Microphone and ePTFE

In the Welcome Session Akiba mentioned using ePTFE for waterproofing mics. Is this membrane suitable for application with mics that are used for detecting ultrasound signals, e.g., bat echolocation calls? I looked at some documentation and the responsiveness appears to be significantky reduced at higher frequencies. Does anyone have any experience with this material or suggestion for other materials?

Hi Cryssy,

    I am also looking for membranes to waterproof mics used for recording bat ultrasound. The people at Open Acoustics Devices is using  Porelle® AV5ID acoustic membranes for the AudioMoth moulded case (https://github.com/OpenAcousticDevices/Application-Notes/blob/master/An_Injection_Moulded_Case_for_AudioMoth.pdf). I wonder if someone in the WildLabs Community may know how to get them in small quantities. I have only found dealers that sell them in large quantities (+2000), I guess for the cell phone market (for example, https://selectronix.co.uk/collections/waterproof-acoustic-vents/products/black-acoustic-vent-11x5mm-ip68-3m-30min).

    Let me know if you find something,

    Best wishes,  Toni