[Annoyance due to street traffic and aircraft noise].

Annoyance is an important criterion to assess the health-impairing effects of noise. Affected are especially communications, due to speech interference, as well as relaxation and sleep. The extent of annoyance increases with rising noise load in the street traffic as well as in the air traffic. Air-traffic noise in residential areas should lie below NNI-values of 35; values of above 45 NNI result in a heavy noise load and require sound-protection measures. Street-traffic noise in residential areas should not surpass an Leq value of 60 dB(A) in daytime and 50 dB(A) at night; Leq values of more than 65 dB(A) are qualified as considerable annoyance and are thus critical. In recreation areas the threshold limits should be 5 dB(A) below these values, whereas for shops and offices at main thoroughfares values higher by 5 dB(A) can be tolerated. The noise load should first of all be diminished by stricter regulations for vehicles as well as by measures regarding traffic organization. Furthermore, noise-conscious driving is recommended. Very great traffic noise also requires sound protection measures.