We want to monitor aircraft noise

■A-4-1 Simple short-term measurement

The NL-42/52 series of hand-held sound level meters can be used for short-term monitoring of aircraft noise. For this purpose, install the function expansion program NX-42EX in the NL-42/52 sound level meter to provide auto store capability. Use the outdoor windscreen WS-15 and mount the meter on a tripod. It is also possible to include the level recorder LR-07 for level recording. To process recorded data on a computer, use the AS-60 data management software for environmental measurement. The AS-60 allows specifying sound event intervals for calculation, or listening to recorded real sound to determine whether the sound event is aircraft noise.

■A-4-2 Constant monitoring

Automatic constant monitoring of noise can be realized by configuring a dedicated system consisting of the environmental sound monitor NA-37 and aircraft noise processing program NX-37B. This system can automatically detect sound events and determine whether they are aircraft noise. Data can be collected on USB memory media or monitored at any time via a communications link. For data processing, the aircraft noise data processing software AS-50PA1 is used. This software can calculate Lden and other values from aircraft noise events, create reports (daily, monthly, etc.), and it also allows listening to real sound data of individual sound events. Multi-point monitoring is also supported, with the possibility to instantly switch between points for comparing data.

■A-4-3 Ground-level sound monitoring

Automatic constant monitoring of aircraft noise and ground-level noise in the vicinity of an airport can be realized simultaneously by configuring a dedicated system consisting of the environmental sound monitor NA-37 and aircraft noise processing program NX-37C. This system can automatically detect sound events and determine whether they are aircraft noise. In addition, relatively long-duration noise (ground-level noise) from aircraft taxiing, APU etc. originating within the airport site can be detected and evaluated separately as "semi-constant noise". Data can be collected on USB memory media or monitored at any time via a communications link. For data processing, the aircraft noise data processing software AS-50PA2 is used. In addition to the functions of the AS-50PA1 software, this version also can handle semi-constant noise.