I had never noticed this until today, but then again, I've been away from the TLM (save for a single Mass in December while my late mother was in hospital) for several months due to my mother's illness --- she has now passed away --- and maybe it was that way all along.  

The priest read the passage from John in a voice that, to me anyway, seemed just a little louder than the other parts of the Mass.  I could clearly hear him.  Was this my imagination, or is there something in the rubrics (or even common custom) that mandates or provides for this?

Good to get back to Mass, but kind of sad that it took my mother being taken out of her misery by death to make that happen.  I am laying her to rest tomorrow.  Requiescat in pace.