liminary criteria are found in (1) the agreement of the observations ABSORBING POWER OF WALL-SURFACES 15 obtained at one sitting, (2) the agreement of the results obtainedon different nights and after the lapse of months, or even years, bythe same observer under similar conditions, and (3) the… … Fig. 1. Chronograph, battery, and air reservoir, the latter surmountedby the electro-pneumatic valve and organ pipe. and the result of such examination is as follows: Each determinationbeing the mean of about twenty observations under conditions suchthat the audible duration of the residual sound…
Architectural acoustics
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