Date of Award
Doctor of Audiology (AuD)
School of Communication
Melinda F. Bryan
The purpose of this study was to determine Bluetooth headset specifications and its potential effects on hearing loss. The following research questions were assessed: (1) what is the maximum peak output of various Bluetooth headsets coupled to a cellular phone; (2) what is the average output of various Bluetooth headsets coupled to a cellular phone; and (3) what is the frequency response of various Bluetooth headsets coupled to a cellular phone? Sixteen Bluetooth headset devices of various manufacturers were used for this study. Bluetooth headsets used for this study were determined by consumer demands and lack of output specifications provided by their manufacturers. Each Bluetooth device was coupled to a Blackberry Curve cellular phone and volume level was set to maximum intensity for both devices. Sound pressure levels were obtained for each Bluetooth device using KEMAR to measure average SPLs using the A-weighted scale and a speech stimulus at input levels of 50, 70, and 75 dB SPL and a 90 dB SPL input swept-tone. SPLs measurements were also obtained using a 2cc coupler for a 50, 70, and 75 dB input speech stimulus and a 90dB swept-tone. The results revealed that most Bluetooth devices measured on KEMAR produced peak and average SPL values greater than 90 dBA SPL using a 70 and 75 dB SPL input speech stimulus and a 90 dB SPL swept-tone. Measurements obtained on a 2cc coupler showed that most Bluetooth devices produced mean averages of 90dB SPL or more using a 70 and 75 dB SPL input speech stimulus. Mean peak values exceeded 100 dB SPL with a 70 and 75 dB input speech stimulus. Additionally, frequency response for most Bluetooth devices measure on KEMAR and 2cc coupler produced a relatively flat frequency response in the low frequency range, peaked around 2500 Hz, and then rolled-off. Overall, most Bluetooth devices coupled to a cellular phone produced SPL values that exceeded OSHA standards. Therefore, Bluetooth devices used for an extended amount of time could possibly but hearing sensitivity at risk resulting in temporary and/or permanent hearing loss.
Anderson, Kristi Ann, "" (2012). Dissertation. 345.