The previously reported ‘hissler’ phenomenon has been studied by means of broad band VLF data from antarctic ground stations and from the polar‐orbiting Ogo 2 and Ogo 4 satellites. Hisslers are quasi‐periodic broad band VLF auroral noises that typically present a falling‐tone characteristic on frequency‐time spectrograms and often appear in minute‐long sequences with spacing between individual bursts of the order of 2 s at a given frequency. The falling tones do not usually overlap in time; instead a new one tends to develop as the previous one ends. The falling‐tone noises are a feature of auroral hiss, in that they occur during time intervals when hiss is observed at ground stations and in portions of space where hiss is observed on polar‐orbiting satellites. A survey was made of 1500 Ogo 4 magnetic loop antenna records from the vicinity of Alaska and of the Antarctic. Hisslers were observed at various points from 58° invariant latitude to the mid polar cap, occurring on approximately 40% of the passes. Hisslers were observed from Ogo 4 in various local time and latitudinal sectors of the auroral oval, but there was some evidence of a concentration near Λ=75° and in the premidnight sector. At Byrd, Antarctica (L ∼ 7), hisslers are frequently observed prior to the expansion phase of a substorm and during a part of the expansion phase when hiss is detectable on the ground. The study suggests that centers of hissler activity are present on nearly all days, that they may be somewhat localized in space, and that they may be active for periods of several hours.