JPH11154841A - Intra-vehicle sound field controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a driver able to hear the alarm sound of an emergency automobile or the like, even when the sound field level of a vehicle audio equipment is raised. SOLUTION: The alarm sound or the like of the emergency automobile is inputted by a microphone 1 on the outer surface of an automobile, digitally converted in an A/D conversion part 2, inputted to a discrimination part 4 and compared with specified sound read from a storage part 3. When it matches and is larger than a required reference value, the sound field level of the car audio equipment is lowered by a sound volume adjustment part 8. When the level of the alarm sound is lowered, the sound field level is restored. The original sound field level is stored in a memory part 5. Also, the frequency of the sound outside of the car is analyzed in a frequency analysis part 7, and it can be discriminated as the specified sound when the frequency matches with the frequency stored in the storage part beforehand. Also, the sound field level can be lowered in the case that the analyzed frequency is continuously and gradually rises and it can be returned to the original sound field level, when it starts to lower.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-vehicle sound field control device, which lowers the volume of a car audio device by detecting an alarm sound of an emergency vehicle, a horn sound of a subsequent vehicle, or a warning sound of a railroad crossing. About things.

[0002]

2. Description of the Related Art The performance of car audio devices installed in automobiles has been improved, and a higher sense of reality can be obtained by increasing the volume. However, increasing the volume makes it difficult for the driver to hear sounds outside the vehicle, for example,
While noticing that the emergency car is approaching while sounding the alarm sound, not noticing that the signal changed from red to blue, the following car is prompted to start at horn, or the alarm starts to sound at the railroad crossing However, there are problems such as not being noticed, disturbing the surroundings, and failing to keep the driver's safety.

[0003]

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to increase the volume of a car audio device in a vehicle so that a driver can hear necessary outside sound even when listening. I do.

[0004]

In order to achieve the above object, in the in-vehicle sound field control device according to the present invention, a microphone (hereinafter abbreviated as a microphone) provided outside the automobile.
And a determining unit for determining the loudness of a specific sound from the microphone;
A volume adjustment unit that adjusts the volume of the car audio device installed in the vehicle based on the signal from the determination unit,
When the loudness of the specific sound is equal to or more than a required value, the volume of the car audio device is reduced.

When the volume of the specific sound from the microphone falls below a required value, the volume of the car audio device is returned to the original level by the volume adjusting section.

A memory unit for storing a value before the volume of the car audio device is lowered is provided, and when the volume of the specific sound falls below a required value, the volume of the car audio device is adjusted based on the data read from the memory unit by the volume adjustment unit. The sound volume of the device may be restored.

[0007] Alternatively, a storage section for storing a reference value of the volume is provided, and the loudness of the specific sound is compared with the data read from the storage section by the discriminating section. The volume of the car audio device is reduced by the volume adjusting unit, and when the volume is lower than the reference value, the volume is returned to the original volume.

A clock section for starting time measurement based on a signal from the discriminating section when the loudness of the specific sound is equal to or more than a required value, and outputting a signal when a required time elapses;
The volume of the car audio device may be returned to the original volume by the volume controller based on a signal from a clock unit.

Alternatively, a frequency analysis unit for analyzing the frequency of the signal from the microphone is provided, and the frequency of the specific sound is stored in the storage unit, and the frequency analyzed by the frequency analysis unit is read from the storage unit. The volume of the car audio device may be reduced by the volume adjuster when the frequency matches the frequency.

Alternatively, the volume of the car audio device is reduced by the volume control unit when the frequency analyzed by the frequency analysis unit continuously increases, and based on the volume when the frequency starts to continuously decrease. I will put it back.

The microphone has directivity, is mounted rearward on the back of the vehicle, and a specific sound (horn sound) from the vehicle behind is input, and the loudness of the specific sound is greater than a required value. In this case, the volume of the car audio device may be reduced by the volume adjusting unit.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments with reference to the drawings. FIG. 1 is a block diagram of a main part of an embodiment of an in-vehicle sound field control device according to the present invention. Figure 1
Is a microphone, which is installed outside the car. An A / D converter 2 converts a signal from the microphone 1 into a digital signal. Reference numeral 3 denotes a storage unit for storing specific sounds such as a vehicle horn sound, a railway crossing alarm sound, an ambulance alarm sound, a police patrol car alarm sound, and a reference value for determining the sound volume outside the vehicle. Reference numeral 4 denotes a discrimination unit that discriminates a specific sound from the A / D conversion unit 2, determines a volume outside the vehicle, determines a frequency, and the like. 5
Is a memory unit for storing a value before lowering the volume of the car audio device installed in the automobile. Reference numeral 6 denotes a clock section, which starts timing with a signal from the determination section 4 and outputs a signal when a required time has elapsed. Reference numeral 7 denotes a frequency analysis unit that analyzes the frequency of a signal (external sound) from the A / D conversion unit 2. Reference numeral 8 denotes a volume adjustment unit that adjusts the volume (sound field level) of the car audio device. An output unit 9 is a sound output unit of the car audio device. A control unit 10 controls each unit of the apparatus.

Next, the operation of the in-vehicle sound field control device according to the present invention will be described. The microphones 1 are provided on the back and front of the car. When an emergency vehicle such as an ambulance or a patrol car approaches while sounding an alarm, this alarm is input to the microphone 1 and a signal from the microphone 1 is transmitted to the A / D converter 2.
Is converted into a digital signal by the control unit 10 and the determination unit 4
To enter. Then, it is compared with the specific sound read from the storage unit 3 to determine from the coincidence that the alarm sound is an alarm sound of an ambulance or a patrol car. If the control unit 10 determines that the volume is larger than the reference value,
To reduce the sound signal level of the car audio device to, for example, about 70% to 50%, lower the sound field level in the car (the sound output level of the output unit 9), and there is an emergency car nearby. Make the driver aware of this, and focus on outside noise. When the emergency vehicle moves away and the alarm sound becomes smaller than the reference value or when the alarm sound stops, the sound output level is returned to the original level by the sound volume adjustment unit 8 based on the signal from the determination unit 4.

Further, the microphone 1 picks up the horn sound of the vehicle around the own vehicle or the sound of the alarm at the railroad crossing, and performs the same determination as above. Reduce the sound field level in the car. In this case, a microphone having directivity may be used, and the microphone may be attached to the rear of the vehicle so as to face rearward, and the horn sound of the vehicle behind the own vehicle which is hard to notice may be sensed. In addition, the sound field level immediately before the operation of the sound volume adjusting section 8 (lowering the sound field level) is stored in the memory section 5,
The data in the memory unit 5 may be read when the sound outside the vehicle is reduced or stopped, and the sound field level may be returned to the original level by the volume adjusting unit 8 based on the data.

Alternatively, the clock is started by the clock section 6 based on the signal from the discriminating section 4 and a signal is output when a required time, for example, 30 seconds, has elapsed. May be restored. in this way,
By temporarily lowering the sound field level in the vehicle, the driver is made aware that there is a change in the situation outside the vehicle, and the volume of the car audio device can be reduced by manual operation.

The above-described method of determining the specific sound outside the vehicle may be determined by frequency analysis. That is, an external sound signal input from the microphone 1 via the A / D conversion unit 2 is input to the frequency analysis unit 7 via the control unit 10,
A frequency analysis is performed, and this data is input to the determination unit 4.
Then, the frequency data of the specific sound which has been set and stored in advance from the storage unit 3 via the control unit 10 is read out, and the frequency analysis unit 7
Then, it is determined whether the alarm sound is an alarm sound of an ambulance, a patrol car, a horn of a car, a railway crossing, or the like.

Further, the sound field level can be lowered when an emergency vehicle approaches while emitting a warning sound, and the sound field level can be restored when the emergency vehicle moves away. That is, the signal from the microphone 1 is frequency-analyzed by the frequency analysis unit 7 via the control unit 10, and this frequency is determined by the determination unit 4. If the frequency continuously increases, the volume is adjusted by the signal from the determination unit 4. The sound field level is lowered by the unit 8, and the sound field level is restored when the frequency starts to decrease continuously. This is because when the emergency vehicle approaches, the distance from the sound source gradually decreases, so the time required for the sound to reach gradually decreases, the apparent frequency gradually increases due to the Doppler effect, and when the emergency vehicle moves away, the sound source This is because the distance becomes gradually longer, so that the time required for the sound to reach gradually increases, and the apparent frequency gradually decreases.

[0018]

As described above, according to the in-vehicle sound field control device of the present invention, an alarm sound of an emergency vehicle, a horn sound of a surrounding vehicle, a sound of a railway crossing alarm, and the like are detected. Changes in the surrounding conditions accompanied by these outside sounds that could not be heard because the sound field level of the car audio devices was raised because the output level of the car audio device was lowered and the driver could easily notice the sound outside the vehicle. Can quickly respond, respect traffic rules, and at the same time protect their own safety.

[Brief description of the drawings]

FIG. 1 is a main part block diagram of an embodiment of an in-vehicle sound field control device according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 microphone 2 A / D conversion unit 3 storage unit 4 determination unit 5 memory unit 6 clock unit 7 frequency analysis unit 8 volume adjustment unit 9 output unit 10 control unit

Claims (9)

[Claims] 1. A microphone provided outside a car, a discriminator for discriminating a loudness of a specific sound from the microphone, and a volume of a car audio device installed in the car based on a signal from the discriminator. An in-vehicle sound field control device, comprising: a sound volume adjustment unit for adjusting the sound volume of the car audio device when the volume of the specific sound is equal to or more than a required value. 2. The in-vehicle sound field control device according to claim 1, wherein the volume of the car audio device is returned to the original volume by the volume adjustment unit when the volume of the specific sound becomes equal to or less than a required value. 3. A memory unit for storing a value before lowering the volume of the car audio device, wherein when the volume of the specific sound falls below a required value, the data read from the memory unit by the volume controller is added to the data. 3. The in-vehicle sound field control device according to claim 2, wherein the volume of the car audio device is returned to the original level based on the condition. 4. A storage unit for storing a reference value of a volume,
The discrimination unit compares the loudness of the specific sound with the data read from the storage unit, and when the specific sound is larger than the reference value, lowers the volume of the car audio device by the volume adjusting unit and becomes smaller than the reference value. 4. The in-vehicle sound field control device according to claim 1, wherein the sound volume is returned to an original volume when the vehicle is turned on. 5. A timer is started based on a signal from the discriminating unit when the loudness of the specific sound exceeds a required value,
4. A clock section for outputting a signal after a lapse of a required time, wherein the volume of the car audio device is returned to the original volume by the volume adjusting section based on a signal from the clock section.
The in-vehicle sound field control device according to the above description. 6. A frequency analysis unit for analyzing a frequency of a signal from the microphone is provided, and the frequency of the specific sound is stored in the storage unit, and the frequency analyzed by the frequency analysis unit is read from the storage unit. 6. The in-vehicle sound field control device according to claim 1, wherein the volume of the car audio device is reduced by the volume adjustment unit when the frequency matches the frequency. 7. A frequency analysis unit for analyzing a frequency of a signal from the microphone, wherein the volume of the car audio device is reduced by the volume adjustment unit when the frequency of the signal continuously increases. The in-vehicle sound field control device according to the above description. 8. The system according to claim 1, wherein when the frequency of the signal from the microphone starts dropping continuously, the volume of the car audio device is restored by the volume control unit based on the signal from the frequency analysis unit. 7. The in-vehicle sound field control device according to 7. 9. The microphone according to claim 1, wherein said microphone has directivity, is mounted rearward on the back of the car, and receives a specific sound from a car behind.
7. The in-vehicle sound field control device according to 3, 4, 5, or 6.