Performance of neonatal and infant hearing screens: sensitivity and specificity.

The terms 'sensitivity' and 'specificity' are defined and some of the factors that determine their values are discussed in the context of screening for permanent childhood hearing loss. There is a need to distinguish between the values observed in 'simple experiments' and those that may be obtained under more realistic 'field' conditions. It is not feasible to give a meta-analytic overview of published data because of the variety of methods and objectives used in those studies published in the literature. However, a qualitative synthesis of the data is possible. This suggests that most proposed neonatal hearing screening tests, when implemented in accordance with a programme of quality assurance, can be reasonably accurate at a modest cost. However, the optimal combination of tests and test parameters for given populations has not yet been fully researched. The infant distraction test screen has a lower sensitivity than neonatal hearing screening tests, particularly for moderate impairments, accompanied by a fairly low specificity.