Jamieson, Fausset and Brown on 1 Corinthians 14:10

10. it may be--that is, perhaps, speaking by conjecture. "It may chance" (1Co 15:37).

so many--as may be enumerated by investigators of such matters. Compare "so much," used generally for a definite number left undefined (Ac 5:8; also 2Sa 12:8).

kinds of voices--kinds of articulate speech.

without signification--without articulate voice (that is, distinct meaning). None is without its own voice, or mode of speech, distinct from the rest.