How do I get the Hearing Aid Assistance Tax credit?

There is not a Hearing Aid Assistance Tax credit available on a 2016 tax return.

You may be referring to propsal introduced in the Congress during 2017 which has not been enacted as of this date.

See https://www.congress.gov/bill/115th-congress/senate-bill/48

Is this a state credit perhaps?

I checked, and don't see one.

A similar Federal bill was considered back in 2014, but never passed.

@davidsstubbs 2
"Just purchased"  IF such a bill becomes law in 2017, you would claim it on your 2017 return that you file in early 2018.

Sorry but no.  The proposed law (if it passes and passes as written) says:

c) Effective date.—The amendments made by this section shall apply to taxable years beginning after December 31, 2017.

So it will not be retroactive to the 2017 tax year.

Thanks to all responders. I saw the 2014 bill (I guess), but didn't notice it wasn't passed. And the chances that this Congress will pass it seem low.

But you can still claim them as a Medical itemized deduction.