The 2^nd year student had been working with indirect supervision, conducting air-conduction testing and then bone- conduction testing.  At this point in testing the preceptor came in. The student said “the patient’s hearing is improving!”  The preceptor said “I doubt it.  What’s your mistake?”  The student indicated that she knows she still needs to test left bone conduction.  The preceptor indicated that while that was true, something else is fundamentally wrong.

Once the problem was resolved, it showed no hearing remaining in the left ear.

• What did the student do wrong?