Peter Pichler accompanied Hitchcock's thriller from 1963 live with his Mixturtrautonium for the concert series "ReiheM" in Cologne.
Hitchcock did not put any usual film score to this thriller. He used a more "abstract approach", as he said. Natural bird sounds didn't seem to convey the terrifying atmosphere he found and searched very long for the fitting sounds. In the end he found Oskar Sala in Berlin, who put electronic bird-sounds and effects to his film. The only natural bird sounds you hear in the first scenes of the film in the bird-shop. The rest is made with the Trautonium.
One experiences these sounds as very threatening and yet they are so strange that one cannot really determine with absolute certainty, if these sounds might perhaps not stem from really angry, crazy birds in the end. …. who knows…. :-)
Kino 813 in der Brücke
further information you can find on the Homepage of "ReiheM"