This question might be too subjective to answer, but for those that have used Paris Walks, how easy was it to hear the tour guide? As background, I wear hearing aids and while they mainly boost conversations to an audible level for me, they can have a difficult time picking out a single person's voice in a (potentially noisy) outdoor environment. I did contact Paris Walks and asked if they used any sort of amplification or head sets and I was told that they don't.
I suppose a related question is how large have the walking groups typically been? If they're small enough (less than 5?), I think I'd be fine...