Results of standard audiometry and tympanometry were compared with the Welch Allyn 'Audioscope' and 'Microtymp', in the diagnosis of secretory otitis media, in 100 children. Standard pure tone audiometry had a specificity of 92 per cent and sensitivity of 51.6 per cent. The Welch Allyn 'Audioscope' a specificity of 84.2 per cent and sensivity of 57.5 per cent; standard tympanometry a specificity of 71 per cent and sensitivity of 88 per cent; the Welch Allyn 'Microtymp' a specificity of 63 per cent and sensitivity of 90 per cent. In view of cost, portability, and speed of testing the Welch Allyn instruments would be particularly suitable for community screening. Pure tone audiometry with a pass threshold of 25 dB, at 2 and 4 kHz is a poor indicator of effusion.