Initial Inspection and Diagnostic Overview: Overview

Noise, Vibration And Harshness (NVH) is any audible or tactile disturbance which detracts from the customer's appreciation of the vehicle. NVH concerns are becoming more important as vehicles become more sophisticated and passenger comfort levels increase.
- Noise is defined as sounds not associated with the operation of passenger compartment equipment that interfere with customer's satisfaction.
- Vibration is defined as tactile impulses felt by the customer through the steering wheel, pedals, seat, floor pan or armrest.
- Harshness is defined as a ride quality issue in which the customer feels that the vehicle response to the road surface is sharply transmitted to the customer. Harshness is usually associated with tires, suspension and body mounting.

All internal combustion engines and drivelines produce some noise and vibration; operating in a real world environment adds noise that is not subject to control. Mufflers and dampers are used to reduce these to acceptable levels.