CXVI.The transmission of sound through partitions. II.—Vibrating partitions

Abstract

Abstract The paper is a continuation of previous work on the measurement of the transmission of sound through partitions of various materials. In the method the test panel covers an aperture in a sound-proof wall between two rooms. A beam of sound is directed obliquely upon one side of the partition, and upon the other side measurements are made of the sound transmitted. Whilst the earlier work was concerned largely with panels of a felt-like nature, the present paper gives results for partitions—ranging from a sheet of paper to single and double board partitions and to a brick wall—which transmit sound to a greater or lesser extent by vibration. It is found that, in spite of partition vibration, the sound is transmitted as a beam, and measurements of transmission ratio are largely independent of the position in the transmitted beam at which measurements are taken. To reduce errors associated with single-point observations, a moving microphone was found to be advantageous. As an additional aid in avoiding...