In potentially-dangerous-animal country (e.g. grizzly bears, mountain lions, etc), it could be a safety mechanism...I was told repeatedly you need to make some kind of distinctive noise regularly so they won't get startled by you rounding a bend.

those people, i've encountered them too, don't give a shit about anything let alone being safe around wildlife. If prey distress calls could be confused with music they'd be blaring that just as well.

That's what "bear bells" are for...in bear country.

Mountain lions are avoidant at all times unless it's a mother with cubs and even then they'll let you know well in advance.

Otherwise, just normal conversation, your smell with even a light breeze, and the vibrations on-trail will alert all animals to your presence.

In other words, the "trail music" theory is bullshit. They just want to listen to their music.

These people probably don't do it for this reason, but you're correct, at least when it comes to bears.

lol.

that's like harley riders with unmuffled motors "for safety".

On the other hand, I remember being in japan and watching some construction vehicles in tokyo. They were surprisingly quiet. After a while I realized what it was - in the united states all construction vehicles have these annoying "beep-beep-beep" sounds while they're working (for safety).

I wonder if one day they can play those only when someone walks nearby or play in some technologically quieter way.

Huh? I’ve never met anyone in the backcountry that played music to keep predators away. Even when forced to hike at dusk, the primary risk is quietly stumbling on a predator out stalking, or worse, a predator’s offspring. At most you clap every so often, maybe talk/sing to yourself, or dangle some stuff from your pack at higher risk times. Animals will do the hard work of avoiding you When you’re nearby, but its quite unnecessary to notify everything with in a 1km radius of your presence.

This is my reason for blasting music from my bicycle. Feels less rude than clicking a bell at the pedestrians and somewhat more effective at attracting attention.