OK, well that is considered the first important step. She could have hearing loss, which could be "fixed" by a hearing aid. You should get an audiology exam. She is 8 (I think you said), so she is definitely old enough to get an accurate exam. Don't be so sure the 40% loss resolved- at age 3, you really can't get a good hearing test.
I have mentioned before that my son has a 70 dB loss in his right ear (85 dB is "Helen Keller deaf), and that was completely missed 3 years in a row at the pediatrician's. And I'm a doctor.