1. Field of the Invention
This invention relates to a sound-correction system, a recording medium on which a sound-correction program is recorded, a sound-correction method and a sound-correction apparatus.
2. Description of the Related Art
When listening to music or the like using the audio apparatus installed inside a vehicle, it sometimes becomes difficult to hear the sound from the car-audio system due to various noise from the outside surroundings when the vehicle is moving.
For example, when traveling over a bad road, the road noise that occurs between the tires and the road surface becomes large, and it may not be possible to hear very much music from the car audio at all.
Particularly, in the case where the vehicle is an automobile with a roof, when the roof is open, the noise sensed inside the vehicle from the outside surroundings becomes even larger.
Conventionally, as measures taken against this kind of noise, the audio apparatus installed in the automobile performed control that automatically changed the volume of the audio apparatus when the power windows of the vehicle were opened or closed for example, refer to Japanese Laid-Open patent application no. H7-94985.
One kind of noise that occurs when moving is road noise that occurs between the tires and the road surface. This road noise is mainly low-frequency noise such as occurs when traveling at slow speed over a bad road, however, when traveling on a freeway, middle- to high-frequency noise occurs due to the sound of the wind.
With the conventional technology described above, the sound is changed simply when the power windows are opened or closed, so correction is not performed when low-frequency noise occurs due to road noise, or when high-frequency noise occurs due to the sound of the wind when traveling on a freeway, so there was a problem in that the sound becomes difficult to hear.