Vocalizations between between female and male gibbons are essential to maintaining communication in their dense, forested habitats.  The vocal repertoire of the white-handed gibbon (Hylobates lar) consists of twenty-eight acoustic units, including the /s/, /t/, and /u/ units. These units occur as /s/, /s-t/ bigram, or /s-t-u/ trigram within the vocal repertoire. Reanalysis of the data suggests that the /s/ acoustic units should be divided into additional subcategories. Adobe Audition CC 2017.0.2 was used to measure the start, stop, fundamental, maximum, minimum, and dominant frequencies for each acoustic unit type, as well as the bandwidth and duration of the calls. These classification features were used to subdivide the /s/ unit using a Principal Component Analysis (PCA) and Discriminant Function Analysis (DFA); however further subdivisions of the /t/, and /u/ units were not supported. If new categorizations of the acoustic units are found to be perceptually recognized by gibbons, this could influence future studies on gibbon comprehension and vocalization usage.