4. Candidate ear ("study ear"): Pure tone audiometric thresholds of ≥50 dB HL for each testable octave frequency of 0.125 and 0.250 kHz, ≥ 70 dB HL for each testable octave frequency from 0.5 through 8 kHz and sentence recognition scores ≤50% at screening. Subject responses will be monitored for vibrotactile sensation, particularly for the low-frequency stimuli (e.g., 125 and 250 Hz). A frequency that elicits vibrotactile responses at levels below 70 dB HL will be considered "not testable" for hearing threshold and only those frequencies that are testable for hearing threshold will be considered for patient inclusion/exclusion in the study.