<p>I will defer to @DanStowell's reply/comment on whether 1 minute is an OK duration.</p>
<p>Regarding analyzing the last minute, which may be &lt;1 min, I would just <em>exclude</em> this from the data analysis since:</p>
<ul>
<li>you have &quot;hundreds or thousands of hours of acoustic recordings&quot; (so what's it to lose 45 seconds), and</li>
<li>I don't think it's fair to compare this metric when it's been calculated on windows of varying lengths.</li>
</ul>

CC BY-SA 4.0
2023-01-31T02:13:35.833Z
I would agree with @chloe that excluding the incomplete minutes makes sense.  Some of the indices are counts of different types of events so if the denominator varies (we are assuming that each row is 1 minute long) then you lose the meaning of the counts. That is unless you know how long the last "minute" actually was and then you might be able to correct for it. This is all assuming the last recording/minute is at least, say, 30 seconds.
Abram Fleishman
CC BY-SA 4.0
2023-01-30T13:06:25.470Z
2023-02-15T19:21:19.440Z
2023-02-15T19:21:19.440Z
Chloe
<p>I'm calculating soundscape indices using scikit-maad's <a href="https://scikit-maad.github.io/generated/maad.features.all_temporal_alpha_indices.html#maad.features.all_temporal_alpha_indices" rel="noreferrer"><code>all_temporal_alpha_indices</code></a> and <a href="https://scikit-maad.github.io/generated/maad.features.all_spectral_alpha_indices.html#maad.features.all_spectral_alpha_indices" rel="noreferrer"><code>all_spectral_alpha_indices</code></a>.  I will be using them as a &quot;screen&quot; to help identify areas of interest in hundreds or thousands of hours of acoustic recording.  So was thinking to partition the recording into 1-minute windows and calculate the indices to 1 minute at a time.</p>
<p>Is there a minimum duration that the functions will work well for?  Is 1 minute too short?</p>
<p>Or even if 1 minute is fine, the last window of a file might be incomplete, i.e. not a full minute.  In that case I was thinking to still calculate the indices on the shorter window, unless there's some min duration under which the indices are not meaningful.</p>

CC BY-SA 4.0
2023-01-27T08:36:31.293Z
I would expect 1 minute to be OK, largely because other people use that as a resolution for acoustic indices. Smaller than 1 minute doesn't allow time for very much acoustic variation, or for many acoustic events for MAAD's detections. But I haven't used MAAD myself, hence a comment rather than an answer.
Dan Stowell
<soundscape><python><acoustic-indices>
Is there a minimum duration that maad indices will work on?
# Is there a minimum duration that maad indices will work on?

(Asked by: username_0 on 2023-01-25)

I'm calculating soundscape indices using scikit-maad's [`all_temporal_alpha_indices`](https://scikit-maad.github.io/generated/maad.features.all_temporal_alpha_indices.html#maad.features.all_temporal_alpha_indices) and [`all_spectral_alpha_indices`](https://scikit-maad.github.io/generated/maad.features.all_spectral_alpha_indices.html#maad.features.all_spectral_alpha_indices). I will be using them as a "screen" to help identify areas of interest in hundreds or thousands of hours of acoustic recording. So was thinking to partition the recording into 1-minute windows and calculate the indices to 1 minute at a time.

Is there a minimum duration that the functions will work well for? Is 1 minute too short?

Or even if 1 minute is fine, the last window of a file might be incomplete, i.e. not a full minute. In that case I was thinking to still calculate the indices on the shorter window, unless there's some min duration under which the indices are not meaningful.

**Tags:** soundscape, python, acoustic-indices

> **Comments:**
> **username_1**: I would expect 1 minute to be OK, largely because other people use that as a resolution for acoustic indices. Smaller than 1 minute doesn't allow time for very much acoustic variation, or for many acoustic events for MAAD's detections. But I haven't used MAAD myself, hence a comment rather than an answer.  

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## 1 answers

### Answer by username_2 on 2023-01-30. Score: 2 | Accepted answer

I will defer to @username_1's reply/comment on whether 1 minute is an OK duration.

Regarding analyzing the last minute, which may be <1 min, I would just *exclude* this from the data analysis since:

* you have "hundreds or thousands of hours of acoustic recordings" (so what's it to lose 45 seconds), and
* I don't think it's fair to compare this metric when it's been calculated on windows of varying lengths.

> **Comments:**
> **username_3**: I would agree with @username_2 that excluding the incomplete minutes makes sense.  Some of the indices are counts of different types of events so if the denominator varies (we are assuming that each row is 1 minute long) then you lose the meaning of the counts. That is unless you know how long the last "minute" actually was and then you might be able to correct for it. This is all assuming the last recording/minute is at least, say, 30 seconds.  

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