Influence of age, type of audiometry and child's concentration on hearing thresholds.

Surprisingly little evidence is available in children between the ages of 3 and 7 years on the effect on hearing thresholds of the method of audiometry and of the developmental ability to concentrate and to respond. The Trial of Alternative Regimens in Glue Ear Treatment (TARGET) is a large, national, multi-centre trial of surgical intervention in children with otitis media with effusion (OME) that offers an opportunity to study these effects. Of 1517 children, aged between 3.25 and 6.75 years, reaching the selection stage, 4.5% were unable to give reliable air-conduction thresholds. A further 3% (i.e. 7.5% in all) could not give reliable bone-conduction thresholds. This inability was greatest in the youngest children. During air-conduction testing, a significantly greater proportion (p <0.005) of children were recorded as having only 'fair' or 'poor' concentration on conventional audiometry than with play audiometry. On the other hand, the magnitude of the effect of poor concentration, as rated 'fair/poor' versus 'good', was slightly greater on play as opposed to conventional audiometry (+5 dB versus +3 dB). Although statistically significant, the age of the child had only a very small effect on the air- or bone-conduction thresholds, once the type of audiometry, concentration and the presence of OME had been controlled for. It is concluded that adequately informative thresholds are usually obtainable by conventional audiometry in this age group, even if the concentration is recorded as 'fair' or 'poor'. However, when conventional audiometry is not feasible, play audiometry should be attempted in the 3-5-year-old age group.