Mark and everyone,
Although I am not a tinnitus researcher, I have had lots of experience with patients with tinnitus in the audiology clinic. Generally, we try to avoid the confusion of tinnitus with testing tones by using pulsed and/or warbled tones. As you point out, this doesn’t always work out perfectly.
It has been my experience that dips in the audiogram are indeed frequently accompanied by tinnitus. having measuring hearing at the VA, this connection might be limited to hearing loss that is noise-induced. The two most common explanations I have heard for this are 1) damage to the auditory system at the site of the hearing loss underlies both the threshold elevation and improper firing by damaged nerves, and 2) tinnitus that exists in the region of the dip is not masked out by external stimulation because the external sounds are less audible; thus rendering tinnitus more noticeable. This latter explanation accounts for the relief from tinnitus experienced by many people who use hearing aids. Specifically, tinnitus isn’t “cured,” but it is masked out by the amplified input, and then the tinnitus returns after the hearing aid is removed.
Returning to the point of tinnitus without apparent hearing loss, I have found that salt intake and stress level are two (among many) contributing factors to and my own tinnitus, and I don’t have hearing loss. The dependence of OHCs on metabolic factors underscores this connection, which seems anecdotally to be exacerbated in patients with Ménière’s.
Matt