PUBLIC ADDRESS INTELLIGIBLITY SYSTEM

Intelligibility of a human voice projected by a loudspeaker in an environment of high ambient noise is enhanced by amplifying formants (26, 28, 30) of the voice. Because intelligibility of the human voice is derived largely from the pattern of frequency distribution of voice formants, selective enhancement of the formants provides much more readily understandable speech in the presence of high background noise with but minimal increase in amplitude of the speech. Formants are processed by individually selecting them in a spectrum analyzer (42, 124) and individually amplifying (50, 58, 74, 80, 140 through 146) and selectively weighting (56, 57, 78, 82) them before recombining processed formants and unprocessed base band voice components (130) to provide an output signal (116) of greatly improved intelligibility.