A key function of the male's large nose is its acoustic impact, transforming the male into a natural sound resonator. When the monkey vocalizes, especially during displays of excitement, alarm, or social challenge, the cavity of the enlarged nose acts as an amplification chamber, producing loud and deep resonant calls. These low-frequency "honks" and "roars" travel further through the dense forest environment, effectively communicating the male's presence and vigor across long distances. This acoustic advantage allows the dominant male to assert his territory and warn off competitors without always needing a physical confrontation.
