Audio Quality
Example Recordings
How does AudioMoth compare?
AudioMoth's audio quality is fit for purpose for many environmental and biodiversity applications. The following links are evaluations and comparisons from AudioMoth users.
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AudioMoth for birds (nocmig) - by Simon Gillings and Nick Moran
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AudioMoth for bats - by David Brown
A nice way to visualise audio quality is looking at the difference between a recorded known signal and recorded noise present at silence, known as signal to noise ratio (SNR). Below are four plots used to calculate the SNR of AudioMoth and a widely used wildlife monitoring device, the SongMeter SM2. The top plots are 1kHz sine wave signals recorded at close to full range and the bottom plots are silence recordings showing low level noise. AudioMoth's SNR is 44.2dB, ~4.5dB less than the SM2. If you would like to discuss your applications audio quality requirements further, please get in touch on the support forum.
AudioMoth
Mic: On-board MEMS, 48kHz sample rate, max gain
SongMeter SM2
Mic: SMXII, 48kHz sample rate, min (default) gain
1kHz @ 1 m, ~1 Pa
Silence
SNR: 44.2 dB
1kHz @ 1 m, ~1 Pa
Silence
SNR: 48.7 dB
Measurement Procedure
For this test we played a 1kHz sound source @ ~1 Pa measured from 1 m. Devices were positioned 1 m away from the sound source and gain was adjusted to achieve close to full range. Measurements were repeated with the same settings in silence and SNR was then calculated from the two measurements.