Effect of bone-conduction harmonic distortions on hearing thresholds

Area of Science:

• Audiology
• Hearing Science
• Biomedical Engineering

Background:

• Bone conduction (BC) audiometry is crucial for diagnosing hearing loss.
• Accurate BC thresholds depend on the performance of bone vibrators (BVs).
• The Radioear B71 is a standard BV, while the B81 is an advanced model with lower distortion and higher output.

Purpose of the Study:

• To compare the performance of the Radioear B71 and B81 BVs in obtaining BC hearing thresholds.
• To determine if the B81's reduced distortion offers significant advantages in audiometry.
• To investigate the influence of tactile responses on BC threshold measurements.

Main Methods:

• Two audiometric tests were conducted with 20 normal-hearing subjects.
• Bone conduction thresholds were measured using both the Radioear B71 and B81 BVs.
• Thresholds were compared across different frequencies and hearing levels (HL).

Main Results:

• Significant differences between B71 and B81 thresholds were observed only at 250 Hz between 20-30 dB HL.
• At higher frequencies and levels, the B81 exhibited less distortion than the B71.
• Tactile responses interfered with threshold measurements before the B81's advantages could be fully realized at higher levels.

Conclusions:

• The advanced B81 bone vibrator offers limited advantages over the standard B71 in typical BC audiometry settings.
• Tactile artifact is a significant limiting factor in achieving superior BC thresholds with advanced BVs.
• Further research may be needed to mitigate tactile responses for optimal use of advanced bone vibrators.