6. Conclusion

In the field of transport noise, a number of indices and tools are available that are sufficiently well adapted to characterize vehicle emissions and noise levels in the environment. Their operational use is strongly guided by European regulations and their national transpositions. The effects of transport noise, whose social cost is close to 1% of GDP, are now well documented; their link with acoustic ambiences could be improved, without making the guide values set by the WHO, which are already optimal, any more stringent. In the future, technological developments should make it possible to further reduce noise emissions from vehicles and aircraft, already well under control. As far as housing is concerned, efforts to improve thermal insulation, encouraged by the public authorities despite their cost, have resulted in beneficial acoustic attenuation for residents. However, many homes are...