Hearing test showed mild loss in right ear. also pain and titinitus. ent doctor dismissive and ordered no further testing. is it something sinister?

Get 2d opinion: hearing loss may occur as one ages, but my experience is that pain and tinnitus suggest the presence of unresolved infection or toxin in either the ear or TM joint.

Second opinion: In many cases, seeking a second opinion is not only warranted, but necessary. Unless your disease is life threatening and requires emergency care, it is never a bad idea to seek a second opinion, because the cause for your condition is not found, but the symptoms continue. Hope it helps.