The song of Bicolored Antpitta is a high, clear, whistled treeeee or treeeeeuh. Apparently, the female sometimes follows this with a kree-kree-kree-kree-kree-kree (Nilsson et al. 2001, Nilsson in Ridgely and Tudor 2009). The typical song lasts only around a second, and is delivered at intervals of 3-4 sec., at a frequency of around 2 kHz (Krabbe and Schulenberg 2003). The end of the song is usually upslurred and then downslurred (or the reverse).
For a representative audio recording with sonogram, see audio
The presumed "reply" of the female is described by Krabbe and Schulenberg (2003) as a 5-6 second-long delivery of 6-7 whistles, descending from around 2.5 kHz to 2 kHz.