Calibration and Uncertainty Estimation for The Reference Sound Source in Reverberation Room.

Since the determination of room acoustic parameters are requesting the sound power of the sound source. Few trials to publish the way of calibration and uncertainty estimation in details for the reference sound source were performed. So, it is very interesting to find a way to calibrate the reference sound source that can be used in different acoustic measurements. Also, there is a need to find the value uncertainty of due to the calibration of reference sound source. Sound power level of any sound source can be determined by means of sound pressure level measurements performed in accordance to relevant ISO standards. The calibration of reference sound source according to ISO 6926 may be implemented in a hemianechoic or reverberation room. The method and way of sound power calculations which may depend on number of microphones, their positions and place of measurements stated. Measurements of sound pressure level, reverberation time and background noise level were performed using traceable instruments by direct method in ISO3741. Then the calculation of sound power level in 1/3 octave band frequency was carried out for the reference sound source side by side with uncertainty contributions resulting from measurements. The values of uncertainty σR0 σomc respectively are in order of magnitude of 0.4 and 0.07 dB. The total uncertainty lies within the range of 0.7-1.0dB in the 1/3 octave band frequency from 125Hz to 10000Hz. [ABSTRACT FROM AUTHOR]