A Spectrum of Possibilities

Question:  A 3 month old girl is referred to you for hearing loss after passing a newborn hearing screening.  A sedated ABR was performed, and while you have the waveform printouts, you do not have the audiologist's report.  Upon review, you notice that when the polarity of the auditory stimulus was reversed, the waveform of the ABR inverted.  You notice that a cochlear microphonic peak is present.  What is the most likely diagnosis?  [Answer will be posted with next week's new question]

Answer to last week's question, "It's a Palsy!" (January 9, 2017):

Placement of a tympanostomy tube.