[Strict deep bass baritone male humming only] [Lowest possible clean resonant tones] [No high-pitched vocals] [No female voice] [No breathy tones] [No lead vocalist] [No church-like or sacred humming] [Pure background atmospheric low ooo aaaa uuu mmm only] [Soft layered low echoes] Ooooooooooooooooooooooooooooooo Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu Mmmmmmmmmmmmmmmmmmmmmmmmmmmmmm Ooooooooooooooooooooooooooooooo Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu Mmmmmmmmmmmmmmmmmmmmmmmmmmmmmm Ooooooooooooooooooooooooooooooo Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa Uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu Mmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
