Summary: This paper covers the use of a tone track for automatic control of music and effects background in rerecording.
During World War II those of us who were left at the studios were exceedingly busy working on government training films of a wide variety. It was necessary that these films be finished as quickly as possible as they were urgently needed for training the large number of men being taken into the military and naval services. Some of these films had no music or effects background behind the narration, but many of them had. This meant that the mixers must use footage counters, screen cues, or other means to indicate where the dialogue or narration started and stopped in order to fade or bring the background volume up in the proper places. Watching a footage counter or screen cues for long periods of time is very tedious and those of you who have experienced this know that it is very fatiguing.
Our first attempt to avoid this process was to use the RCA so-called "up-and-downer." This worked quite satisfactorily, but, when the narrator stopped for breath or made a slight pause, the background would rise in volume which was not desirable during these brief intervals. The timing constants of the rectifier and variable gain amplifier were adjusted to avoid this to a degree, but in doing so the fade and increase in volume time were not satisfactory.
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