Figure 2. Oscillogram, spectrogram and magnitude spectrum of a Type 2 vocalization emitted by a male Glaucomys volans in proximity to a female conspecific.

Shown is one of four calls emitted in the sequence. Both animals were house separately in a room lined with sound attenuating foam at McMaster University. Note the prominent frequency (FM) and amplitude modulations (AM) in the signal, and the clear presence of harmonics. Call duration  = 135 ms.