<p>First, I would relax the requirements and not insist on &quot;precise measurements&quot;,  &quot;highly accurate measurements&quot; and &quot;accurate differentiate&quot;. Computer program may give you this type of quality, but if you do not have the same requirement on the measurements, then you be always off. That is why laboratory measurements with very controlled settings have been and are made.</p>
<p>To answer your last question on on-/off-axis clicks, one can easily say, that</p>
<ul>
<li>all echolocation clicks that are measured to have about the same received level, can be considered off-axis clicks as echolocating (whales and dolphins) are scanning the environment.</li>
<li>The strongest click in an echolocation scan is as close as you can get to an on-axis click. If you have a sequence of close to on-axis clicks, then the one which is shortest click is the one closest to on-axis, as off-axis distortion lengthen the click.</li>
<li>To really know, if a click is truly on-axis you need to know that the echolocation beam of the animal is pointing towards the hydrophone.</li>
</ul>

CC BY-SA 4.0
2022-07-10T16:01:34.250Z
2022-07-11T08:10:26.923Z
2022-07-11T08:10:26.923Z
WMXZ
<p>The R package <a href="https://taikisan21.github.io/PAMpal/" rel="nofollow noreferrer">PAMpal</a> will calculate a suite of parameters (including the ones you mentioned) and it is designed to work with PAMGuard click and whistle detectors. It is available on Cran and also through Taiki Sakai's github account (the PAMpal link above).</p>

CC BY-SA 4.0
2022-07-11T20:18:54.623Z
2023-04-19T11:56:38.893Z
2023-04-19T11:56:38.893Z
ASimonis
<p>The issue of how to select on-axis clicks has been addressed in several of these papers:</p>
<p><a href="https://marinebioacoustics.files.wordpress.com/2021/03/malinka_etal_2021_jeb_kogia.pdf" rel="nofollow noreferrer">https://marinebioacoustics.files.wordpress.com/2021/03/malinka_etal_2021_jeb_kogia.pdf</a></p>
<p>Ladegaard M., Mulsow J., Houser D.S., Jensen F.H., Johnson M., Madsen P.T., Finneran J.J. (2019),”Dolphin echolocation behaviour during active long-range target approaches”, J. Exp. Biol., 222 (2), jeb189217, doi: 10.1242/jeb.189217</p>
<p><a href="https://marinebioacoustics.files.wordpress.com/2018/05/de_freitas_etal_2018.pdf" rel="nofollow noreferrer">https://marinebioacoustics.files.wordpress.com/2018/05/de_freitas_etal_2018.pdf</a></p>
<p>We compute those spectral metrics in matlab and can provide code if useful?</p>

CC BY-SA 4.0
2022-07-11T08:15:16.300Z
Hi @Marinebioacoustics Aarhus Univ, could you please provide a little bit of detail on the click selection in the answer itself. Answers with only links to other questions are discouraged on SE ([SE discussion link](https://meta.stackexchange.com/questions/156941/one-line-answers)).
Thejasvi
CC BY-SA 4.0
2022-07-11T14:50:46.583Z
The malinka et al paper uses a vertical array where the mentioned criteria are valid.
WMXZ
CC BY-SA 4.0
2022-07-11T07:57:38.183Z
2022-07-11T07:57:38.183Z
Marinebioacoustics Aarhus Univ
<p>We have Matlab software available for extracting signal parameters from biosonar clicks - you should be able to download software here: <a href="https://github.com/frantsjensen/Biosonar_array_toolbox" rel="noreferrer">https://github.com/frantsjensen/Biosonar_array_toolbox</a></p>
<p>These tools were made mainly for linear recording arrays and include GUIs for selecting presumed on-axis clicks from array recordings, for localizing the source of clicks, and estimating both received and source parameters. They have been used by a variety of students in our lab in the past but arguably need more documentation to be more widely accessible.</p>
<p>Identifying on-axis clicks is not easy. Star-shaped (2D) arrays are in some ways better for this since you can isolate clicks that have the highest received level on the center hydrophone compared to hydrophones on the periphery. However, such arrays typically have relatively small aperture and thus limited localization range.</p>
<p>We have tended to use linear arrays because of their longer localization range.  With a linear array, you can estimate the off-axis angle in the plane of the array (typically the vertical plane) but not in the plane orthogonal to your array. To overcome this, we focus on click series where animals are approaching the array (preferably verified visually) and scanning their sonar across the array, then for each scan we pick the click with the highest back-calculated source level.</p>

CC BY-SA 4.0
2022-07-11T13:40:10.267Z
2022-07-11T13:40:10.267Z
Frants Jensen
<p>I am looking for some advice regarding software/code that is appropriate for obtaining precise measurements of echolocation click parameters (peak frequency, 3 and 10 dB bandwidth, etc.). While I know there are some methods available for reporting measurements from a dataset of clicks, I am hoping to find something that allows for highly accurate measurements of a small subset of representative clicks.</p>
<p>Additionally, I'm interested in learning what software/code people use to accurately differentiate on and off axis clicks from a subset of representative clicks.</p>
<p>Appreciate the thoughts/input!</p>

<measurement><echolocation-clicks>
Echolocation Click Measurement
# Echolocation Click Measurement

(Asked by: username_0 on 2022-07-10)

I am looking for some advice regarding software/code that is appropriate for obtaining precise measurements of echolocation click parameters (peak frequency, 3 and 10 dB bandwidth, etc.). While I know there are some methods available for reporting measurements from a dataset of clicks, I am hoping to find something that allows for highly accurate measurements of a small subset of representative clicks.

Additionally, I'm interested in learning what software/code people use to accurately differentiate on and off axis clicks from a subset of representative clicks.

Appreciate the thoughts/input!

**Tags:** measurement, echolocation-clicks


---

## 4 answers

### Answer by username_5 on 2022-07-11. Score: 11 | Accepted answer

We have Matlab software available for extracting signal parameters from biosonar clicks - you should be able to download software here: <https://github.com/username_5/Biosonar_array_toolbox>

These tools were made mainly for linear recording arrays and include GUIs for selecting presumed on-axis clicks from array recordings, for localizing the source of clicks, and estimating both received and source parameters. They have been used by a variety of students in our lab in the past but arguably need more documentation to be more widely accessible.

Identifying on-axis clicks is not easy. Star-shaped (2D) arrays are in some ways better for this since you can isolate clicks that have the highest received level on the center hydrophone compared to hydrophones on the periphery. However, such arrays typically have relatively small aperture and thus limited localization range.

We have tended to use linear arrays because of their longer localization range. With a linear array, you can estimate the off-axis angle in the plane of the array (typically the vertical plane) but not in the plane orthogonal to your array. To overcome this, we focus on click series where animals are approaching the array (preferably verified visually) and scanning their sonar across the array, then for each scan we pick the click with the highest back-calculated source level.


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### Answer by username_1 on 2022-07-10. Score: 8

First, I would relax the requirements and not insist on "precise measurements", "highly accurate measurements" and "accurate differentiate". Computer program may give you this type of quality, but if you do not have the same requirement on the measurements, then you be always off. That is why laboratory measurements with very controlled settings have been and are made.

To answer your last question on on-/off-axis clicks, one can easily say, that

* all echolocation clicks that are measured to have about the same received level, can be considered off-axis clicks as echolocating (whales and dolphins) are scanning the environment.
* The strongest click in an echolocation scan is as close as you can get to an on-axis click. If you have a sequence of close to on-axis clicks, then the one which is shortest click is the one closest to on-axis, as off-axis distortion lengthen the click.
* To really know, if a click is truly on-axis you need to know that the echolocation beam of the animal is pointing towards the hydrophone.


---

### Answer by username_2 on 2022-07-11. Score: 7

The R package [PAMpal](https://taikisan21.github.io/PAMpal/) will calculate a suite of parameters (including the ones you mentioned) and it is designed to work with PAMGuard click and whistle detectors. It is available on Cran and also through Taiki Sakai's github account (the PAMpal link above).


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### Answer by username_3 on 2022-07-11. Score: 2

The issue of how to select on-axis clicks has been addressed in several of these papers:

<https://username_3.files.wordpress.com/2021/03/malinka_etal_2021_jeb_kogia.pdf>

Ladegaard M., Mulsow J., Houser D.S., username_5 F.H., Johnson M., Madsen P.T., Finneran J.J. (2019),”Dolphin echolocation behaviour during active long-range target approaches”, J. Exp. Biol., 222 (2), jeb189217, doi: 10.1242/jeb.189217

<https://username_3.files.wordpress.com/2018/05/de_freitas_etal_2018.pdf>

We compute those spectral metrics in matlab and can provide code if useful?

> **Comments:**
> **username_4**: Hi @username_3, could you please provide a little bit of detail on the click selection in the answer itself. Answers with only links to other questions are discouraged on SE ([SE discussion link](https://meta.stackexchange.com/questions/156941/one-line-answers)).  
> **username_1**: The malinka et al paper uses a vertical array where the mentioned criteria are valid.  

---

