| 摘要 |
PURPOSE:To control the compression ratio/of a signal level corresponding to a loudness level which is the psychological amount of a human and the characteristics of a speaker. CONSTITUTION:First, the impulse response of the speaker 9 is convoluted in an FIR type filter 2. When audio signals are supplied from an audio signal input means 1, an amplification factor detection means 10 detects the amplification factor of an amplifier 8. Then, a.loudness computing means 4 computes the loudness level by the amplification factor and the output result of the FIR type filter 2. A selection means 5 selects a multiplication coefficient corresponding to a loudness level value from a storage part 6 and supplies the value to a multiplier 7. The amplifier 8 amplifies the multiplied audio signals and supplies them to the speaker 9 and acoustically natural sound is reproduced. |
