A researcher involved in the review said that many patients have been emailing to complain of hearing issues after COVID-19, underscoring the "urgent need" for diagnostic study. (BSIP/UIG Via Getty Images)Researchers say there is mounting evidence suggesting that hearing loss and other auditory issues are strongly associated with COVID-19 infection, according to a systematic review.At least one clinical study is ongoing, but using data from 24 concluded studies that mostly relied on self-reported questionnaires or medical records, researchers from the University of Manchester and NIHR Manchester Biomedical Researcher Center found that up to 7.6% of COVID-19 patients suffered from hearing loss, 14.8% complained of tinnitus and 7.2% reported.