I try to recommend to new parents to get a big room air purifier to clean the air where the baby sleeps but also to add a nice low bass noise (from the motor) that you can’t get from a white noise generator. Our filtrete has been running non-stop for 11 years (kind of crazy).
Definitely helps keep them asleep and non sensitive to sudden noises in town/city.
I think it's more an indication of higher expectations in child-rearing. If you're struggling daily for survival and 7/10 of your children will die before age 6 I don't think can afford to spend hours every day experimenting which method will get your child to fall asleep without crying.
Except children in traditional societies demonstrably cry less and are happier (both parents and children). Anybody who has spent time living in traditional societies vs living in the West see the differences - chiefly, the sheer anxiety that western children are introduced to from the first day they step foot in the world.
Doesn't surprise me that people in a society that values individual liberty develop more anxiety as they are expected to take responsibility for their own decisions,
as opposed to a society where traditional authority commands you exactly what to do and you'll obey or else.
Long term exposure to constant droning sounds could cause issues in language centers of the brain.
When we rely on sounds for kids, we stick to sounds that mimic the more random/non-droning sounds you encounter in nature. Birds chirping in a forest, evening crickets and frogs etc.
They may be citing a study that circulated recently about how white noise is the reason why we have an autism epidemic. I can't seem to find the study, though. But I do remember laughing.
Anecdotal but I used a noise machine that played brown noise because I was informed it mimics the sound of the baby’s womb. My daughter is extremely advanced in all areas of learning now at 5 years old. Her first word was hi at 4 months.
Definitely helps keep them asleep and non sensitive to sudden noises in town/city.