Cause of hearing loss

Is it possible to know the cause of hearing loss from an audiogram? I’ve never had that discussion with an audiologist and I’m curious as to what may have caused it.

I’m aware that certain childhood diseases as well as some antibiotics in 50’s and 60’s could cause hearing problems. I’ll give a little background here. I’m currently 72 and doing well with Phonak Audeo P90L’s. When I entered the military in 1967 my hearing was nearly poor enough to prevent me from serving. I spent time in a combat zone in close proximity to artillery and frequent firing of small weapons. In those years there was little(no) hearing protection provided to service members. I have no record of a hearing test at discharge. Later in life I worked in a factory setting for 10 years or so with constant machine noise. In the 90’s I was denied acceptance for a specific training course in the Army Reserves due to hearing loss.

I would imagine that the combination of my life circumstances lead to where my hearing profile is at present but I’m curious why the poor hearing when I entered the military at a young age. Could there be clues in my present audiogram?

Some etiologies are pretty obvious from the audiometric configuration (cookie-bite, reverse slope, otosclerosis) but many are not. You could have a genetic panel done, I suppose? I hear that in the states you can just pay for whatever medical procedures you want.

Congential hearing loss is hugely genetic. I believe, when not assossicated with other syndromes, it often comes down to one of two recessive genes that you can be heterozygous or homozygous for. In well-babies without a genetic component, I believe the next most common cause is congenital cytomegalovirus, which I believe is also the most common infectious cause of birth defects generally but which is weirdly unknown. [The typical route of infection is that an older toddler picks it up and passes it to the pregnant mother through saliva and then it passes through the placental barrier to the fetus. Infection can be reduced by not sharing food with your toddlers, avoiding saliva transfer generally, hand washing. So, if you know anyone who is pregnant or planning to get pregnant let them know; I don’t know why doctors don’t talk about this.] After genetics and cCMV, in well-babies I believe next up is idiopathic hypoplastic auditory nerve. Lots of possible risk factors in NICU babies (e.g. forced oxygen, chemotheraputrics, glucocorticoids).

There are some other rare genes that cause progressive loss later in life (cookie-bite confuguration being one). A child with a strong history of ear infection, tubes, eardrum perforation may also present with minor conductive hearing losses later in life. And then childhood illnesses that were once common and now less so can be associated with hearing loss (e.g. measles, rubella, scarlet fever).

Non-genetic and non-noise causes in adults include autoimmune and cardio issues. However, there is noise and then there is NOISE. Long-term exposure to, say, factory noise will cause what we generally think of when we think of “noise-related” hearing loss and tends to be sloping high frequency or notched high frequency, but artillary fire can cause actual mechanical sheering damage within the cochlea and may look quite different in terms of audiometric configuration.

PSA: Smoking also increases your risk for noise-related hearing loss and hearing loss generally. I mean, it’s 2023, who smokes anymore? But boy it was cool when I was younger and what a beast of a habit for some people to kick.