An experimental investigation of ground board mounted microphones for outdoor noise measurement

This paper reports an experimental investigation on the use of ground board mounted microphones for making outdoor noise measurements. The experiments utilized a 400 mm diameter thin metal ground board into which a probe microphone was flush mounted at a number of different radii. The ground board was placed on the floor of an anechoic chamber and the noise level from a source at a fixed height was measured for a large number of different ground board orientations. These measurements were used to assess the variation in the sound pressure level over the ground board.