Journal Article
Free-Field Technique for Secondary Standard Calibration of Microphones
Journal of the Audio Engineering Society · Volume 4 · Issue 3 · pp. 110–115 · July 1956
Abstract
The acoustic environment required for the performance of free-field secondary standard microphone calibrations is examined. The technique includes automatic compensation for variations in sound output level versus frequency of the sound source. Size and orientation of the standard and object microhones and mounting are considered with a view toward minimizing disturbances in the sound field, and resulting calibration errors, arising from reflections at high frquencies. Maximum and minimum working distances from sound sources of various dimensions necessary to maintain plane-wave free-field conditions are given for a variety of microphone types. The accuracy limits of the calibration method are indicated.
