Each of the two manufacturers supplied one pair of behind-the-ear hearing devices for testing. The control group had the volume turned off and the test group had the volume turned on fully. All units were subjected to a series of 21 exposures of 90kV(p) and 15 mA, resulting in cumulative doses of 5.465 to 5.516 R. All devices were analyzed for any changes that resulted from radiation exposure. Both vendors reported that no changes had occurred. For legal reasons, however, one vendor suggested that it would be best to remove the hearing device before exposure to radiation. Such prudent action might prevent the occurrence of a very unusual accident. A third company that conducted a similar experiment on its own units indicated that no changes had occurred. The company's testing facility also suggested that a vendor should not give any warranty and recommended the hearing aid device be removed before radiographic examination.