Ynaig, you told us you once heard perfectly clearly (after some healing work) albeit just for a very short time. Since you know it *is* possible (experience being the best test)you must also intuit at some level that there is something 'blocking' your hearing--or you wouldn't be asking for help with understanding the Louise Hay. Surely the whole book can't be "correct" but the one statement that addresses your situation be "incorrect", while being "correct" for others you see. Do you see how humorous that it:-) In my experience, much as I find it uncomfortable -I just went through something with my neck that didn't sound right, but when I looked further I saw it was the thyroid more than the neck per se- anyway: I find it's always "me" that is blocking my oneness with joy, and no-lack.
Personally, I find forgiveness ongoingly,( esp. of self getting in the way of Self), to be very expansive.