 untreated hearing loss. Sometimes there's noise exposure. Smokers are more common to have tinnitus than non-smokers, certain medications. So there's so many reasons. So when you come in, we do a full evaluation, full case history, so we can really get an idea that there is tinnitus, what part of the ear is causing it. We know that low frequency tinnitus might be a sign of heart problems. So we really try to identify and rule out harmful factors that could be causing it and focus on the treatment after we can rule out anything harmful.