The song of Such’s Antthrush is a long series of 20-40 hollow notes, loudest near the middle and quieter at the beginning and end, similar to the song of Short-tailed Antthrush (C. campanisona), but longer and lacking the terminal "grunts". The sonogram presented by Willis (1992) was of a song 22.8 s long, which included 165 notes, and rose from 1,250 to 1,600 Hz at regular 2.1 Hz per note.
For a representative audio recording with sonogram, see audio
One described call is an abrupt quick! note (Krabbe and Schulenberg 2003).