The problem may be that the hearing aid(s) aren't configured for the
person.  Nobody loses their hearing at the same rate or the same
frequency loss as anyone else.  A proper hearing aid allows for
configuration for the specific person's hearing.

Cheap off the shelf "hearing aids" are mere amplifiers, and all
a mere amplifier will do is amplify the sounds, which won't deal
with lousy high frequency response (by the time it's loud enough
up there, a straight amplifier will supply way too loud low frequency
sounds), or the loss of dynamic range in the ear.

An external box, which is what hearing aids looked like back before
transistors made for small units, is still a hearing aid.  The only
advantage is if it does pack more circuitry in there, but chances
are very good that it's just a cheap amplifier.

The one thing that may help is to get the signal pickup closer to
the sound source, so one doesn't have to turn up the volume control
to hear someone across the room; the problem then is that it also
amplifies every sound, and the ratio is the same.  A directional
microphone, or one placed closer to the person speaking, will
get a better signal without picking up the junk.  Some/many hearing
aids have external inputs, though I'm not sure there is a standard,
to allow for external microphones.  That's always a better choice
since it incorporates the hearing aid's frequency shaping and any
AGC that was configured for the specific user.

The same when watching tv.  Bringing the signal direct from the
tv set via a headphone extension or even a microphone placed close
to the tv set's speaker, will get the user closer to that sound
source without having to turn up the volume and hear the
frogs outside as loud as the desired sound.  If the current
hearing aids have external microphone jacks, then that's the
way to go.

Many/most hearing aids, at least real prescription ones, have
an induction loop inside, to allow the aids to be used with
telephones.  So that's another way of coupling a signal into
the hearing aid, a microphone feeding a small amplifier that
feeds an inductive coupler placed next to the hearing aid(s).
Again, that includes the frequency shaping of the hearing
aid in the signal chain, unlike an amplifier feeding headphones.

So the person should be checking to make sure the hearing
aid(s) are still useful to them and properly adjusted.  The
hearing aid store is bound to have useful accessories, including
pre-made inductive loops to get sound into the hearing aids (assuming
they have the "telephone pickups").

There may be a local store that sells products for those with
hearing loss, be it a standalone store or one that generally
supplies items to the handicapped.  There may also be organizations
that help those with hearing loss, that may offer such items
on a cost basis or point to local resources.

     Michael