JPS6180997A - Loudspeaker with sound volume adjuster - Google Patents

Abstract

PURPOSE:To make effective sound volume adjustment by establishing a means to generate an electrical signal obtained by deducting an electrical signal corre sponding to the sound to be amplified from an electrical signal corresponding to sound level which includes circumstantial sound and the sound amplified by the loudspeaker with a sound volume adjuster. CONSTITUTION:The output of the electrical signal generating source 1 is con nected to the first input of a volume adjuster 2 and the first input of an echo canceller 7. The output of the volume adjuster 2 is amplified by the first ampli fier 3 and drives an electroacoustic transducer (loudspeaker) 4. An electroacoustic transducer (microphone) 5 receives circumstantial sounds includ ing the output of the electroacoustic transducer 4. The sound is amplified 6 and connected to the second input of echo canceller 7. The echo canceller 7 issues the signal obtained by deducting the output of the electrical signal generat ing source 1 from the output of the amplifier 6, and supplies it to the sound volume adjuster 2 as an adjustment input. By this procedure, the sound adjust ment is effectively and automatically done according to the real circumstantial noises.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic volume control circuit for a loudspeaker, and more particularly to a circuit that automatically adjusts the volume of amplified sound from a speaker in accordance with the level of ambient noise.

[Conventional technology]

It is appropriate to adjust the volume from the loudspeaker according to the level of ambient noise, and to increase the loudspeaker volume when the surrounding noise is large.

FIG. 2 is a block configuration diagram showing the configuration of a conventional loudspeaker with a volume controller. In this device, the acoustic-electrical transducer 5
The level of the noise is measured, and the volume is adjusted using the volume controller 2 based on an electric signal corresponding to the noise level.

[Problem that the invention seeks to solve]

In such a conventional device, the input to the acoustic/electrical converter 5 is not only the ambient noise but also the sound output from the electrical/acoustic converter 4, and the amplification is performed according to the true ambient noise. Volume adjustment becomes impossible.

An object of the present invention is to eliminate this drawback and provide a loudspeaker with a volume controller that can adjust the loudspeaker volume according to the actual noise level.

[Means for solving problems]

The present invention is a loudspeaker with a volume controller that automatically adjusts the magnitude of an electrical signal corresponding to the magnitude of the sound to be amplified using an adjustment signal thereof, and is a means for solving the above-mentioned problems. , the magnitude of the electrical signal corresponding to the magnitude of the ambient sound including the ambient sound generated due to the amplified sound, minus the magnitude of the electrical signal corresponding to the magnitude of the amplified sound. The present invention is characterized by comprising means for generating an electrical signal as the adjustment signal.

It is effective to use an echo canceller as a circuit for reducing two electrical signals.

[Effect]

The output from the means for generating the adjustment signal is an electrical signal of a magnitude corresponding to the magnitude of the ambient sound, which does not include the ambient sound caused by the amplified sound, and the volume controller automatically adjusts the volume based on this electrical signal. This amplified sound is then amplified.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A device according to an embodiment of the present invention will be explained below based on the drawings.

FIG. 1 is a block configuration diagram showing the configuration of the apparatus of this embodiment. The configuration of this embodiment device will be explained based on FIG. This embodiment device includes an electrical signal generation source 1, a volume controller 2, a first amplifier 3, an electrical/acoustic transducer 4, and an acoustic/acoustic converter 4.
electrical converter 5, second amplifier 6, and echo canceller 7
Equipped with.

The output of the electrical signal source 1 is connected to the first input of the volume controller 2 and the first input of the echo canceller 7, the output of the volume controller 2 is connected to the human power of the first amplifier 3, and the output of the volume controller 2 is connected to the human power of the first amplifier 3. The output of 3 is connected to the input of electro-acoustic transducer 4. The output of the acoustic-to-electrical transducer 5 is connected to the human power of a second amplifier 6, and the output of the second amplifier 6 is connected to the second input of the echo canceller 7. The output of the echo canceller 7 is connected to a second input of the volume controller 2.

Next, the operation of this embodiment device will be explained based on FIG.

The electric signal from the electric signal generation source 1 passes through the volume controller 2 and the first amplifier 3, and is output as sound from the electric-acoustic converter 4. Ambient noise including this output sound is input to the echo canceller 7 via the acoustic/electrical converter 5 and the second amplifier 6. The echo canceller 7 also receives an electric signal from the electric signal source 1, and the echo canceller 7 inputs the electric signal output from the electric signal source 1 from the electric signal output from the second amplifier 6. The removed signal is given as an adjustment input to the volume controller 2.

〔Effect of the invention〕

As explained above, the present invention allows the volume to be automatically adjusted according to the true ambient noise when the sound reproduced by a magnetic recorder or the like that outputs a set volume is emitted through a loudspeaker. This has the effect of making it possible to effectively adjust the volume without human intervention.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an apparatus according to an embodiment of the present invention. FIG. 2 is a block configuration diagram showing the configuration of a conventional device. 1... Electric signal generation source, 2... Volume adjuster, 3.6
...Amplifier, 4...Electric/acoustic converter, 5...
Acoustic/electrical converter, 7...Echo canceller.

Claims (2)

[Claims] (1) In a loudspeaker system with a volume controller that automatically adjusts the magnitude of an electrical signal corresponding to the loudness of the sound to be amplified using the adjustment signal, ambient sound generated due to the sound to be amplified; means for generating, as the adjustment signal, an electrical signal having a magnitude obtained by subtracting the magnitude of the electrical signal corresponding to the magnitude of the amplified sound from the magnitude of the electrical signal corresponding to the magnitude of the ambient sound including A public address system with a volume controller, characterized by: (2) The loudspeaker with a volume adjuster according to claim (1), wherein the means for generating the adjustment signal includes an echo canceller.