The insertion loss IL for octave band
center frequencies spanning from 63 to 250 Hz can be expressed as
In order the study the behavior of the noise, the overall noise level should be discretized to certain octave band
. Since most of the commercially available noise measuring instruments measure noise in the 1/3 octave band
, it is convenient to discretize the noise in the 1/3 octave band
The measured A-weighted SPL was averaged and separated from the background noise for each one-third octave band
for wind speeds in the range from 4 to 11m [s.sup.-1].
The vibrations of the vehicle during a test run with 160 km/h have been analysed by one-third octave band
In this standard, the equivalent continuous downwind octave band
sound pressure level at a receiver, [L.sub.fT,i], is calculated for each point source, for its image sources, and for the eight octave bands
with nominal frequencies from 63 Hz to 8 kHz, by the following equation:
According , some of them are "relatively simple engineering methods based on A-weighted levels or on octave bands
on one side" (e.g.
After individually analyzing the micro-recordings by octave band
(3) and making a pressure comparison in pascals with the last values obtained in the calibration section, the SPL data is stored in vectors (both the data and the microrecordings).
Noise level (total, the third-octave band spectra and octave band
spectra) was measured along each section of road under 120 singly passing cars and 80 multiple-axle heavy vehicles (according to the Statistical Pass-By method).
Using the tables in AHRI 885, one can estimate the room sound levels only if one has octave band
sound power data as an entering argument.
Vibration Decay with respect to Distance in terms of the 1/3 Octave Band