THE SOUND OF BIRDS?

As a pre-teen I found Alfred Hitchcock's THE BIRDS  quite terrifying,  but had little thought of "why?".  Its script's mix of human  desire,  motivation, confrontation,  and fear (as well as bits of humor) shed little light on the bird attacks that remain as frightening today as they were in 1963.   While recently watching a pristine Blu-ray edition of the film I noticed a least  part of the reason for the film's success as a plausible horror. Musicians Remi Gassman and Oskar Sala are given credit for "Electronic Sound Production and Composition",  which in a film with essentially no music (with the exception of  children singing as birds slowly amass outside the school) becomes an important part of its sound design rather than score.  Most of what we hear,  especially during the final attack on the protagonists' house,  is noise produced by one of the first electronic instruments (invented around 1929 by Friedrich Trautwein),  the Mixtur-Trautonium,  the second,  expanded version (noise & envelope generators,   formant & bandpass filters, subharmonic oscillators) of the original instrument.  As a "musician" working with modular synths,  I've wondered how these sounds would be received if divorced from Hitchcock's powerful visuals. Would they have been perceived purely as noise or heard as  intense bird commotion (I'm pretty sure real bird sounds were mixed in)? I especially love that tonal cliches are avoided since there is no chromatic keyboard,  merely metal touch-plates (shades of Don Buchla) and register wire. I certainly give Hitchcock credit for being willing to use seldom heard old tech to create new sounds and ways of hearing.