Architectural Acoustics: Simplified Measuring Techniques

摘要

A preliminary study of the state of the art in architectural acoustics revealed a definite need for an improvement of methods for in situ acoustical measurements. A study was therefore made to develop and demonstrate measuring techniques and equipment that are simple, portable, and reasonably accurate. Techniques for measuring three fundamental acoustical parameters are presented, and extensive background material is provided to familiarize the reader with the principles and terminology of architectural acoustics. Methods, utilizing a memory oscilloscope, were developed for measuring the transmission loss of walls and partitions and for measuring the reverberation time of large rooms. A standard method for obtaining sound-absorption coefficients and measuring a wall material's specific impedance is presented, showing the expedience of the Smith Chart for making impedance calculations. Experimental measurements were made to evaluate and demonstrate the methods, and the results are in the form of tables, graphs, and oscilloscope traces. All three methods fulfill the task objectives. Elaborate setups are not required, and transmission losses can be determined at a fraction of the cost of measurements by present standard techniques. (Author)