by Barry Keate

Have you ever experienced a sudden, brief ringing sound in one ear that seems quite loud then tapers out over a short period of time? Many people have and for a lot of them, it can be very frightening. One might worry, “Is this the start of permanent tinnitus? Is my existing tinnitus getting worse?”

It turns out this is a very common experience. It usually does not mean permanent tinnitus is beginning or is it getting worse. For the great majority of people who experience this, there are no lasting effects. This sudden brief tinnitus usually dissipates within a minute or two and does not repeat in the near term.

This phenomenon has not been studied until recently and very little was known about it. Now a multicenter study from Israel, Canada and the US sheds light on what has been a little understood sensation.[1]

The researchers describe these episodes as a sudden perception of a tone in one ear that fades away within seconds and seems to have no definite trigger. It can sometimes be associated with a feeling of fullness, pressure, blocking or hearing loss of the same ear. Once it begins, it remains at a constant loudness for several seconds then wanes until it is no longer perceived. All the while, the quality of the tinnitus otherwise remains unchanged. The entire event typically lasts less than a minute with no permanent change in hearing. Such an event is termed Sudden, Brief, Unilateral, Tapering Tinnitus (SBUTT).

Study Methods

The paper encompassed two clinical studies. Study I was not focused strictly on SBUTTs. Its main purpose was to determine the effect of brief but very intense jaw, neck and extremity muscle contractions (somatic testing) on the auditory experience of subjects who were sitting in a room with low ambient noise.

We have previously published an article on Somatic Tinnitus describing the muscular and auditory processes that lead to this type of tinnitus.

Before they were asked to make the muscle contractions, an interview was conducted and one of the questions asked was, “Do you ever have a brief ringing in one ear, lasting a minute or less?”

Study II was restricted to volunteers who all responded they had experienced SBUTTs previously. They were asked to keep a log of the occurrences for four months.

Study Results

Study I was conducted for somatic testing of subject’s hearing. Twenty percent had existing tinnitus. Of all subjects, 76% could recall having at least one SBUTT at some time in their lives and 24% had no recollection of ever having one. They occurred in equal proportions in men and women.

Of the subjects with existing tinnitus, 75% had SBUTTs. Of those with no ongoing tinnitus, 78% had SBUTTs.

Study II was conducted exclusively on subjects who had experienced SBUTTs in the past. Very similar to Study I, 20% of participants had existing tinnitus. The existing tinnitus subjects had more SBUTTs than the non-tinnitus subjects, 8 instances compared to 4 instances over a 4-month period.

SBUTTs were always heard in one ear only. Right ear occurrences were about twice as common as left ear in a ratio of 65% to 35%. Some subjects experienced fullness or hearing loss, always in the same ear as the SBUTT.

Study Discussion

The initial survey found that approximately 76% of subjects experience SBUTTs. Still unanswered is the prevalence in specific populations. The prevalence is unknown in those with profound hearing loss, tinnitus in one ear only, or those suffering from Temporomandibular Joint (TMJ) dysfunction or whiplash.

The rate of occurrence of SBUTTs varied from less than one per year up to 130 per year. The study found that 3 of 4 subjects with the highest number of SBUTTs also had chronic tinnitus. This suggests that a high rate of SBUTTs may be a risk factor for developing chronic tinnitus.

The finding that SBUTTs occur more commonly on the right than the left favors the possibility that they are related to the somatosensory system because, on average, more than 90% of people are right-handed. The somatosensory system of the dominant side would be expected to be more forcefully activate than the non-dominant side