Why are bass tones relaxing?

I'm also talking out of my ass, but it could be because on a subconscious level it reminds us of being in the womb when all sounds were perceived through basically a low pass filter.

Completely talking out of my ass, but bass is generally much lower frequency and higher frequencies are more energetic.

Same with light: infrared we perceive as just heat, then as frequency increases it becomes visible red, and as you go up you get blue and violet and UV, which starts burning your skin very easily.

We know blue light affects sleep and reds are much more pleasing at night, so logically I'd expect something similar to be valid for sound as well. And we use ultrasound to clean stuff just like we use UV to sterilize stuff.

They mimic the voices coming out of relaxed chests and throats.

But extremely low bass isn’t relaxing. It mimics the sound of very large predators.

I think that whether or not a person would be comforted by bassy sounds would depend on their upbringing, specifically if and how they were socialized to enjoy music.

IMO because bassy sounds are more likely to come from large or powerful processes in nature, like explosions, falling rocks, thunder (caused by lightning which is dangerous if outdoors or in a weak structure), and very large predators, I imagine that people not socialized under the Western music tradition (or any other which uses long bassy sounds) might find bassy sounds to be distressing.

I'm not a musicologist, but they would probably be the person or author of the book to consult.

You got a big speaker right?

This black man has a captivating soothing smooth deep voice, I've been binge-watching his videos.