VO can be used effectively to counsel the patient in locating and operating BTE hearing aid user controls. Figure A (inline image below; A+B=13k) demonstrates a VOE (video oto-endoscope) view of the M-T-O switch. The patient's finger is brought into the video field while observing position the video monitor and experiencing simultaneously the acoustical effect of switch manipulation.
Next, the volume / gain control (VC/ GC) is located with VOE (Figure B). The operating finger is brought into the video field allowing the patient to correlate perceptually the (1) degrees of VC rotation; (2) loudness change experienced and (3) numeric VC/GC setting.