They do say it can be reduced depending on how you use it.
Finally, here's a snippet of an Amazon review:
> I just played 7 hours of continous music with the noise canceling activated at high volumes and there's still almost 30 percent battery avaliable.
And another:
> I used the earbuds for 8 hours between ANC & transparency mode, ... Considering how often I use the earbuds after 8-10 hrs per day and 4-5 days of use from a full charge, the battery life is still 2 lights remaining.
One review does state lower life with ANC:
> But, a full charge only lasts me 6 hrs with anc on auto and volume at 50% or less.
A few reviews talk about even lower battery life, but given Wirecutter's tests and the preponderance of those who get long battery lifes, I'll assume the exceptions are defective products.
In any case, is ANC even relevant for hearing aids? I would have thought ANC would be a hindrance.
(In general, several reviews refer to using it continuously for their work shift).
The one thing that may not be particularly good is the mic.
Edit: Here is someone who tested with ANC on. They got 7hr 55 min:
I'd say 4-6-8 is low-average-high duration for the standard form factor and ANC will reduce the duration by 25-30%
10 hours is exceptionally high, i don't think i even seen that claim
But year, they don't even have ANC, they are just a good pair of buds, the 10h claim is good.
Pro tip:
You know that a pair of buds is good if they offer Multipoint. It is such a hard feature to find in the mid and low end market