PVDF-Based Piezoelectric Microphone for Sound Detection Inside the Cochlea: Toward Totally Implantable Cochlear Implants.
Steve Park, Xiying Guan, Youngwan Kim and 5 others
PMID 29732950WHAT IT FOUND
A prototype cochlear-implant microphone made from a pressure-sensitive film detected cochlear pressure in animal and cadaver tests.
It is not a tested clinical device, and its signal was noisier than a hearing aid microphone.
Key findings
01In the gerbil cochlea, the prototype's output tracked the reference pressure measurement well until about 9 kHz, where it dropped by more than 10 dB.
02The prototype's phase response showed the familiar middle-ear delay, about 25 to 30 microseconds, matching the reference sensor.
03In cadaveric testing, the hearing aid microphone had about 10 to 20 dB better signal-to-noise ratio than the prototype between 100 and 10,000 Hz.
STILL TO COME
How it was doneWhat they foundWhat it means for SLPs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
No living patients or cochlear implant users were tested, so this cannot show hearing benefit or clinical safety. The gerbil device was too large to insert deeply, so the gerbil test was only a limited check that cochlear fluid pressure could be monitored. The cadaveric response dropped at higher frequencies, and the authors state that high-frequency behavior, amplification, and shielding need further study. The prototype's signal was noisier than a hearing aid microphone, so it is not ready for clinical use.
Declared interests
Measurement Specialties provided the PVDF films, and the article is tagged as supported by a non-U.S. government source. No full conflict-of-interest statement is included.
The easy way to misread this
Do not read this as evidence that a totally implantable cochlear implant improves hearing. The device was tested only in a gerbil and in cadaveric human ears, and its signal was noisier than a hearing aid microphone.