Audio dynamic range compression characteristics based on an interpolating polynomial

An audio signal level compressor is presented, in this paper, which is based on the approximation algorithm using an interpolating polynomial. To implement a compression characteristic in a digital audio system, a power calculation with fractional numbers is required and it is difficult to be performed directly in a digital signal processing system. We introduce a polynomial expression to approximate the power operation then the gain calculation is easily performed with a number of additions, multiplications and a division. Newton's interpolation formula is used to calculate the compression characteristics in a very short time.