Abstract:Abstract: The source of gear whine in automotive transmission is identified. Firstly, the whine noise is tested in the Hemi-anechoicroom.Through frequency spectrum analysis and noise contribution analysis ,the whine spectrum is found. The problem is special that different gears have the same mesh frequency. Aim at this special problem, the acoustic camera is used and the source of the gear whine is found.Finally,through FEM the nature frequency of the transmission house is caculated.The transmission house is resonated in some frequency.The research provides experiment basis for modification of the gear design parameter and the structure of the transmission house to achive low noise transmission.