Also make sure the blade assembly ring on the bottom of the jar is snug and the gasket isn’t pinched or flipped; a flattened gasket is a cheap swap and can stop rattling and leaks. Start on low with some liquid in first then ramp up and and keep the load balanced (don’t run ice or frozen fruit dry) to reduce cavitation and vibration. A quick test with water in the jar helps: if it’s still loud it’s likely mechanical, if it smooths out it was the load and technique.
I wear cheap earbuds, point at groceries, say 'deadline,' and walk. For what it's worth, taking a few minutes to practice this in a calm setting usually helps it stick.
