Road noise
The automotive industries of Japan,
United States and Europe are persisting in their
efforts to further abate noise from automobiles.
JARI examines noise measuring methods and make predictions of
the effects of noise regulations by applying computer simulation.
The results of these studies have been employed as basic reference data
for the drafting of Japanese and international regulations for automotive noise.
Moreover, our test data have been utilized in the global discussion to make the quiet
electric vehicles recognizable to pedestrians by adding an artificial sounding function.
(1) International harmonization of noise test methods
To achieve an effective reduction of automotive noise,
noise generation is assessed using a test method that reflects the on-road
running conditions of vehicles, and countries are working together to develop
such a noise test method.
JARI supplies its test data and analytical results to ISO and UN/ECE/WP29/GRB for
the drafting of an international noise regulation.
Vehicle noise testing
(2) Prediction by computer simulation
To introduce a comprehensive traffic noise reduction program,
it is imperative to predict the effect of a conceived noise
reduction program in advance.
JARI aims to make reliable noise predictions using its original
simulation method that combines a simulation of realworld traffic
flow and a sound pressure waveform synthesizing technique.
JARI traffic noise simulation model