A case study of interior booming noise control in an HEV

An interior booming noise issue occurred during a development stage of an HEV program. Based on the noise generation mechanism, the root cause analyses were carried out. It is found that the interior booming noise was mainly induced by the excessive second order noise from the exhaust tail pipe. The effort was focused on the noise source reduction. Using acoustic simulation and parameter optimization, a Helmholtz resonator was designed and proposed. The measured results based on the proposed design showed that the interior sound pressure peak level responsible for the booming noise sensation was reduced significantly. The effectiveness of the proposed design was validated by vehicle testing and subjective evaluations.