Airplane Quieting II—Specification of Acceptable Noise Levels

Abstract

Abstract A procedure for determining the effect of aircraft noise on the ability of passengers to converse during flight is presented. Account is taken of the distance apart of the talker and listener, of the voice intensity (i.e. loud talking, shouting, etc.), and of the character of the noise in the cabin. Experimental data are given to confirm the validity of the method. A “speech-interference level” is defined as the arithmetic average of the levels in the three octave bands between 600 and 4800 cycles per sec. Maximum values of speech-interference levels for which satisfactory speech intelligibility is obtained are given.