AN ENVIRONMENTAL NOISE LEVEL ESTIMATION APPARATUS, A COMMUNICATION APPARATUS, A DATA TERMINAL APPARATUS, AND A METHOD OF ESTIMATING AN ENVIRONMENTAL NOISE LEVEL

摘要

ABSTRACT OF THE DISCLOSUREAN ENVIRONMENTAL NOISE LEVEL ESTIMATION APPARATUS, A COMMUNICATION APPARATUS, A DATA TERMINAL APPARATUS,AND A METHOD OF ESTIMATING AN ENVIRONMENTAL NOISE LEVEL A level of a sound signal including a voice signaland an environmental noise signal is detected and a level(power level) is sampled in response to a clock signal. Itis detected whether the presently sampled level increasesfrom the previously sampled level. An environmental noise level is estimated such that, when the presently sampledlevel increases from the previously sampled level,difference between the presently and previously estimatedenvironmental noise levels is lower than a predeterminedvalue. When the presently sampled level decreases, the presently estimated environmental noise level is equalized to the presently sampled value. The environmental noise level is estimated only when the detected level is smallerthan the predetermined value. The sampling interval may besmaller than 250 cosec. Estimation may be stopped in the presence of voice signal. An environmental noise level may be estimated when the detected level is smaller than a reference. A communication apparatus and data terminalincluding the An environmental noise level estimationapparatus are also disclosed.Figure 1.