Frequency range for microphone

[mishari]

@chris-aeviator do you have any information as to what the frequency we need for the microphones?

[chris-aeviator]

I think we're interested into something around 10-30hz, Veronika can answer the question precisely. Don't find the link to theGoogle doc with the meeting notes anymore, I remember writing something down there concerning the freq. ranges.

[mishari]

The document is here: https://docs.google.com/document/d/1DLlFmH0tx9jBkVGg6jCAMXO6qClVJ7AuWDVSdao-39g/edit?usp=sharing

[chris-aeviator]

Thanks! Here's the line

Existing microphone used by VK: Omni-directional Neumann KM183 condenser microphone (fitted with a windshield), modified for recording frequencies below 20 Hz (flat-recording down to 5 Hz)

[mishari]

Perhaps we actually don't need it down to 5Hz? Need to check with VK

[chris-aeviator]

I remember from our meeting that there was a distinct range where the elephant rumbles gave a strong signal over the noise and you are right, I think it was around the 30HZ range.

[VerBee]

Hello! Well as I said f you want to get the full range you need a microphone that goes to 10 Hz or beyond, if detection is possible with a microphone that only gets part of the range would be sth that needs to be tested because of course you loose some information of the typical spectral composition. I recently heard a talk from someone saying they had tried automatic detection with African elephants, I could contact them and ask if they could share their experience.

[VerBee]

It would also make sense to contact the people from Cornell University, they have worked with acoustic recorders and camera traps and developed AIs for automatic classification of African forest elephants, e.g. https://ojs.aaai.org/index.php/AAAI/article/view/3820