Pretty sure that depends entirely on the individual. Since being deaf (or blind for that matter) isn’t as binary as it appears there are various degrees of hearing impairment. Perhaps one person is completely deaf, while another is still able to perceive certain frequencies, and yet another just needs it to be really fucking loud but if it is they hear just fine.

From my personal experience with a nearly deaf acquaintance they are using a special kind of hearing aid they can tie into their devices via Bluetooth. So they have the sound sent directly to the device specifically configured to allow them to hear.