my family doc, back in the day saw patients five days a week, at least, 1/2 day, I think on wed and sat. his phone rang thru to his house in off hours. and there was established coverage when he was not available. on the other hand, his son was a year ahead of me in HS and went to Rensselaer poly tech for engineering, absolutely refused to be a doc.
since your hearing is unlikely to be effected, your tinnitus is entirely different than the prev poster's, and mine. steth choice is really not an issue. check out a little on line, cardiac consult is recommended, and endo for thyroid issues.