Can't You Hear Me Knocking

Question:  A patient is referred to you for symmetric sensorineural hearing loss.  The audiogram shows borderline thresholds and a sharp drop at 4 kHz with some recovery at higher frequencies.  What is the most likely etiology of the patient's hearing loss?  [Answer will be posted with next week's new question]

Answer to last week's question, Layer Cake (September 14, 2015): 

The injection likely found its way into the superficial lamina propria rather than deeper into the thyroarytenoid muscle.  This renders the speech rough and raspy by affecting the normal mucosal wave.