JPH066156A - Voice output level controller - Google Patents

Abstract

PURPOSE:To control the sound volume to a proper sound volume at all times and to improve the sound leakage to surrounding simultaneously by adjusting automatic answering telephone set the sound volume of a voice reproduction device in response to a level of surrounding level in a train or the like in which a change in surrounding environmental noise is large. CONSTITUTION:A reproduction signal is outputted from a mechanism 1 at voice reproduction and a reproduction voice processing circuit 2 processes the signal and the sound volume is adjusted manually by a variable resistor 3, the signal is given to a power amplifier 5 via a GCA 4, which drives a head phone 6 and a voice signal is outputted. Simultaneously a microphone 7 collects the environment noise around the controller by the microphone 7 and amplified by a microphone amplifier 83, converted into a DC voltage by a detection circuit 9, the voltage is inputted to a control terminal of the GCA 4 via the switch 10 and the output level of the reproduced voice signal is adjusted to a proper level automatically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voice output level control device for varying the output level of reproduced voice according to the level of ambient noise around the device.

[0002]

2. Description of the Related Art In a variable audio reproducing apparatus, an apparatus having a dedicated circuit for cutting only a high frequency range of audio has been developed in order to reduce sound leakage from headphones and the like.

[0003]

However, in the above configuration, for example, the noise in the train has a noise difference of about 20 to 30 dB between when the vehicle is waiting for departure and when the vehicle is traveling at 100 km / h. At the volume level set in the train when traveling at 100 km, the volume may feel high when the vehicle is stopped and sound may leak to the surroundings. Therefore, there is a problem that the volume must be manually lowered every time the vehicle is stopped.

The present invention solves the above-mentioned problems, and in a train or the like where the surrounding environmental noise changes greatly, the output level of the audio reproducing device is automatically adjusted according to the environmental noise level, so that it is always appropriate. It is an object of the present invention to provide a sound output level control device having a characteristic that the sound volume is controlled to a proper level and, at the same time, sound leakage to the surroundings is improved.

[0005]

In order to achieve this object, the present invention provides a sound collecting means for collecting environmental noise around the apparatus, and a detection circuit for detecting the environmental noise collected by the sound collecting means. A level control means for adjusting the output level of the reproduced sound according to the detection output level of the detection circuit.

[0006]

With the above arrangement, the present invention makes it possible to automatically control the output level of the reproduced voice so that the volume becomes appropriate according to the change of the environmental noise.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an overall block system diagram of an audio output level control device of the present invention. In FIG. 1, 1 is a CD
Alternatively, a tape driving mechanism, 2 is a reproduced sound processing circuit, 3 is a volume that varies the level of the output signal of the reproduced sound output circuit 2, and 4 is a gain control amplifier (hereinafter referred to as GCA) that controls the gain level. Reference numeral 5 is a power amplifier, 6 is a headphone for outputting sound, 7 is a microphone for collecting environmental noise around the device, and 8 is a microphone 7.
A microphone amplifier that amplifies the environmental noise picked up in, 9 is a detection circuit that converts the output signal of the microphone amplifier 8 into a DC voltage,
10 is a switch.

Next, the operation of the present invention will be described. During playback, the switch 10 in FIG.
CA4 is a line amplifier having a certain gain, and the output level of the reproduced sound is manually initialized by the volume 3. Next, when the switch 10 is turned on, the environmental noise picked up by the microphone 7 is converted into a DC voltage by the detection circuit 9 and supplied to the GCA 4. The GCA 4 varies the audio output level initially set by the volume 3 with a predetermined time constant according to the DC voltage from the detection circuit 9, amplifies it with the power amplifier 5, and outputs it from the headphones 6.

As described above, according to this embodiment, by providing the microphone 8 for picking up the environmental noise and the GCA 4, the output level of the reproduced voice is automatically set to an appropriate value according to the level of the environmental noise. Can be adjusted to.

[0011]

As described above, according to the present invention, the reproduction volume is automatically adjusted according to the level of the environmental noise even in the train where the surrounding environmental noise changes greatly. It has a characteristic that the sound volume is increased, and at the same time, sound leakage to the surroundings is also improved.

[Brief description of drawings]

FIG. 1 is a block diagram of an audio output level control device according to an embodiment of the present invention.

[Explanation of symbols]

 1 sound reproduction mechanism 2 reproduction sound processing circuit 3 volume 4 gain control amplifier 5 power amplifier 6 headphone 7 microphone 8 microphone amplifier 9 detection circuit 10 switch

Claims (1)

[Claims] 1. A sound collecting unit for collecting environmental noise around the apparatus, a detection circuit for detecting the environmental noise collected by the sound collecting unit, and a reproduced voice according to a detection output level of the detection circuit. And an audio output level control means for varying the output level of the audio output level control device.