Pure tone audiometry is the most common method of screening for hearing loss. The test itself is straightforward and the equipment readily available, so it forms part of the hearing conservation programmes of many industries. Whilst the test itself is straightforward, because of individual variability in response, interpretation of the results may be difficult. There has therefore been considerable debate on the role of audiometry in hearing conservation. The last official publication dealing with audiometry was a Health and Safety Executive discussion document 'Audiometry in Industry' published in 1978: no current recommendations are available. This article is a critical review of the advice given in that document, which aims to clarify the role that audiometry may play in the conservation of hearing. It was concluded that audiometry in the individual may perform poorly in strict cost benefit terms when used serially to detect a deterioration in hearing of an individual, but as the only form of biological monitoring it should be available to all employees who are advised to wear hearing protection at work. A distinction between audiometry in the individual and group audiometry is then made: the analysis of the hearing of a group may be useful in assessing risk to hearing. Graphical methods of analysis are shown, and more formal methods of statistical analysis discussed.