In recent years, environmental issues have placed a big emphasis on vehicle emission and vehicle noise - including improved engine noise performance.
It is becoming increasingly important not just to reduce the radiated sound pressure, but also to improve the sound quality of vehicles for the comfort of both passengers and local residents.
In order to improve the perceived sound quality of diesel engines, Isuzu worked with sound and vibration expert, Brüel & Kjær to develop mapping of Sound Quality metrics, where noise sources can be identified based on their sound character using perception-based metrics such as loudness, sharpness and roughness.
Together, the companies also developed a new impulsiveness algorithm to clearly identify the source of impulsive noise in diesel engines. The result of the collaborative project is now the world’s first commercially available sound quality metrics mapping software for beamforming and Statistically Optimal Near-field Acoustic Holography (SONAH) systems.
Isuzu’s relationship with Brüel & Kjær goes back more than 30 years, with much of Isuzu’s equipment - such as microphones, Data Acquisition systems and wheel arrays - supplied by Bruel & Kjaer.