The Type 1564-A Sound and Vibration Analyzer, Figure 1-1,is a portable instrument for the frequency analysis of voltages having components between 2.5 cps and 25 kc. The high input impedance of the analyzer permits the direct connection of piezoelectric transducers for the analysis of high- level acoustical spectra. For low levels, the analyzer can be operated in conjunction with a sound-level meter or a vibration meter. Designed for either manual or automatic tuning, the analyzer can be used with a graphic level recorder, such as the General Radio Type 1521, to produce continuous plots of level as a function of frequency.