Biomedical subjects
Publications and source records attributed to M S Shipton.
A number of new British Standards have been published which affect users of audiometers and audiometric calibration equipment. These are identical to their international counterparts, giving us agreed values for thresholds of hearing by both air and bone conduction. This article draws attention to the important changes that have taken place and looks forward to likely future changes.
The diaphragm of a condenser microphone is exceedingly fragile and, in normal use, is covered by a protective grid. However, when the microphone is incorporated into the IEC 303 reference coupler for the calibration of audiometers or audiometric earphones, the Standard demands that the diaphragm be left exposed. Nevertheless, in order to avoid inadvertent mechanical damage, some users leave a protective grid on the microphone. The effects of two particular grids have been investigated and the magnitude of the resulting errors is indicated.