The Harvard sentences, sometimes called Harvard lines,[1] is a collection of 720 sample phrases, divided into lists of 10, used for standardized testing of
Voice over IP,
cellular, and other
telephone systems. They are phonetically balanced sentences that use specific phonemes at the same frequency they appear in English.
IEEE Recommended Practice for Speech Quality Measurements[2] sets out seventy-two lists of ten phrases each, described as the "1965 Revised List of Phonetically Balanced Sentences (Harvard Sentences)." They are widely used in research on telecommunications, speech, and acoustics, where standardized and repeatable sequences of speech are needed. The Open Speech Repository[3] provides some freely usable, prerecorded
WAV files of Harvard Sentences in American and British English, in male and female voices.
Harvard lines are also used to observe how an actor's mouth can move when they are talking. This can be used when creating more realistic
CGI models.[1]