I ended up fixing both. After I got the rubber (did a crappy job), I put it on & she said it was a little better, but still did it. So, I got out the drill & was a bit more cautious. After that, she said it wasn't quite like no case at all, but a LOT better. Didn't make noise with every little movement I made or sound like I was in a tunnel.
Word to the wise, at least on my red bumper, the plastic is actually white. Make sure you've got some nail polish around. My girlfriend had a good shade with a fine applicator for fancy designs (she went to beauty school). You'll see the white below. I chose to only paint what would show. I also touched up a couple chips in the inside. Might not bode well for the longevity of the case though.
Here's the botched rubber cut. I used a leather punch & then scissors to get the clingy bits.
Though I didn't quite get the hole even with the others, I don't think the finished product looks bad. I over compensated on the plastic because my holes were originally a bit too far the other way on the rubber, so I bored it out a little with the drill bit. I figure at least this way, the rubber isn't smooshed between the phone & the bumper.
In hindsight, cutting the rubber from their hole location to where it should be probably would've had the same effect as the tunnel shown in preach's previous post, but this way, I know the hole has more direct access to the mic.
Sent from my Note 4