Vocalizations
There are two different types of songs. The A-song is a short, purring trill, followed by two accentuated clear notes, described by Lane (in Schulenberg et al. 2007) as "a slow, rolling trill usually ending with a longer, punctuated note (occasionally doubled): ' pu-pu-pu-pu-pu-pu-POO.' " When the owls are excited (e.g. after playback), the last notes may be uttered in a ‘stuttering’ rhythm and may be more numerous. The female produces a similar song to the normal A-song from the male, but it is sung less frequently and is slightly higher pitched (König and Weick 2008). Both sexes give the B-song (König and Weick 2008). The B-song is a bubbling bububúbubu, and and is often heard during courtship or when they begin singing at dusk.
Other vocalizations include "a variety of cackles and longer hooting notes, particularly when agitated" (Lane, in Schulenberg et al. 2007)