27
votes
Accepted
If I don't know the source level of an animal's vocalization, is there still a meaningful way to measure how loud the signal is?
If your hydrophone system is calibrated, then it sounds like you do have the information you need to estimate a source level using a simple sonar equation: RL = SL-TL (Received level = Source Level - ...
- 2,091
5
votes
Can I convert dB(A) into dB?
The dB(A) levels are derived from the power spectrum, so if you can calculate the power spectrum then you do not need to back-calculate, you already have the power spectrum.
If, however, you have not ...
- 7,620
4
votes
Accepted
Is dB SPL always RMS?
Yes, more often than not you can safely assume that all level quantities are calculated based on RMS values unless stated otherwise.
It doesn’t make much sense to provide level measurements of ...
- 314
4
votes
Is dB SPL always RMS?
Yes, you can assume dB SPL is based on RMS.
As far as I understand, Sound Pressure Level (SPL) is always based on root-mean-square (RMS) measurements. This is obvious for signals that last longer than ...
- 7,620
3
votes
Accepted
Is it common to have a negative-positive dB range in underwater spectrograms?
There are two types of answers, technically or physically.
technically, there is nothing wrong with positive and negative dB values, all depends on dBref; you can use any dBref you find interesting ...
- 7,620
3
votes
What are linear decibels (dBL) and how do they compare to standard dB SPL?
dB(L) or dB linear is a term we use in the explosives industry for measuring air overpressure. It is the same as dB SPL and the term linear is just meant to clarify that the unit does not have a ...
- 31
3
votes
What are linear decibels (dBL) and how do they compare to standard dB SPL?
A decibel (dB) is a logarithmic scale as you correctly understand. Why someone adds a 'linear' attributes to it, is confusing. I never have come across such term.
IMHO, Without seeing the EIS, there ...
- 7,620
2
votes
Accepted
Standardising spectrogram amplitude
The problem lies in your reference "ref=np.max", which tells the amplitude_to_db() to scale all data to the maximum power level.
As you wanted to compare the different datasets you must use ...
- 7,620
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