I have a safety base 'short piece' of early (I think predating Phonofilm)
sound film. The track's a density type & is about .25" wide. My hunch is
that it's long enough to yield a very shot loop that would at least enable
analysis of the characteristics i.e. a signal to noise ratio that's not
positive.

Whether you'd like to see it merely out of curiosity, or better yet, ID it,
then then I'll be pleased to a scan of one frame of it.

The picture is a left side profile shot (yeah, I know, it's politically
incorrect) of a woman speaking into a horn, whose narrow end seems to be
physically connected to the track: shades of Tex Avery....

Bill Seery thinks that it's not by Lauste. Knowing what it isn't is just as
important as what it is.

Thanks,
Art Shifrin