Real-ear output measures of ear level fluency devices

Abstract

Objective: The purpose of this study was to measure real-ear aided and saturated responses of SpeechEasy^™ devices and compare responses while devices delivered altered auditory feedback (AAF) and non-altered feedback (NAF). Design: A repeated measures quasi-experimental design was employed. Study sample: Ten people fitted with completely-in-the-canal or open fit behind-the-ear devices participated. Probe microphone measures were obtained with speech, and 17 chirp stimuli presented at 75 dB and 85 dB SPL, respectively. Measurements were compared with devices delivering AAF (i.e. delayed and frequency shifted) versus NAF. Results: Maximum outputs were approximately 100–105 dB SPL in the 2000–4000 Hz range. Statistically significant differences in device SPL output as a function of device setting (AAF vs. NAF) were found for seven chirp stimuli (p <.05) when levels were sampled at points that were not temporally aligned with the output chirps but not for speech stimulus (p = .17). Device output varied across individuals and with open fit devices dominated by ear canal resonance effects. Conclusions: Real-ear aided responses were equivalent with speech input when devices delivered AAF and NAF. Real-ear saturated responses were not, however, comparable between AAF and NAF settings and may be underestimated if AAF delay is not accounted for.

Key Words::

• Instrumentation
• assistive technology
• hearing conservation
• noise

Acknowledgements

Qiang Wu, Ph.D., Department of Biostatistics, East Carolina University, provided statistical consultation.

Declaration of interest: The first author acknowledges a potential conflict in that he is a co-inventor of the SpeechEasy^™. The first author also discloses a financial interest in the form of minority ownership of non-voting common stock in Janus Development Group, Inc., the company that manufactures the device. The remaining authors report no declarations of interest.