Sound output device, sound output system, and output sound control method with appropriately controllable volume, and recording medium

1. A sound output device comprising:

first circuitry, connected to a first audio device, configured to output sound based on sound output data via the first audio device according to first sound volume data;

second circuitry connected to a second audio device, the second circuitry including an amplifier that amplifies sound to be output from the second audio device:

a control line that allows one-way communication from the first circuitry to the second circuitry; and

a user interface configured to receive a user input of operation for changing the first sound volume data,

wherein the sound output data and the first sound volume data are transmitted from the first circuitry to the second circuitry through the control line, and

wherein the first circuitry is further configured to

change the first sound volume data according to the user input of operation that is received, and

transmit the first sound volume ta having been Changed to the second circuitry,

wherein the second circuitry is configured to

receive, from the first circuitry, the sound output data and the first sound volume data,

output sound based on the sound output data that is received, via the second audio device, according to the first sound volume data that is received,

control a value of second sound volume data set for the amplifier to be a fixed value,

receive the user input of operation for changing the first sound volume data from the user interface, and

transmit the operation for changing the first sound volume data to the first circuitry, through another control line that allows communication from the second circuitry to the first circuitry.

2. The sound output device of claim 1 , wherein the first circuitry can be removed from or attached to the sound output device, or controlled to be enabled or disabled, and

the second circuitry controls the value of the second sound volume data to be a previously stored value, when the first circuitry is removed or controlled to be disabled.

3. A sound output system comprising:

the sound output device of claim 1 ,

wherein the sound output device is an electronic whiteboard.

4. A sound output system comprising:

the sound output device of claim 1 ;

a plurality of audio devices including the first audio device and the second audio device.

5. A method for controlling sound output, performed by a sound output device including first circuitry connected to a first audio device and second circuitry connected to a second audio device, the second circuitry including an amplifier that amplifies sound to the output from the second audio device, the method comprising:

determining whether the first circuitry is enabled;

transmitting, based on a determination that the first circuitry is enabled, from the first circuitry to the second circuitry, first sound volume data stored for the first circuitry, and sound output data, through a control line that allows one-wav communication from the first circuitry to the second circuitry;

outputting sound based on the sound output data, via the second audio device, according to the first sound volume data;

controlling a value of second sound volume data set for the amplifier to be a fixed value;

receiving, at the second circuitry, a user input of operation for changing the first sound volume data from a user interface;

transmitting the operation for changing the first sound volume data to the first circuitry, through another control line that allows communication from the second circuitry to the first circuitry;

changing, at the first circuitry, the first sound volume data according to the user input of operation that is received; and

transmitting, from the first circuitry to the second circuitry, the first sound volume data having been changed.

6. A non-transitory recording medium storing a plurality of instructions which, when executed by one or more processors, cause the processors to perform a method for controlling sound output, performed by a sound output device including first circuitry connected to a first audio device and second circuitry connected to a second audio device, the second circuitry including an amplifier that amplifies sound to be output from the second audio device, the method comprising:

determining whether the first circuitry is enabled;

transmitting, based on a determination that the first circuitry is enabled, from the first circuitry to the second circuitry, first sound volume data stored for the first circuitry, and sound output data, through a control line that allows one-way communication from the first circuitry to the second circuitry;

outputting, sound based on the sound output data, via the second audio device, according to the first sound volume data;

controlling a value of second sound volume data set for the amplifier to be a fixed value;

receiving, at the second circuitry, a user input of operation for changing the first sound volume data from a user interface;

transmitting the operation for Changing the first sound volume data to the first circuitry, through another control line that allows communication from the second circuitry to the first circuitry;

changing, at the first circuitry, the first sound volume data according to the user input of operation that is received; and

transmitting, from the first circuitry to the second circuitry, the first sound volume data having been changed.