Last night I watched The Mighty Peking Man for the first (and probably last) time. It's a 1977 Cantonese King Kong ripoff, made purely "to capitalize on the craze surrounding the 1976 remake of King Kong."[Wikipedia]
The Peking Man himself (a.k.a. Xingxing Wang, a.k.a. Utam) is a ten-story-tall gorilla from the jungles of the Himalayas. But rather than doing King Kong grunts or Tarzan yells, he makes this awful nails-on-a-blackboard screeching noise.
You can hear the screech for yourself around 2:11 in this clip.
When I heard this, my reaction was, "Why is a giant ape making the Godzilla noise?" (An example from Godzilla versus Hedorah (1971) is at 3:17 in this clip. Very similar, yes? And I'm sure the top answer will provide tons more examples of the same sound effect.)
Now, it's not literally the same sound effect AFAIK; we're not talking Wilhelm scream here. But it seems like many Japanese and Cantonese movies of the 1960s–1980s have a particular archetype for "what big monsters sound like" — namely, they screech. Whereas in American big-monster movies, the big guys make much more guttural, animalistic vocalizations, like the dinosaurs in Jurassic Park or King Kong (2005) (or Kong's noises in King Kong (1933), for that matter).
Why is this? Are there any academic studies on the subject? What's the historical timeline of big monster screeches — in particular, did it all start with Godzilla (1954), whose noise was famously made by a resined glove rubbing the strings of a double bass? But Godzilla's 1954 roar actually isn't as screechy as kaiju noises became two decades later; so what triggered the escalation in screechiness?