Over the past year numerous communications systems have been evaluated in the NEL High Level Noise Facility. This system, consisting of 16 low‐frequency and 38 high‐frequency horns driven by a 10 000 w amplifier, can reproduce jet aircraft noises to a group of six listeners at levels up to 140 db (over‐all,Cweighting). Two different mobile (flight deck) radio communications systems, a series of developmental sound powered phones, and a Helicopter PA rescue announcing system have been evaluated. In addition, limits of face‐to‐face communications have been established. Satisfactory communications using the best available acoustic components can be carried on in jet noise when both talkers and listeners are in 135‐db levels. Flight deck radio communication sets now in use in the fleet are usable up to levels of 125 db. Developmental models of sound powered phone equipments are usable up to 120 db, although present equipment is good only to 100 db. With no electronic or acoustic aids satisfactory face to face communications between a talker and listener are possible in jet noise up to 97 db at 3 ft, 91 db at 6 ft, and 85 db at 12 ft. Selected data (1) on different noises, (2) when either talker or listener are in quiet, and (3) when ear protection is used also will be discussed.