. Altec's Bob Bird, a true genius in electronic design and application, developed the first properly operating automatic level control for paging systems called NOALA - Noise-Operated-Automatic-Level-Adjustment. The NOALA worked so well that many are still in operation all over the world. Only the advent of digitally-controlled sound processing e equipment made it possible to improve upon his design.
Senses changes in the ambiant environmental noise. Automatically adjusts system gain as required to maintain intelligibility. Operator's Manual Link: nleinternet.net/alteclansingunofficial/proelectronics/prosignalprocessing/ Technical Letter Link: nleinternet.net/alteclansingunofficial/publications/techletters/TL_219.pdf This item is brand new in a brown box. It comes only with the peripherals shown in the photos.