From "Audiologists' Desk Reference, Volume II" (1998)
Transient Spontaneous Tinnitus (TST)
- An apparently normal period of tinnitus, usually a high-frquency (>1000 Hz) ringing, lasting only a few seconds.
- Sometimes further defined as transient high-frequency spontaneous tinnitus (THFST)
- May rise in subjective intensity, and then fade away.
- Only one ear is affected at any time, although both ears can be affected over time.
- The tinnitus is often foreshadowed by a sensation of fullness in the same ear and very slight dulling of hearing sharpness.
- TST may occur many times per week or infrequently as several times per year.
- May be related to oscillation secondary to instability in the nonlinear electromechanical properties of the outer hair cells, with a rapid stabilization with a dampening of oscillation (LePage, 1995).
- May occur when one is tired and especially noticed in a quiet environment.
Vernon J, Schleuning A, Odell L, Hughes F. A tinnitus clinic. Ear, Nose, Throat J, April 1978:58-71; LePage EL. A model for cochlear origin of subjective tinnitus: Excitatory drift in the operating point of inner hair cells. In Vernon JA, Moller AR (eds). Mechanism of tinnitus. Needham MA: Allyn & Bacon, pp. 115-147, 1995
From "A model for cochlear origin of subjective tinnitus: Excitatory drift in the operating point of inner hair cells" (1995)
Page 119 comments a case of a 47 male tinnitus sufferer, who had a background of in relevant disciplines such as "mathematics, physics, and engineering, plus twenty years researching auditory physiology", plus "32 years experience tuning pianos":
- TST has occurred since early teens; long before any manifestation of continuous tinnitus, it occurred only with a single pitch corresponding to a frequency in the range never below 1 kHz and seldom above 4 k Hz.
- The incidence has been episodic, maybe twenty times per week during periods of frequent music exposure or great tiredness, to less than once per week at other times: total number of occasions estimated to be many thousands.
- Only rarely is TST associated with a specific incidence of overexposure.
It doesn't associate these episodes with anything. They just seem to happen at random. The whole book chapter is at
http://www.oaericle.com.au/pdfs/LePage_TinnitusBookChapter.pdf It's not aimed at the general public, thus, no clear takeaway points.
I think that a common worry in Tinnitus sufferers is that TST (aka fleeting tinnitus) may indicate that you are getting worse. I have never read such a thing in literature or from a patient testimony. As Markku said, it doesn't seem to have clinical significance.
Following some references I found that before the 70's, the ear was considered a passive linear mechanical sensor (where response is proportional to the cause), and it took a decade to find out that the ear is non-linear "and that this property is related to active process in the living organ".