Audio‐frequency atmospherics
EVERETT T. BURTON, E. M. Boardman · Transactions American Geophysical Union · 1934
A year ago one of us presented a paper (E. T. Burton and E. M. Boardman, Audio‐frequency atmospherics, Proc. I. R. E., v. 21, pp. 1476–1494, 1933) a feature of which was some sound‐records of musical atmospherics. Since that date additional records have been obtained. Before proceeding with the demonstration of these records it would be well to review the subject. Audio‐frequency atmospherics may be divided into two general groups, musical and non‐musical. The non‐musical atmospherics appear much as does detected radio‐frequency static. They consist audibly of rumbling sounds in the low‐frequency, crackling in the intermediate‐frequency, and frying or hissing in the high‐frequency range. These sounds contain little that is striking to the ear and may be passed with brief comment. Sounds which possess a definite tonal quality have been termed musical, and with them this paper is concerned.