Partnership for Air Transportation Noise and Emissions Reduction

NTL-AVIATION-AVIATION ; NTL-ENERGY AND ENVIRONMENT-ENERGY AND ENVIRONMENT ;

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This report documents a study to investigate human response to the low-frequency

content of aviation noise, or low-frequency noise (LFN). The study comprised field

measurements and laboratory studies. The major findings were:

1. Start-of-takeoff-roll, acceleration down the runway, and thrust reversal generate

high levels of LFN (below 200 Hz) at critical distances from runways (around

3000 ft in the study) which can be annoying to people living around airports.

2. Hubbard exterior sound level criteria works well as a first level assessment tool

for vibration/rattle due to LFN.

3. A-weighted Sound Pressure Level (LAmax) and C-weighted Sound Pressure

Level (LCmax) metrics correlate well with laboratory based subjective response

to indoor aircraft noise when LFN levels are low to moderate. The same holds

for rattle annoyance (again for low to moderate level LFN). Also, multiple low

level LFN events may cause rattle (i.e. simultaneous multiple runway

operations).

4. When high levels of LFN are present, Tokita & Nakamura thresholds with CWeighted

Sound Exposure Level (LCE) metric should be used as an indicator of

potential for LFN annoyance. The low-frequency noise based metrics did not

perform as well as LCE. Data lower than 50 Hz is needed to assess

vibration/rattle annoyance.

5. The risk of window rattle is lowered with preload and avoiding resonance

response in the design. Outdoor-Indoor Transmission Class (OITC) is a better

rating for rattle prone applications than Sound Transmission Class (STC)

commonly used in rating windows for transmission loss.

US Transportation Collection