Since 1966, aircraft noise around Zurich Airport has been measured. Fourteen permanently installed measurement stations, called Noise Monitoring Terminals (NMTs), are currently in operation.
Each station consists of:

• a microphone mounted on a mast
• a device for measuring sound levels
• a weather station for wind direction and wind speed
• a computer for data processing
• a modem for data transmission
• the required power supply

The microphones record all sounds at the location around the clock. Flight schedule data and flight tracks are transmitted to a web application via the mobile network.
A dedicated algorithm automatically identifies which sounds originate from aircraft. To achieve this, the measurement data is compared with flight movements. Data quality is checked through software functions and random manual checks.

The results are published monthly in the noise reports. In addition, average maximum levels are calculated for each aircraft type. These values form the basis of the noise charge model, which encourages the use of quieter aircraft.

• Noise Charges

Noise exposure maps

Aircraft noise exposure at Zurich Airport is calculated by Empa and presented in noise exposure maps. The levels of all overflights are averaged over the entire year. The colored areas in red, yellow and green show the regions where the calculated aircraft noise exposure exceeds the limit values. However, aircraft noise may also be perceived outside these colored areas. The legal terms, calculation rules and limit values are defined in the Noise Protection Ordinance.

• Noise Abatement Ordinance