noise under harmonic vocalizations

[bmacagno]

Hi all,

I am looking at some recordings that contain a lot of harmonics. Interestingly, there is a lot of noise primarily under 30 kHz, although some of the noise bands are much much larger and encroach on the primary call component (around 60 kHz). They are almost exclusively under the harmonic vocalizations. I thought it might be noise due to the bedding I have in a cage, but I am recording mouse pups at pnd 6 and 8 where I wouldn't expect them to move around very much. Some of the harmonic vocalizations within the same recording are very clear with no noise. Does anyone know what this noise may be attributed to ? Or how I should go about finding the source on my own? Any insight would be very appreciated

Thanks!

Bea Macagno
Department of Psychology
Western Washington University

[bmacagno]

Here are examples of narrow, wide and no noise bands