Patent ID: 9735746
Date: 2017-08-15
CPC Classifications: H03G

Claim:
1. An automatic loudness control system comprising: a controllable gain/attenuation unit that includes a gain/attenuation control input, an audio signal input, an audio signal output, and whose gain/attenuation between the audio signal input and the audio signal output is controlled by the gain/attenuation control input signal; a gain/attenuation evaluation unit that is connected to the gain/attenuation control input of the controllable gain/attenuation unit and that has an actual-loudness input and a desired loudness input; an actual-loudness evaluation unit that is connected to the audio signal input of the controllable gain/attenuation unit and that provides the actual-loudness input to the gain/attenuation evaluation unit; and a desired-loudness evaluation unit that is connected to the desired-loudness input of the gain/attenuation evaluation unit and that has a volume control input; in which the gain/attenuation evaluation unit is configured to control the controllable gain/attenuation unit dependent on signals supplied to the volume control input of the desired-loudness evaluation unit and the audio signal input of the controllable gain/attenuation unit, wherein the desired-loudness evaluation unit comprises a first conversion unit that converts a volume setting into a signal representing a desired loudness in which the actual-loudness evaluation unit further comprises a psychoacoustic modeling unit, and in which the psychoacoustic modeling unit employs a psychoacoustic masking model on the input signal.