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The OICA database contains 97 vehicles in the meanwhile and will increase in future. It Maximum SPL and frequency analysis is measured. Also listening files are recorded; however we have not yet determined a common format. Therefore this data is not widely distributed. Also interior sounds are recorded to get a picture of the effect of exterior sounds on the passenger compartment. A sample is played of a vehicle that is equipped with a sounder that meets the proposed NHTSA requirements. The vehicle is prepared with the same insulation measures as applied to vehicles of the same types but with different powertrains. The sound sample shows that the interior noise increases by 3 dB(A). It is difficult to further improve the insulation measures. A sound coming from outside must not necessarily be completely suppressed, but it must be acceptable to the customer. A pleasant sound composed of harmonics is potentially better accepted. One can imagine the requirements for 8 frequency bands as a minimum requirement with the possibility for the OEM to add further sound components. The 8 prescribed frequency bands must however have a lower minimum level. This would allow the creation of a sound well recognizable from exterior, but at a low interior SPL with an acceptable quality for the passengers. |
2013-01-30 OICA Database #02 for QRTV | 2013-01-30 OICA Database #02 for QRTV
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