It's not just you.

Like Chinese, with which it has some historical connection, Vietnamese is a tonal language. And, of course, so is Thai.

It's the sing-song sound of those tones which make these languages unattractive to me, along with the high-pitched voices. Listening to it day after day is a real trial.

I wish they'd drop down an octave.

Vietnamese and Thai sound totally different to me.

BTW, no "high-pitched squealing" from me, whether I'm upright or horizontal!