Acoustic Measurements - As Tested by Western Electro Acoustic Lab, Santa Monica, CA

Laboratory Measurements

Freq (Hz)	250	500	1000	2000	4000
AC* (0.6)	.21	.64	.88	.72	.58
STL** (25)	23	23	24	36	36

* Absorption Coefficient Per ASTMC 423-90a

** Sound Transmission Loss Per ASTME-413 procedure E90-90

Field Measurements:

-Transmission Loss

12 ft High Wall	Albany Airport, NY	Broadband Aircraft Engine Noise - 16 dBA
8 ft High Wall	Culver City, Ca	Electrical Transformer Noise 120 & 240 Hz - 13dBA
20 ft High Wall	Chula Vista Ampitheater, CA	Broadband Noise Transmission Loss - 26 dba

-Echo reduction

20 ft High Wall	Chula Vista, CA @ 100Hz 50 % Concrete & 50% QUILITE	-10dBA
20 ft High Wall	Chula Vista, CA Broadband Echo 100% Concrete	See Fig. A
20 ft High Wall	Chula Vista, CA Broadband Echo 50% Concrete & 50% QUILITE	See Fig. B

Figure 1

Echo From 100% Concrete Wall Surface Area

Figure 2

Echo From 50% Concrete & 50% QUILITE Wall Surface Area

Figure 3

Combination reflection graph of broad band sound between a concrete wall and a combination QUILITE wall

Figure 2 shows that the nominal echo from the combination wall surface has approximately half the intensity of the 100% concrete wall (Figure A). This indicates the net reflection efficiency of QUILITE is significantly lower than implied by the Lab measured absorbtion coefficient