Patent ID: 8345893
Filing Date: 2013-01-01
Classification: H03G,H04S

Abstract:
1. A sound volume controller, comprising: a level adjustment section that adjusts a level of an input audio signal and outputs the adjusted input audio signal as an output audio signal; a level detection section that detects the level of the input audio signal; a volume value detection section that detects a volume value set by a user; a coefficient table storage section that stores a coefficient table which describes a relation between levels of the output audio signal and levels of the input audio signal; a coefficient table change section that changes a coefficient of the coefficient table stored in the coefficient table storage section in accordance with the volume value detected by the volume value detection section; a setting section that sets an amount of level adjustment of the level adjustment section in accordance with the level of the input audio signal detected by the level detection section and the coefficient table; wherein the coefficient table includes a linear range in which an amount of change in the level of the input audio signal is same as an amount of change in the level of the output audio signal, a small range which is smaller than the linear range in the level of the input audio signal, and a large range which is larger than the linear range in the level of the input audio signal; wherein the small range and large range are compression ranges in which the amount of change in the level of the output audio signal is smaller than the amount of change in the level of the input audio signal; wherein the coefficient table change section changes the coefficient of the coefficient table so that a ratio of the amount of change in the level of the output audio signal to the amount of change in the level of the input audio signal in the compression ranges becomes small in accordance with a decrease of the volume value.