The results obtained by different workers show the spread of measure in the sound pressure level about the same kind of materials. This fact may be attributed to the relative small size of the room which easily generated the standing wave.
This report intended to obtain the basic data for the rational selection of receiving position.
A loudspeaker was used to generate sound in the second floor as a transmitting room. Sound pressure levels were measured over a grid of measuring points in a receiving room (the first floor). On gride planes across the width of the room (each plane includes 36 points) the level were cubic spline interpolated between measuring points, a computer being used .
The wide range distribution of sound pressure level was observed at low frequency. The lowest sound pressure level was taken at the center of the room below 200 Hz. The sound pressure level was reletively uniform above 250 Hz. The distribution of sound pressure level from cross planes was not so fluctuated as that of the plane.