Light-Based Hearing Device
Fay et al (2013) report their assessment of 13 patients (8 males, 5 females) using a contact hearing device (CHD, an open-canal hearing device with a spectral range from 100 to 10,000 Hz) in tandem with a custom-molded, light activated tympanic contact actuator (TCA).
Thirteen patients were each fit binaurally (n= 26 ears) for an average of 117 days without signs of infection, inflammation, perforation or other damage to the ear. In essence, a deep- canal impression is obtained to acquire the physical characteristics of the ear canal and the tympanic membrane (TM). The TCA is created from the deep canal impression. Mineral oil is placed on the TM after which, the TCA is placed in situ. The authors recommend mineral oil should be replenished "regularly." For the purposes of their study, mineral oil was replenished weekly.
The TCA has six components: (1) the photodetector receives light and converts it from light to electrical energy, (2) the peritympanic platform is used to hold the TCA in place, (3) the microactuator converts electrical energy into mechanical motion, (4) the umbo platform directly contacts and vibrates the TM, (5) the support springs allow flexibility between the chassis and the microactuator, and (6) the grasping tab is used to place and remove the TCA.
The authors report maximum gain of 40 dB (across 10kHz) before feedback occurred (in their assessments) and they note "real-world" gain is likely to be 7 to 10 dB greater. Fay et al suggest the CHD can reasonably be expected to deliver broad spectrum (up to 10kHz) amplification for people with up to an 80 dB hearing loss.
For More Information, References and Recommendations
Fay JP, Perkins R, Levy SC, Nilsson M, Puria S. (2013) Preliminary Evaluation of a Light-Based Contact Hearing Device for the Hearing Impaired. Otology & Neurotology 34:912-921.