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.

Bear bells have been shown to not be effective.