peep [peeps](feeble utterance or complaint) noun [UK: piːp] [US: ˈpiːp]
susurrus(whispering or rustling sound) noun [UK: sˈuːzʌrəs] [US: sˈuːzɜːrəs]
whisper [whispers](act of speaking in a quiet voice) noun [UK: ˈwɪ.spə(r)] [US: ˈwɪ.spər]Don't raise your voice above a whisper. = No eleves tu voz más fuerte que un susurro.