ECHO BARRIER H-SERIES User Manual page 16

Especially important is that noise reduction of 20 dB
equates to energy reduction of 99% (Table 5), yet the
remaining 1% of energy represents 25% of the noise level
perceived by the human ear.
Decibel
reduction (dB)
10
20
30
40
KEY FACTORS IN SUCCESSFUL NOISE MITIGATION
There are 4 key factors that determine the noise mitigation
achieved by a barrier of any kind:
1. Geometry — The position of the barrier in relation to
the noise source.
2. Noise absorption — The degree to which the barrier
absorbs sound, rather than simply reflecting it. When
noise is reflected, it can reverberate, amplifying noise
pollution.
Table 5. Noise Reduction
Energy
reduction (%)
90
99
99.9
99.99
PAGE 16 — ECHO BARRIER • USER MANUAL — REV. #0 (09/14/18)
PERFORMANCE GUIDE
Noise reduction
as perceived by the human ear
Sounds 50% as loud (reduction of 50%)
Sounds 25% as loud (reduction of 75%)
Sounds 12.5% as loud (reduction of 87.5%)
Sounds 6.25% as loud (reduction of 93.75%)
3. Barrier mass — Greater mass offers greater noise
mitigation (i.e. results in greater transmission loss),
but for the sake of practicality, a barrier also needs to
remain manageable in terms of its size and weight,
especially if it is to be portable.
4. Barrier aesthetics — If barriers are manufactured to
a high standard and present a professional image, the
perceptions of their performance can be considerably
enhanced.