Patent ID: 7457757

Claim:
A method of enhancing the intelligibility of speech sounds in a communications headset, the method comprising: a) detecting an incoming signal having both speech content and ambient noise, said ambient noise including degrading artifacts, noise, and distortions; b) based upon detectable parameters in the incoming signal including central frequency and pass band contour, determining: 1) a high pass cutoff frequency value and a low pass cutoff frequency value to define a pass band filtering function that is narrow at frequencies where high and low frequency ambient noise is to be filtered out and not to be amplified and speech signals are to be amplified and increased in Signal to Noise Ratio, and 2) thereafter determining an expander function including: i) an expander threshold level below speech level and above ambient noise level, ii) an expander attack time to increase gain when speech signals are detected, and iii) an expander release time for the expander function to reduce gain when the speech signals are no longer detected; and c) sequentially 1) applying the filtering function by decreasing the low pass cut off frequency from a maximum bandwidth upper frequency limit, increasing the high pass cut off frequency from a maximum bandwidth lower frequency limit to thereby shift the central frequency of the incoming signal and, 2) raising the expander threshold, reducing the expander attack time, and reducing the expander release time; as the signal to noise ratio of the incoming signal deteriorates so that high and low frequency noise is separated from speech whereby the degraded sound quality of the incoming signal is modified in real-time to increase intelligibility as variations occur in speech sound quality of the incoming signal.