The contribution of social noise to tinnitus in young people - a preliminary report.
In our study of the Hearing in Young Adults (HIYA) aged 18-25 years, there appeared to be little effect of social noise on hearing thresholds (Smith et al. 1998). There was however, a threefold increase in the reports of tinnitus in those subjects with significant social noise exposure (>/=97 dB NIL). No other abnormality was found of hearing function for those who were exposed to the most social noise. In an attempt to investigate this further we invited a sub-sample of those tested in the earlier phase of the study, to conduct further examinations of their hearing function. The three groups eventually consisted of those in the most social noise group who reported tinnitus (n=15) and those who did not (n=15), plus a group of people who had no social noise exposure but who reported tinnitus (n=8). All the groups were retested for their hearing thresholds, using standard audiometry and also the Audioscan technique to look for notches in the audiogram. Speech tests were carried out using an adaptive FAAF test. Transient-evoked oto-acoustic emissions were measured and also suppressed with a contralateral broad-band noise. Some evidence has been found to suggest that those young people who reported tinnitus are affected by social noise exposure, in terms of pure tone thresholds, speech tests, oto-acoustic emissions and reported hearing problems. Lessons can be drawn from our attempt to follow up this interesting population. First, the population is highly mobile and follow-up is difficult. Second, the presumed noise exposure was often not appropriate because even after a year it was possible for several individuals with insignificant social noise to move into the group with significant social noise exposure. Third, there is a need for a larger multi-centre study to look at the effect of social noise in more detail using a common protocol. The results of our study will be very useful in calculating the numbers needed in such a multi-centre study.
Davis
A. C.
AC
MRC Institute of Hearing Research, University Park, Nottingham, NG7 2RD, UK.
Lovell
E. A.
EA
Smith
P. A.
PA
Ferguson
M. A.
MA