Welcome to the forum Eric.
It's great to see that your tumor dimensions are provide with a resolution of 0.1 mm.
Sad to hear than your hearing has deteriorated. It looks like hearing and acoustic neuromas are not compatible. (I don't think people appreciate the benefits of binaural hearing until its (suddenly) lost.)
On a volume basis, your tumor has grown closer to double than triple over three years (2.2x).
Most tumors stop growing after five years from diagnosis.
If your concerned about having active treatment in 30 years time when you're health is not as good at 65 years old, there's a few things to keep in mind. Firstly, in 30 years time you would expect treatment options to be better than today, MRI guided focused ultrasound, robotic surgery, a pharmacological solution or something else completely different is likely to be developed over the next 30 years. Something that leaves you better after treatment than before. Secondly, one of the neurosurgeons that I spoke to said age was not a factor, unless your frail. Finally, your quality of life is likely to be better in the mean time.
Keep in touch regarding growth.