Light-Driven Contact Hearing Aid for Broad-Spectrum Amplification: Safety and Effectiveness Pivotal Study.

OBJECTIVE: Demonstrate safety and effectiveness of the light-driven contact hearing aid to support FDA clearance. STUDY DESIGN: A single-arm, open-label investigational-device clinical trial. SETTING: Two private-practice and one hospital-based ENT clinics. PATIENTS: Forty-three subjects (86 ears) with mild-to-severe bilateral sensorineural hearing impairment. INTERVENTION: Bilateral amplification delivered via a light-driven contact hearing aid comprising a Tympanic Lens (Lens) with a customized platform to directly drive the umbo and a behind-the-ear sound processor (Processor) that encodes sound into light pulses to wirelessly deliver signal and power to the Lens. MAIN OUTCOME MEASURES: The primary safety endpoint was a determination of "no change" (PTA4 < 10 dB) in residual unaided hearing at the 120-day measurement interval. The primary efficacy endpoint was improvement in word recognition using NU-6 at the 30-day measurement interval over the baseline unaided case. Secondary efficacy endpoints included functional gain from 2 to 10 kHz and speech-in-noise improvement over the baseline unaided case using both omnidirectional and directional microphones. RESULTS: The results for the 86 ears in the study determined a mean change of -0.40 dB in PTA4, indicating no change in residual hearing (p < 0.0001). There were no serious device- or procedure-related adverse events, or unanticipated adverse events. Word recognition aided with the Earlens improved significantly (p < 0.0001) over the unaided performance, by 35% rationalized arcsine units on average. Mean functional gain was 31 dB across 2 to 10 kHz. The average speech-recognition threshold improvement over the unaided case for the Hearing in Noise Test was 0.75 dB (p = 0.028) and 3.14 dB (p < 0.0001) for the omnidirectional and directional microphone modes, respectively. CONCLUSION: The safety and effectiveness data supported a de novo 510(k) submission that received clearance from the FDA.

Extended High-Frequency Bandwidth Improves Speech Reception in the Presence of Spatially Separated Masking Speech.

OBJECTIVES: The hypothesis that extending the audible frequency bandwidth beyond the range currently implemented in most hearing aids can improve speech understanding was tested for normal-hearing and hearing-impaired participants using target sentences and spatially separated masking speech. DESIGN: The Hearing In Speech Test (HIST) speech corpus was re-recorded, and four masking talkers were recorded at a sample rate of 44.1 kHz. All talkers were male native speakers of American English. For each subject, the reception threshold for sentences (RTS) was measured in two spatial configurations. In the asymmetric configuration, the target was presented from -45° azimuth and two colocated masking talkers were presented from +45° azimuth. In the diffuse configuration, the target was presented from 0° azimuth and four masking talkers were each presented from a different azimuth: +45°, +135°, -135°, and -45°. The new speech sentences, masking materials, and configurations were presented using low-pass filter cutoff frequencies of 4, 6, 8, and 10 kHz. For the normal-hearing participants, stimuli were presented in the sound field using loudspeakers. For the hearing-impaired participants, the spatial configurations were simulated using earphones, and a multiband wide-dynamic-range compressor with a modified CAM2 fitting algorithm was used to compensate for each participant's hearing loss. RESULTS: For the normal-hearing participants (N = 24, mean age 40 years), the RTS improved significantly by 3.0 dB when the bandwidth was increased from 4 to 10 kHz, and a significant improvement of 1.3 dB was obtained from extending the bandwidth from 6 to 10 kHz, in both spatial configurations. Hearing-impaired participants (N = 25, mean age 71 years) also showed a significant improvement in RTS with extended bandwidth, but the effect was smaller than for the normal-hearing participants. The mean decrease in RTS when the bandwidth was increased from 4 to 10 kHz was 1.3 dB for the asymmetric condition and 0.5 dB for the diffuse condition. CONCLUSIONS: Extending bandwidth from 4 to 10 kHz can improve the ability of normal-hearing and hearing-impaired participants to understand target speech in the presence of spatially separated masking speech. Future studies of the benefits of extended high-frequency amplification should investigate other realistic listening situations, masker types, spatial configurations, and room reverberation conditions, to determine added value in overcoming the technical challenges associated with implementing a device capable of providing extended high-frequency amplification.

Preliminary evaluation of a light-based contact hearing device for the hearing impaired.

OBJECTIVE: To assess the safety, stability, and performance of the broad-spectrum, light-based contact hearing device (CHD) on listeners with hearing impairment. STUDY DESIGN: Feasibility study. SETTING: Single-site research and development facility. PARTICIPANTS: Thirteen participants with symmetric mild-to-severe sensorineural hearing impairment had the CHD placed bilaterally. INTERVENTION: A custom-molded light-activated tympanic contact actuator (TCA) was placed into each ear by a physician, where it stayed in contact with the umbo and a portion of the medial wall of the ear canal for 4 months. Each CHD was calibrated and programmed to provide appropriate broad-spectrum amplification. MAIN OUTCOME MEASURES: Safety was determined through routine otologic examinations. Aided and pre-TCA-insertion unaided audiometric thresholds (functional gain), maximum gain before feedback, tympanic membrane damping, Reception Threshold for Sentences (RTS), and Abbreviated Profile of Hearing Aid Benefit (APHAB) measurements were made to characterize system performance as well as the benefits of amplification via the CHD. RESULTS: The TCAs remained on participants' ears for an average total of 122 days, without causing signs of inflammation or infection, and there were no serious device-related adverse events. Measured average maximum output of 90 to 110 dB SPL in the range of 0.25 to 10 kHz, average maximum gain before feedback of 40 dB, and functional gain through 10 kHz show extended-bandwidth broad-spectrum output and gain. RTS results showed significant aided improvements of up to 2.8 dB, and APHAB results showed clinically significant aided benefits in 92% of participants (11/12). CONCLUSION: The safety, stability, and performance demonstrated in this initial 4-month study suggest that the CHD may offer a feasible way of providing broad-spectrum amplification appropriate to treat listeners with mild-to-severe hearing impairment.