I started exploring how monkeys process sounds during my postdoctoral fellowship with Tony Wright at the U-Texas Health Science Center & Anderson Medical Center in Houston, TX. I started by modernizing the lab's sound presentations to digital form so that we could randomize the presentation of sounds and build a large bank of sound effects, natural sounds, melodies, chords, and pure pitch examples to select from daily to present to rhesus monkeys.
The result was the first study linked below (2000), which demonstrated that rhesus monkeys can generalize melodies that were built by humans (like Happy Birthday song) readily by 1 - 2 octaves. This suggests that their memory of the melody was more a whole unit, a gestalt, of the shape of the sounds in order. This article has been cited more and by a wider audience than almost anything else I've worked on to date. The idea of a melodic structure that is learned and recognized in different octaves by rhesus monkeys crosses species lines and attributes similar processing to both.
The second article linked below (2013) relates to early attempts to study sounds in sequences via artificial grammatical structures, and it was in response to a tribute to Tony Wright that I wrote it. The video clip in "About" is an example of this study, but see the link to Artificial Grammar Learning to read more about the complete study of this by 2017.
Read the article published on how rhesus monkeys generalize melodies (2000).
CITATION: Wright, A. A., Rivera, J. J., Hulse, S. H., Shyan, M., & Neiworth, J. J. (2000). Music perception and octave generalization in rhesus monkeys. Journal of experimental psychology. General, 129(3), 291–307. https://doi.org/10.1037//0096-34184.108.40.2061
Read the article published on how tamarins discriminate sounds, including phonemes, tones, and monkey calls (2013).
CITATION: Neiworth J. J. (2013). Chasing sounds. Behavioural processes, 93, 111–115. https://doi.org/10.1016/j.beproc.2012.11.009