Objective: To assess the utility of noise cancelation earphones (NCE) in audiometric evaluations.
Design: Degree of noise reduction of Bose QuietComfort 15 NCE was assessed through probe-microphone measures and sound-field audiometry. Occlusion effects from NCE were assessed for potential effects on bone-conduction thresholds.
Study sample: Twenty participants were tested to determine average occlusion effect values during bone-conduction testing with and without NCE. Noise reduction values of the NCE were assessed on a single subject through probe-microphone measures and sound-field testing.
Results: NCE sufficiently reduced ambient noise to levels acceptable for air-conduction testing as well as for bone-conduction testing for most patients when adding minimal adjustment to acceptable levels as outlined by the ANSI S3.1-1999 standard. In addition, NCE did not create a clinically significant change in the occlusion effect for bone-conduction testing.
Conclusion: NCE placed over insert earphones provide a sound pressure level at the tympanic membrane that is below ANSI standards for routine air-conduction testing and result in sufficient ambient noise reduction for bone-conduction testing with most patients. There is no clinically significant occlusion effect from NCE during routine bone-conduction audiometry. These findings support the utility of using NCE for offsite audiometric testing.
Keywords: Behavioral measures; instrumentation; medical audiology; noise.