The simply-named Oi, made by Australian cycling gear company Knog, is a bike bell for people who don't like bike bells. Such folks may be particularly keen on the latest model, the Oi Prima, as it's sleeker, slinkier and better-functioning than ever before.
AirZound baby.
I do have a bell for first warning too.
In reality I ride with the assumption that pedestrians don’t hear me or see me and maneuver safely around them. So I rarely use sound alerts. The AirZound is mostly for cars.