Rufous-necked Wood-Rail is most vocal at dawn and dusk (ffrench 1991, Howell and Webb 1995), and also calls at night (Taylor 1998). Individuals often duet antiphonally (Whitney in Ridgely and Gwynne 1989, ffrench 1991, Howell and Webb 1995). The song variously is described as "consisting of loud, irregularly paced kip and kow notes, e.g., kip-kow-kip, kow-kip-kow, kip-kowkip-kow, kow, kow, kow-kip ... " (Whitney, in Ridgely and Gywnne 1989); as "an incisive, loud series, pik- pik-pik or pyok-pyok-pyok repeated about 8 times" (ffrench 1991); as "a loud and incisive series of kyow notes repeated steadily for 5-10 seconds or sometimes even longer, occasionally varied to a more irregular kip-kyow-kip ...." (Ridgely and Greenfield 2001b); and as a duet composed of "a strident series of musical notes, the notes of the pair overlapping haphazardly: CHI burr... CHI burr... CHI burr...." (Lane, in Schulenberg et al. 2010).
Additional vocalizations of Rufous-necked Wood-Rail are described as "a cluck and kik in alarm" (ffrench 1991). Kessler (in Parker et al. 1995) also reported a clicking sound from an adult with downy chicks, and a series of grunts and squeaks from a second adult that confronted Kessler while the other adult led the chicks away.