<p>This is tricky because a method of estimation that works for one environment, might not be as accurate in another. In <a href="https://www.frontiersin.org/articles/10.3389/fmars.2021.669528/full" rel="noreferrer">Haver 2021</a> we adopted the 1/3 octave bands (63 and 125 Hz) method from the European Marine Strategy Framework Directive and found that method to be an acceptable proxy for cargo and tanker activity at a handful of deep (&gt;500 m) sites in U.S. waters. More detailed detectors may be more precise but at high cost of analyst time and computing resources.</p>
<p>It also depends on the question. In our 2019 paper, we were specifically targeting noise in the primary communication frequencies for humpback whales, but those frequencies might not be as relevant for a different species.</p>

CC BY-SA 4.0
2022-07-06T19:36:41.590Z
2022-07-06T19:36:41.590Z
Samara H
<p>On top of other specialized metrics to cover for example whale call bands, I suggest that third octave (or decidecades as we should now call them) level should always be reported as most other broad band metrics can be deduced from those by readers in the future.</p>

CC BY-SA 4.0
2022-07-07T06:52:27.303Z
2022-07-07T06:52:27.303Z
Marinebioacoustics Aarhus Univ
<p>We attempted to provide meaningful feedback to this question with the <a href="https://northsearegion.eu/jomopans/" rel="nofollow noreferrer">JOMOPANS</a> project, were we employ the sound pressure level (SPL) of third-octave level (TOL) bands from different stations around the North Sea to build our modeled noise maps.  <a href="https://northsearegion.eu/media/17742/jomopans_wp3-standard-data-processing_final.pdf" rel="nofollow noreferrer">Ward et al., 2021</a> put out an EU report detailing what standards we used when processing our data.</p>
<p>However, in the GES Tool that we created for the project (<a href="https://jomopansgestool.au.dk/en/" rel="nofollow noreferrer">https://jomopansgestool.au.dk/en/</a>), we limited our users to view both the 63 and 125 Hz TOL bands, as they are important for historical and practical reasons, and then we provided decade bands of a broader scope.</p>
<p>How do you choose? I think it depends on your question.  What types of vessels are you interested in investigating? What impact are you trying to measure? Looking at the 125 Hz TOL will allow you to have a broader comparison with older publications, but as you mentioned, increasingly studies want to include higher frequencies as not all boats are built the same. As <a href="https://www.nature.com/articles/s41598-019-51222-9" rel="nofollow noreferrer">Hermannsen et al., 2019</a> pointed out, smaller, recreational vessels impact the higher frequencies.</p>
<p><a href="https://i.sstatic.net/0v6Tz.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/0v6Tz.png" alt="enter image description here" /></a></p>
<p><strong>References</strong></p>
<p>Hermannsen, L., Mikkelsen, L., Tougaard, J., Beedholm, K., Johnson, M., &amp; Madsen, P. T. (2019). Recreational vessels without Automatic Identification System (AIS) dominate anthropogenic noise contributions to a shallow water soundscape. Scientific reports, 9(1), 1-10.</p>
<p>Ward, J., Wang, L., Robinson, S., &amp; Harris, P. (2021). Standard for Data Processing of Measured Data. Report of the EU INTERREG Joint Monitoring Programme for Ambient Noise North Sea (Jomopans).</p>

CC BY-SA 4.0
2022-07-07T08:08:38.397Z
2022-07-07T08:08:38.397Z
etgriffiths
<p>Some studies, like <a href="https://www.frontiersin.org/articles/10.3389/fmars.2019.00500/full" rel="noreferrer">Haver et al 2019</a> use broadband measurements between 50 Hz - 1.5 kHz, but <a href="https://asa.scitation.org/doi/full/10.1121/10.0001726" rel="noreferrer">Haver et al 2020</a> looked for shipping noise in median power spectral densities between 10 Hz - 2 kHz, and <a href="https://www.sciencedirect.com/science/article/pii/S0025326X20307669" rel="noreferrer">Bittencourt et al 2020</a> used a variety of third-octave-levels. How do you choose which soundscape metric is best to monitor shipping noise?</p>

<soundscape><noise>
What soundscape metrics best capture shipping noise?
# What soundscape metrics best capture shipping noise?

(Asked by: username_0 on 2022-07-06)

Some studies, like [Haver et al 2019](https://www.frontiersin.org/articles/10.3389/fmars.2019.00500/full) use broadband measurements between 50 Hz - 1.5 kHz, but [Haver et al 2020](https://asa.scitation.org/doi/full/10.1121/10.0001726) looked for shipping noise in median power spectral densities between 10 Hz - 2 kHz, and [Bittencourt et al 2020](https://www.sciencedirect.com/science/article/pii/S0025326X20307669) used a variety of third-octave-levels. How do you choose which soundscape metric is best to monitor shipping noise?

**Tags:** soundscape, noise


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## 3 answers

### Answer by username_3 on 2022-07-07. Score: 4 | Accepted answer

We attempted to provide meaningful feedback to this question with the [JOMOPANS](https://northsearegion.eu/jomopans/) project, were we employ the sound pressure level (SPL) of third-octave level (TOL) bands from different stations around the North Sea to build our modeled noise maps. [Ward et al., 2021](https://northsearegion.eu/media/17742/jomopans_wp3-standard-data-processing_final.pdf) put out an EU report detailing what standards we used when processing our data.

However, in the GES Tool that we created for the project (<https://jomopansgestool.au.dk/en/>), we limited our users to view both the 63 and 125 Hz TOL bands, as they are important for historical and practical reasons, and then we provided decade bands of a broader scope.

How do you choose? I think it depends on your question. What types of vessels are you interested in investigating? What impact are you trying to measure? Looking at the 125 Hz TOL will allow you to have a broader comparison with older publications, but as you mentioned, increasingly studies want to include higher frequencies as not all boats are built the same. As [Hermannsen et al., 2019](https://www.nature.com/articles/s41598-019-51222-9) pointed out, smaller, recreational vessels impact the higher frequencies.

[![enter image description here](https://i.sstatic.net/0v6Tz.png)](https://i.sstatic.net/0v6Tz.png)

**References**

Hermannsen, L., Mikkelsen, L., Tougaard, J., Beedholm, K., Johnson, M., & Madsen, P. T. (2019). Recreational vessels without Automatic Identification System (AIS) dominate anthropogenic noise contributions to a shallow water soundscape. Scientific reports, 9(1), 1-10.

Ward, J., Wang, L., Robinson, S., & Harris, P. (2021). Standard for Data Processing of Measured Data. Report of the EU INTERREG Joint Monitoring Programme for Ambient Noise North Sea (Jomopans).


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### Answer by username_1 on 2022-07-06. Score: 5

This is tricky because a method of estimation that works for one environment, might not be as accurate in another. In [Haver 2021](https://www.frontiersin.org/articles/10.3389/fmars.2021.669528/full) we adopted the 1/3 octave bands (63 and 125 Hz) method from the European Marine Strategy Framework Directive and found that method to be an acceptable proxy for cargo and tanker activity at a handful of deep (>500 m) sites in U.S. waters. More detailed detectors may be more precise but at high cost of analyst time and computing resources.

It also depends on the question. In our 2019 paper, we were specifically targeting noise in the primary communication frequencies for humpback whales, but those frequencies might not be as relevant for a different species.


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### Answer by username_2 on 2022-07-07. Score: 2

On top of other specialized metrics to cover for example whale call bands, I suggest that third octave (or decidecades as we should now call them) level should always be reported as most other broad band metrics can be deduced from those by readers in the future.


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