Battery operated; c/o bio-acoustic simulator w/test frequencies of 125 hz to 8k hz; calibration of 60 db hz l, three led left, right, and power and two electret elements; includes a octave monitor w/five led's 0.5k hz, 1k hz, 2k hz, 4k hz and 8k hz; for daily biological test of audioeters and continuously monitor rom noise in octanes
