Murmur (also called breathy voice, whispery voice, soughing and susurration) is a phonation in which the vocal cords vibrate, as they do in normal (modal) voicing, but are adjusted so that a larger volume of air escapes, producing a sighing sound. A simple murmured phonation, (not actually a fricative, as a literal reading of the IPA chart would suggest), can sometimes be heard as an allophone of English between vowels, e.g. in the word behind, for some speakers.