How to test the microphone?

By dirt or moisture, the sensitivity of the BATLOGGER microphone may be impaired. With a simple method one can test the functionality of the microphone:

Mic Test 01
Mic Test 02

  • Go to a maximal quiet environment
  • Place the protective cap onto the microphone or gently press a sound-absorbing object (eg earplugs) onto the microphone
  • Make a manual recording (press >>)
  • Select approx. one second silence of the recording (wav file) and display the spectrum (eg. with Audacity -> Analyse -> frequency analysis)

Microphone OK

  • Noise level of approx. -49dB @ 65 kHz
  • Flat spectrum +/- 3dB @ 15 - 90 kHz

Mic Test 03

Microphone bad:

  • Low sensitivity (<-50 dB) @ 20 - 50 kHz
  • High noise (>-40 dB) over entire bandwidth
  • Lots of peaks over the whole spectrum

Mic Test 04
Mic Test 05

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