Patent ID: 8321215

Claim:
A method of improving the perceived quality of audible speech represented by a speech signal, the speech signal comprising first signal components in a first frequency band and second signal components in a second frequency band, the method comprising: estimating the average power of the first signal components and the average power of the second signal components; selecting a first gain factor such that on application of the first gain factor to the second signal components to generate adjusted second signal components, the ratio of the average power of the first signal components to the average power of the adjusted second signal components would be a first predetermined value, the first predetermined value being such as to inhibit perceptual distortion of the audible speech; applying said first gain factor to the second signal components to generate the adjusted second signal components, thereby forming an improved speech signal comprising the first signal components and the adjusted second signal components; and outputting said improved speech signal to an audible speech output device to convert said improved speech signal into audible speech.