Using a whistle

[MartianDestiny]

I have NEVER heard a cyclist with a whistle and I would NEVER associate such a noise with one.

Use a bell or your voice. Both are the only things likely to be conditioned into another trail user as a polite cyclist wishing to pass. NEITHER is universally understood by all trail users, but better than nothing I suppose.

It is still always on you, the cyclist, to pass safely without hitting another trail user regardless of how oblivious they are being.

[shootingstar]

I have NEVER heard a cyclist with a whistle and I would NEVER associate such a noise with one.

Use a bell or your voice. Both are the only things likely to be conditioned into another trail user as a polite cyclist wishing to pass. NEITHER is universally understood by all trail users, but better than nothing I suppose.

It is still always on you, the cyclist, to pass safely without hitting another trail user regardless of how oblivious they are being.

Yes, many people wouldn't associate a whistle with cyclist.
My bell is not working completely. Anyway....

When I see a child ahead potentially in my way, I call out, pleasantly: "Excuse me!" Then when I get closer to child, (slowing down) especially if they are young and on their own little bike, I say loud enough or yell cheerfully: " Beep-beep. Beep-beep 'Excuse me." Rather than ring my bell, I actually say to young children: "Beep-beep, beep-beep".

Most young children have responded well to this. And it doesn't startle them and you haven't been inappropriate to the child in front of the parent nearby.

It comes from playing with young children, right? It works for me.

For anyone older, I do use my voice and yell/say loudly on your left or 'excuse me'/similar. I try to thank them when I pass them.

Sometimes you do have to be rude/loud..especially if one suspects they might not understand English. At least you got their attention.

Be realistic. You do have to slow down a tad when approaching people on a tight path from behind them.