Special sound producing device

1. A special sound producing device which is loaded in a vehicle, and provides information to a vehicle crew by a special sound, comprising:

a plurality of speakers that become power sources of the special sound; and

a control unit that generates frequency signals to make the special sound output from the plurality of speakers respectively,

wherein when one information to be transmitted to the vehicle crew is transmitted by the special sound from the plurality of speakers, the control unit makes frequencies of the frequency signals, sound pressures of the special sound or output timings to the speakers of the frequency signals to be different between the plurality of speakers,

wherein the plurality of speakers are two speakers, and

when the sound pressures of the special sound are made to be different, the control unit equalizes the output timings of the frequency signals and the frequencies of the frequency signals to the two speakers, gradually decreases a sound pressure control ratio which indicates either of a duty ratio of a frequency signal or an on duty, which is the duty ratio during an on state, of the frequency signal to one speaker from a first predetermined value to a second predetermined value which is smaller than the first predetermined value, and gradually increases the sound pressure control ratio of a frequency signal to the other speaker from the second predetermined value to the first predetermined value.

2. The special sound producing device according to claim 1 , wherein the plurality of speakers are placed at a meter unit in which vehicle instruments are loaded, and

information to promote attention by a warning sound is provided to the vehicle crew.

3. A special sound producing device, which is loaded in a vehicle, and provides information to a vehicle crew by a special sound, comprising:

a plurality of speakers that become power sources of the special sound; and

a control unit that generates frequency signals to make the special sound output from the plurality of speakers respectively,

wherein when one information to be transmitted to the vehicle crew is transmitted by the special sound from the plurality of speakers, the control unit makes frequencies of the frequency signals, sound pressures of the special sound or output timings to the speakers of the frequency signals to be different between the plurality of speakers,

wherein the plurality of speakers are two speakers, and

when the output timings are made to be different, the control unit equalizes the sound pressures of the special sound and the frequencies of the frequency signals, makes an output timing of the frequency signal to one speaker and an output timing of a frequency signal to the other speaker overlapping, and makes the output timing of a frequency signal to the other speaker delayed for more than a predetermined time than the output timing of the frequency signal to the one speaker.

4. A special sound producing device which is loaded in a vehicle, and provides information to a vehicle crew by a special sound, comprising:

a plurality of speakers that become power sources of the special sound; and

a control unit that generates frequency signals to make the special sound output from the plurality of speakers respectively,

wherein when one information to be transmitted to the vehicle crew is transmitted by the special sound from the plurality of speakers, the control unit makes frequencies of the frequency signals, sound pressures of the special sound or output timings to the speakers of the frequency signals to be different between the plurality of speakers,

wherein the plurality of speakers are two speakers, and

when the frequencies of the frequency signals are made to be different, if a frequency of a frequency signal to one speaker is f1, the control unit sets a frequency f2 of a frequency signal to the other speaker as a value calculated by an equation f1:f2=n:n+1, in which n is an integer of 1 or more.

5. A special sound producing device which is loaded in a vehicle, and provides information to a vehicle crew by a special sound, comprising:

a plurality of speakers that become power sources of the special sound; and

a control unit that generates frequency signals to make the special sound output from the plurality of speakers respectively,

wherein when one information to be transmitted to the vehicle crew is transmitted by the special sound from the plurality of speakers, the control unit makes frequencies of the frequency signals, sound pressures of the special sound or output timings to the speakers of the frequency signals to be different between the plurality of speakers,

wherein the plurality of speakers are two speakers, and

when the frequencies of the frequency signals are made to be different, if a frequency of a frequency signal to one speaker is f1, the control unit sets a frequency f2 of a frequency signal to the other speaker as a value except values calculated by an equation f1:f2=n:n+1, in which n is an integer of 1 or more.

6. A special sound producing device which is loaded in a vehicle, and provides information to a vehicle crew by a special sound, comprising:

a plurality of speakers that become power sources of the special sound; and

a control unit that generates frequency signals to make the special sound output from the plurality of speakers respectively,

wherein when one information to be transmitted to the vehicle crew is transmitted by the special sound from the plurality of speakers, the control unit makes frequencies of the frequency signals, sound pressures of the special sound or output timings to the speakers of the frequency signals to be different between the plurality of speakers,

wherein the plurality of speakers are two speakers, and

when the output timings are made to be different, the control unit equalizes the frequencies of the frequency signals to the two speakers, makes an output timing of a frequency signal to one speaker and an output timing of a frequency signal to the other speaker overlapping, and makes the output timing of the frequency signal to the other speaker delayed for less than a predetermined time from the output timing of the frequency signal to the one speaker.

7. A special sound producing device which is loaded in a vehicle, and provides information to a vehicle crew by a special sound, comprising:

a plurality of speakers that become power sources of the special sound; and

a control unit that generates frequency signals to make the special sound output from the plurality of speakers respectively,

wherein when one information to be transmitted to the vehicle crew is transmitted by the special sound from the plurality of speakers, the control unit makes frequencies of the frequency signals, sound pressures of the special sound or output timings to the speakers of the frequency signals to be different between the plurality of speakers,

wherein the plurality of speakers are two speakers, and

when the output timings are made to be different, the control unit repeats an action of outputting a frequency signal to one speaker after having output a frequency signal to the other speaker, prohibits the output of the frequency signal to the one speaker in the output timing of the frequency signal to the other speaker and prohibits the output of the frequency signal to the other speaker in the output timing of the frequency signal to the one speaker.

8. The special sound producing device according to claim 3 , wherein the plurality of speakers are placed at a meter unit in which vehicle instruments are loaded, and

information to promote attention by a warning sound is provided to the vehicle crew.

9. The special sound producing device according to claim 4 , wherein the plurality of speakers are placed at a meter unit in which vehicle instruments are loaded, and

information to promote attention by a warning sound is provided to the vehicle crew.

10. The special sound producing device according to claim 5 , wherein the plurality of speakers are placed at a meter unit in which vehicle instruments are loaded, and

information to promote attention by a warning sound is provided to the vehicle crew.

11. The special sound producing device according to claim 6 , wherein the plurality of speakers are placed at a meter unit in which vehicle instruments are loaded, and

information to promote attention by a warning sound is provided to the vehicle crew.

12. The special sound producing device according to claim 7 , wherein the plurality of speakers are placed at a meter unit in which vehicle instruments are loaded, and

information to promote attention by a warning sound is provided to the vehicle crew.