The song of Olive Finch is a "pleasant yet fast series of high pitched sibilant whistles" lasting more than ten seconds (Rising et al. 2010) that has been transcribed as tsee-tsi-tsi-tsi-titti-tsi-tsi-tsi-tsi-tsu-tsii (Ridgely and Greenfield 2001b). All the notes in the long song are high in frequency, with the song slightly cascading up and down in pitch (Jaramillo 2011).
For a representative audio recording with sonogram, see audio
The song of Olive Finch is similar to at least two other species in its breeding range. The song of Chestnut-capped Brushfinch (Arremon brunneinucha) is similar but is shorter and typically less continuous (Schulenberg et al. 2010). The song of Ecuadorian Piedtail (Phlogophilus hemileucurus) also is similar but is "more shrill and lisping in quality" (Schulenberg et al. 2010).