Praat

Praat (the Dutch word for "talk") is a free scientific computer software package for the analysis of speech in phonetics. It was designed, and continues to be developed, by Paul Boersma and David Weenink of the University of Amsterdam. It can run on a wide range of operating systems, including various versions of Unix, GNU/Linux, Mac and Microsoft Windows (95, 98, NT4, ME, 2000, XP, Vista, 7). The program also supports speech synthesis, including articulatory synthesis.