Patent ID: 8280730

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