OF all problems involving noise measurement, the human ear is the final judge and the court of last resort. In most situations, as in the case of the motor-car buyer, it is the untrained ear of the average customer that ultimately passes judgment. Likewise in all instrument calibration, it is necessary in the final analysis to depend upon the ear as a basis.
For this reason the measurement of noise must be so conducted that results and predictions will agree with ear judgments. A discussion is given of the various characteristics of noise that the ear recognizes, that is, loudness, pitch, quality, and discomfort or annoyance. The physical quantities corresponding to these psychological characteristics are discussed, and also methods of converting from one set of quantities to the other.
The experimentally established relationships between pitch, loudness, and annoyance are given. A recent series of tests, relating the internal resistance of panel-damping treatments to their effectiveness as judged by ear, is reported.
A brief discussion of the technique of noise measurement is given, with special emphasis upon instruments and instrumental methods suitable to coincide with ear judgments.
