General:
* Chorus: This is the most common and versatile option, often used for singing voices.
* Ensemble: This implies a group of voices working together harmoniously.
* Concert: This specifically refers to a group of voices performing together musically.
More specific:
* Clamor: For a loud and confused group of voices.
* Din: For a loud, confused, and unpleasant group of voices.
* Murmur: For a soft and indistinct group of voices.
* Hubbub: For a noisy and confused group of voices.
Figurative:
* Symphony: For a harmonious and beautiful blend of voices.
* Cacophony: For a jarring and discordant group of voices.
Ultimately, the best collective noun for voices depends on the specific situation and the desired effect.