Master's Theses


Communication Sciences and Disorders

Degree Name

Master of Science (MS)


In recent years, speech-language pathologists and audiologists have been made more aware of the need of infection control procedures. Routine use of clinical equipment may spread infection. Audiometers and tympanometers are included in this clinical equipment. The purpose of this study was to measure the level of bacterial growth on the earphone cushions of audiometers and probe cuffs tympanometers, which had been brought in for annual calibration. Twenty earphone cushions and a probe cuff form five tympanometers were swabbed and inoculated into culture plates which grew various types of bacteria. Mannitol Salts (MSA), T-soy, and T7 were three types of agar plates used to grow bacteria. Ten of the earphone cushion were then disinfected with a commercially available disinfectant towelette and inoculated onto culture plates isolating the same bacteria. Results showed that all 20 earphones cushions and four probe cuffs showed microbial growth. Nine of the 10 earphone cushions that were disinfected exhibited a noticeable decrease in bacterial growth. It was conclude form this study that bacteria can survive on the earphone cushions of audiometers and probe cuffs of tympanometers. It was also found that disinfecting equipment significantly reduces the growth of bacteria and decreases the risk of spreading injections to clients and clinicians. Based on these findings, a disinfecting procedure should be implemented following every use of audiometer earphone cushion and probe cuffs of tympanometers in all settings.


Frederick Britton

Date of Award

Spring 1998

Document Type

Thesis - campus only access


© 1998 Jennifer J. Fuertges


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