Patent ID: 11916525
Assignee: SENNHEISER ELECTRONIC GMBH & CO. KG
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 24:
25. A device for automatically controlling loudness of an audio signal to be replayed within a vehicle, the device comprising
an automatic loudness measurer adapted for measuring the loudness of an incoming audio signal that comprises a sequence of digital audio blocks, wherein digital audio blocks having a loudness level below a silence threshold are detected and skipped in the loudness measuring, and wherein the measuring is based on the digital audio blocks having a loudness above the silence threshold;
an input circuit adapted for receiving a speed indication signal indicating a speed at which the vehicle moves;
at least one processor adapted for calculating a gain factor based on the measured loudness and the speed indication signal either using a first type of interpolation or a second type of interpolation, wherein
if the measured loudness is equal to or above a predefined first target loudness (TLamS), the gain factor is zero dB;
otherwise, if the speed indication signal indicates a speed equal to or above a defined intermediate speed, the second type of interpolation is used, wherein the gain factor is a difference between the measured loudness and a current target loudness, limited to a maximum gain, wherein the maximum gain is a defined absolute maximum gain, and the current target loudness is linearly interpolated, according to the speed, between a predefined second target loudness (TLaiS) for the speed being equal to said intermediate speed and the predefined first target loudness (TLamS) for the speed being equal to a defined maximum speed;
and otherwise, if the speed indication signal indicates a speed below the defined intermediate speed, the first type of interpolation is used, wherein the maximum gain is linearly interpolated, according to the speed, between the absolute maximum gain and zero, wherein a current maximum gain is obtained, and the gain is either equal to the current maximum gain if the measured loudness is below said second target loudness (TLaiS) reduced by the absolute maximum gain, or the gain is obtained by linearly interpolating, according to the measured loudness, between the current maximum gain and zero; and
an amplifier adapted for applying the gain factor to the audio signal to be replayed.