What is a type of singing where the voice imitates instruments?

A type of singing where the voice imitates instruments is known as "vocalese." In this style, singers use their voices to replicate the sounds of various instruments, often incorporating techniques like pitch variation, rhythmic patterns, and breathing techniques to create a musical effect similar to that of instruments. Vocalese is commonly found in jazz and contemporary music, where vocalists perform intricate melodies and solos inspired by instrumental pieces.