AMPLIFIER WITH ADJUSTMENT OF THE AUTOMATIC SOUND LEVEL

• US 20180097496A1
• Filed: 01/19/2016
• Published: 04/05/2018
• Est. Priority Date: 01/19/2015
• Status: Active Grant

• Current Assignee: Devialet
• Original Assignee: Devialet
• Inventors: MENDES, Eduardo, BERGRE, Julien, CALMEL, Pierre-Emmanuel
• Granted Patent: US 10,141,905 B2
• Time in Patent Office: Days
• CPC Class Codes: H03G 7/002 in untuned or low-frequency amplifiers, e.g. audio amplifiers H03G7/007, H03G7/001, H03G7/008, H03G7/02, H03G7/06 take precedence
• CPC Class Codes: H03G 7/007 of digital or coded signals

Abstract

The method for adapting the volume gain (G_{Volume appliqué}) to be applied by an amplifier to at least one audio signal (S_{Audio 1} to S_{Audio N}) to be reproduced, according to the desired volume gain (G_{Volume désiré}) selected by a user includes the following steps:

• • calculating a standardized total slow sound level (N_SLTN) from the at least one signal (S_{Audio 1} to S_{Audio N}) to be reproduced;
  • calculating a maximum slow volume gain (G_VolLentmax) and a minimum slow volume gain (G_VolLentmin) as the quotient of the product of the desired volume gain (G_{Volume désiré}) by dividing a maximum slow gain (G_Lentmax) or respectively a minimum slow gain (G_LentMin) by the standardized total slow sound level (N_SLTN);
  • determining a first minimum out of the desired volume gain (G_{volume désiré}) and the maximum slow volume gain (G_VolLentmax);
  • determining a second minimum out of the desired volume gain (G_{Volume désiré}) multiplied by a maximum volume gain (G_maxVolume) and the minimum slow volume gain (G_volLentMin);
  • determining, as a slow volume gain (G_{Volume Lent}), the maximum of the first and second previously determined minima;
  • calculating the volume gain applied (G_{Volume appliqué}) according to the slow volume gain (G_{Volume Lent}).

Claims

1. A method for adapting the volume gain to be applied by an amplifier to at least one audio signal to be reproduced, according to the desired volume gain selected by a user, including the following steps:

calculating a standardized total slow sound level from the signal(s) to be reproduced;

calculating a maximum slow volume gain and a minimum slow volume gain as the quotient of the product of the desired volume gain by a maximum slow gain, respectively by a minimum slow gain, divided by the standardized total slow sound level;

determining a first minimum out of the desired volume gain and the maximum slow volume gain;

determining a second minimum out of the desired volume gain multiplied by a maximum volume gain and the minimum slow volume gain;

determining, as a slow volume gain, the maximum of the first and second previously determined minima; and

calculating the applied volume gain according to the slow volume gain.

2. The method according to claim 1, wherein the step for calculating the standardized total slow sound level includes, for the or each audio signal to be reproduced, calculating a slow sound level specific to the audio signal, such as the average of the levels of the audio signal of each source over a long duration.

3. The method according to claim 2, wherein it includes at least two audio signals to be reproduced, and the standardized total slow sound level is a function of each of the slow sound levels.

4. The method according to claim 2, wherein the long duration is greater than 1 second.

5. The method according to claim 1, wherein the applied volume gain is the product of the slow volume gain multiplied by a peak volume gain having a value lower than or equal to 1 depending on fluctuations of the sound level of the or each sound signal over a short duration strictly shorter than the long duration.

6. The method according to claim 5, wherein the calculation of the peak volume gain includes the following steps:

calculating a standardized total fast sound level from the signal(s) to be reproduced;

calculating an expansion coefficient equal to the quotient of the product of the standardized total slow sound level multiplied by a maximum peak gain divided by the standardized total fast sound level; and

calculating the peak volume gain as the minimum of the expansion coefficient and the value 1.

7. The method according to claim 6, wherein the step for calculating the standardized total fast sound level includes, for the or each audio signal to be reproduced, calculating a fast sound level specific to each audio signal, such as the average of the levels of the audio signal of the source over the short duration.

8. The method according to claim 7, wherein it includes at least two audio signals to be reproduced, and the standardized total fast sound level is a function of each of the slow sound levels.

9. The method according to claim 5, wherein the short duration is less than 1 second.

10. An amplifier including means for adapting the volume gain to at least one audio signal to be reproduced, according to the desired volume gain selected by a user, including:

means for calculating a standardized total slow sound level from the signal(s) to be reproduced;

means for calculating a maximum slow volume gain and a minimum slow volume gain as the quotient of the product of the desired volume gain by a maximum slow gain, respectively by a minimum slow gain divided by the standardized total slow sound level;

means for determining a first minimum out of the desired volume gain and the maximum slow volume gain;

means for determining a second minimum out of the desired volume gain multiplied by a maximum volume gain and the minimum slow volume gain;

means for determining, as a slow volume gain, the maximum of the first and second previously determined minima; and

means for calculating the volume gain applied according to the slow volume gain.