(0.8s, 7 kb mp3) an isolated hiss.
The hiss consists of 3 distinct lobes, separate by brief silences.
The sonogram and closeups below shows a complex mix of frequencies.
The sonogram on the left shows dominant audio frequencies at 6000 hz,
corresponding (x16) to ultrasounds near 100 khz!
A closeup look at the center lobe.
Picture 3 -- Time axis in audio samples, 32000 samples = 1 sec
A very closeup look at a region of the center lobe where
14 periods are identifiable over 70 samples.
The sampling rate is 32000 per second, so the audio frequency is
14*32000/70 = 6400 hz.
The bat is emitting ultrasounds at (x16) 102.4 Khz!