Summary
the instrument described delineates on a cathode ray screen the decay of sound energy density as a function of time after the sound source is turned off in a room. The output from the pick-up microphone after suitable amplification and rectification is fed to a logarithmic stage to enable an energy range of 55 db. to be applied to the vertical plates of the cathode ray tube. A linear time base generator provides deflecting voltage for the horizontal pair, thus giving the decay trace in db./sec. Four values of the time for a single horizontal traverse of the spot-1, 3, 5 and 7 seconds—are provided to handle reverberation times of rooms from small studios to large auditoria. The recording speed is approximately 550 db./sec. The decay curve can be visualised by using a persistance vision screen.
Similar content being viewed by others
References
E. C. Wente and E. H. BedellJ. A. S. A., 1930,1, 422.
R. F. Norris and C. A. AndreeIbid.,, 1930,1, 366.
V. O. KnudsenIbid. 1933,5, 112.
F. V. HuntIbid.,, 1933,5, 127.
—Ibid,, 1936,8, 34.
W. M. HallIbid.,, 1939,10, 302.
H. J. SabineElectronics, 1937,10, 30 (March).
E. C. Wente, E. H. Bedell and K. T. SwartzelJ. A. S. A., 1934, 6, 121.
Ralph E. Meager and E. P. BentleyR. S. I., 1939,10, 336.
Author information
Authors and Affiliations
Additional information
(Communicated by Sir C. V. Raman)
Rights and permissions
About this article
Cite this article
Bhatt, N.B., Subrahmanyam, D.L. An electronic reverberation recorder. Proc. Indian Acad. Sci. (Math. Sci.) 25, 70–74 (1947). https://doi.org/10.1007/BF03172548
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF03172548