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Document Title | Japan suggestions for AVAS sound requirements | ||||||||
Reference Number | GTRQRTV-03-10 | ||||||||
Date |
15 May 2013
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Summary | Presentation with recommendations for approaching vehicle audible systems for use in electric and other quiet vehicles. | ||||||||
Source(s) | JASIC | ||||||||
Rulemaking Area(s) | QRTV-GTR | ||||||||
Meeting(s) | |||||||||
Downloads | |||||||||
UNECE server | .pdf format | ||||||||
Excerpts from session reports related to this document | |||||||||
GTRQRTV | Session 3 | 16-18 Apr 2013 |
Japan presented results from various examinations on the requirements for the sound quality of AVAS. The examination result in the following suggestions: • Sound must be emitted from at least 2 1/3 octave bands Both suggested requirements have been verified with various forms of testing including lab and jury testing. The mentioned overall level shall be determined as a function of the vehicle stopping distance. However the required SPL to fulfill that target is not yet decided at the moment and needs further investigation. 1 kHz to 5 kHz is detectable for people with normal hearing; elderly people have difficulties with the higher frequencies. OICA: on the first glance it appears as if it positive under environmental aspects to use as few energy as possible when producing a sound that is detectable because this reduces the overall SPL. But this has nothing to do with annoyance. Even a low SPL signal can be an issue for public. We must be careful not being too scientific when determining suitable frequencies, leaving aside the subjective aspect of public perception. CLEPA: the frequency band from 1 kHz-5 kHz as identified by JAPAN is not only best for detectability but also for locatibility. ISO: how precise do you need to define the content within one individual 1/3 octave band? J: This question needs to be discussed in ISO. OICA: In fact, looking at page 6 of the presentation, the shown curve may be interpreted to contain more than only 2 prominent frequencies, but 5 or even 6, depending on how narrow the definition of one frequency is taken. A clear definition is needed. This does also contain the opportunity to leave room for flexibility to the OEM as long as he designs sound outside of the defined requirements. |
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