Pierre Henry sound effect & Shortwave radio [RADIO]

In 1975, I saw a ballet on tv, "Messe Pour le Temps Present" by Maurice Béjart, on music by Pierre Henry. I later found the album and still play it frequently. Just yesterday I stumbled upon the likely source of one of the sound effects in the score, while searching for amateur radio transmissions on short wave radio. Slowly tuning past a frequency using SSB, I hear that same sound. I document it here, using snippets of Pierre Henry's sound track and footage from Youtube of a ballet interpretation, by Hervé Robbe, recorded 09/01/2016 at the CNDC of Angers.
(https://www.youtube.com/watch?v=ndzbTfcMY_o)





Youtube version: https://www.youtube.com/watch?v=Y-yKdM6HiQs