the evolution of acoustic mechanisms, and from that, the evolution of animals that employ them.

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