METHOD, DEVICE, AND PROGRAM FOR IMPROVING VOICE SPECTRUM, AND STORAGE MEDIUM STORED WITH THE PROGRAM

摘要

PROBLEM TO BE SOLVED: To suppress noise in all bands included in a voice spectrum. SOLUTION: A voice spectrum improving method is provided which performs a spectrum calculating process of analyzing and calculating a frequency spectrum included in a voice signal of fixed-time length from the voice signal, a 1st nonlinear converting process of emphasizing the calculated spectrum according to how the spectrum intensity is large, a smoothing 1st linear filtering process of performing linear smoothing filtering on a frequency axis for the spectrum after the 1st nonlinear converting process, a 2nd nonlinear converting process of performing a nonlinear converting process to canceling the nonlinear conversion done by the 1st nonlinear converting process, and a 2nd linear filtering process of performing a reverse smoothing filtering process for canceling smoothing filtering characteristics after the smoothing 1st linear filtering process.