hiss fizz whiz sizzle fizzle swish whirr spit whistle rasp wheeze whisper shrill blow seethe siss whoosh whizz crackle buzz boo hoot jeer shout down gasp pant hyperventilate puff heave croak snore breathe audibly breathe heavily breathe noisily catch your breath breathe roughly catch one's breath breathe huff drone hum whir bumble reverberate bombilate bombinate burr fuzz purr susurrate warble whish zip murmur mumble mutter mouth say softly speak softly say in hushed tones say in muted tones speak in muted tones speak sotto voce talk low say sotto voce utter under the breath say under one's breath speak in hushed tones sigh More