If I remember correctly, the frequency is ultrasonic. I'm not having much luck with Google.
Guessing that a ultrasonic microphone from a bioaccoustics site should fit the bill - otherwise, what could researchers pick themselves?
This one, for example, picks up to 200kHz for €1050:
https://avisoft.com/ultrasound-microphones/cm24-cmpa/
alt Hacker News
Guessing that a ultrasonic microphone from a bioaccoustics site should fit the bill - otherwise, what could researchers pick themselves?
This one, for example, picks up to 200kHz for €1050:
https://avisoft.com/ultrasound-microphones/cm24-cmpa/