scope:

Note: Nothing in this specification supersedes applicable laws and regulations unless a specific exemption has been obtained.

Note: In the event of a conflict between the English and domestic language, the English language shall take precedence.

Purpose.

This procedure describes a laboratory method for evaluating the loudness of the audible click produced when inserting the latchplate into the buckle of the seat belt system and the audible noise produced when the seat belt retractor is extracted.

Foreword.

The noise of the seat belt buckle during latching is evaluated using the Zwicker loudness method. This evaluation is intended to ensure that the audible click produced when inserting the latchplate into the seat belt buckle gives the customer adequate feedback that the latchplate is securely engaged in the buckle. In addition, this evaluation is intended to ensure that the sound produced when extracting the webbing from the seat belt retractor is not excessively loud. 

Applicability.

Passenger vehicles and on-road vehicles equipped with seat belt buckles.