Full Description

Note: Nothing in the specification supersedes applicable laws andregulations unless specificexemption has been obtained.

Note: In the event of conflict between the English and domesticlanguage, the English languageshall take precedence.

Purpose. To perform component and subsystem level validation forsqueak and rattle noises, whensubjected to a vibration spectrum comparable to 'in-vehicle'vibration.

Forward. This test is limited to detecting vibration induced noises,excited by inputs above 8hertz. Squeaks or itches excited only by slow body twist (crossditches or driveways) will not beaddressed by this test. Additionally, impact type vibrations caused bya door, hood or rearcompartment lid slam cannot be addressed by this test.

Please refer to the Squeak and Rattle Subsystem/Component TechnicalSpecification (SSTS/CTS) forthe vibration test criteria and objective in-stationary Loudnesscriteria or subjective evaluationcriteria.

Applicability. This procedure is applicable to any automotivecomponent or subsystem where squeaksand rattles are a concern and the vibration environment can besimulated.

Definitions.

PSD. Power Spectral Density is a plot of acceleration versusfrequency. The acceleration valueshave the units of (m/s²) ² /Hz.

N-Sigma Clipping. N-Sigma clipping occurs when the peak amplitude iscut-off based on a normalstatistical distribution limit. Often 3-sigma clipping is selected.

Instationary Loudness. Loudness (sones) involves linearization ofsubjective perception of theloudness of acoustic signals. The unit of loudness, the sone,corresponds to a sine tone offrequency 1 kHz and a level of 40 dB. Tones twice as loud (perceivedas such) have the loudnessvalue 2 sones, tones three times as loud have the value 3 sones, andso on.

N10 Loudness. N10 Loudness is a statistically calculated Loudnessvalue based on the 90thpercentile value of the time varying loudness values. The 90thpercentile means that 10% percent ofthe population has a value greater than the N10 value and 90% of thepopulation has a value that isless.