Picture 1

0712-4 sound (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!


Picture 2

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!