Patent ID: 8364477

Claim:
A method of improving intelligibility of speech that is included in audio that is emitted into a noisy environment, the method comprising: determining if one or more voice formants are present in each i th audio segment of a plurality of audio segments; if one or more formants are determined to be present in the i th audio segment: selecting a perceptual frequency scale band (L) including at least one of the one or more formants from a plurality of perceptual frequency scale bands of a perceptual scale ambient noise spectrum of the noisy environment; comparing, to a threshold, a signal-to-noise ratio of the perceptual frequency scale band, and if the signal-to-noise ratio is less than the threshold, increasing a formant enhancement gain for the perceptual frequency scale band; computing a summed signal-to-noise ratio across at least a portion of the perceptual scale ambient noise spectrum wherein a plurality of speech magnitudes in each of the plurality of perceptual frequency scale bands are used as signal magnitudes; scaling a set of overall gains that include at least the formant enhancement gains as a function of the summed signal-to-noise ratio; smoothing the set of overall gains; filtering the i th audio segment with the set of overall gains; and outputting the i th audio segment into the noisy environment.