Hello all,
In general, when we hear using bone conduction (BC), we should expect to hear the same or better than when we hear using air conduction (AC) due to the physical properties of the ear. With poorer BC thresholds, generally the culprit that is offered in clinic is poor bone oscillator placement. However, there are patients who demonstrate BC thresholds that are up to 30dB poorer than AC thresholds at 0.5kHz in particular, which placement would not account for alone. Other frequencies do not produce this same effect. Additionally, movement of the oscillator can result in no change in this AC/BC difference.
Aside from bone oscillator placement, are there other reasons that could produce a BC threshold at 0.5kHz that is 20-30dB worse than AC threshold? I've started to consider variability in bone density, force of the oscillator on the temporal bone (Toll et al., 2011), the differences in properly calibrated oscillators... I am open to any thoughts or research articles recommended by this group to assist my finding an answer to this question.
Thank you in advance for your assistance!
Wishing you all the best,
Becky Lewis
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Rebecca
Lewis, PhC
Doctorate of Clinical Audiology (AuD) Student
Doctorate of
Philosophy (PhD) Candidate
Speech and Hearing
Sciences, University of Washington - Seattle
Expected Graduation Date: 6/30/2016