20100098266 | MULTI-CHANNEL AUDIO DEVICE - An audio signal enhancement device is provided. The device includes a first and a second microphone, placed as close together as possible, the first and second microphone having receiving surfaces facing in opposing directions. The first and second microphones receive a desired target audio signal originating in the proximity of the microphones and undesired noise signals not originating in the proximity of the microphones. The acoustic pressure gradient from the desired target signal between the first and the second microphones is greater than that from the noise signals. Signal processing logic is provided. The signal processing logic is configured to firstly generate a proximity-indicator signal and a pre-target-estimate signal through a combination of output from the first microphone and output of the second microphone. The signal processing logic is further configured to generate a noise-estimate signal by combining the output from the first microphone with the proximity-indicator and the pre-target-estimate. The signal processing logic is further configured to generate a target-estimate signal by combining the output from the first microphone with the proximity-indicator and the noise-estimate. The signal processing logic is further configured to provide a target signal substantially free from noise by combining the target-estimate, noise-estimate and the proximity-indicator. The embodiments also provide for a noise to signal ratio estimator that provides an indication to a user of the strength of the noise in the signal for a particular location. | 04-22-2010 |