How do you ensure that it’s not too loud in the vehicle?

For quite some time now, interior noise in cars has been getting quieter. The once dominant sound of the internal combustion engine is now in the background, and other noise sources have moved to the forefront. Due to their high RPM, alternators contribute up to 40% of this total noise inside the vehicle. In order that this noise doesn't become to dominant or disturbing, the alternator is subjected to an acoustical emission test.

During the examination, random accoustical samples are collected by the test stand
over a microphone portal. The subsequent signals are analyzed and evaluated, and the results are classified on a PASS/FAIL basis and stored in the database.

To make the testing as simple, accurate and fast as possible, imc automated the entire test sequence. The system consists of a modular imc measurement system and customized software based on the imc STUDIO software platform.

Application Note: Acoustical power analysis on automotive alternators