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We report a programmable analog bionic ear (cochlear implant) processor in a 1.5-microm BiCMOS technology with a power consumption of 211 microW and 77-dB dynamic range of operation. The 9.58 mm x 9.23 mm processor chip runs on a 2.8 V supply and has a power consumption that is lower than state-of-the-art analog-to-digital (A/D)-then-DSP designs by a factor(More)
—This work presents a compressing-and-expanding, i.e., companding, strategy for spectral enhancement inspired by the operation of the auditory system. The companding strategy simulates the two-tone suppression phenomena of the auditory system and implements a soft local winner-take-all-like enhancement of the input spectrum. It performs multichannel(More)
Pulse oximeters are ubiquitous in modern medicine to noninvasively measure the percentage of oxygenated hemoglobin in a patient's blood by comparing the transmission characteristics of red and infrared light-emitting diode light through the patient's finger with a photoreceptor. We present an analog single-chip pulse oximeter with 4.8-mW total power(More)
Sounds originating from within the inner ear, known as otoacoustic emissions (OAEs), are widely exploited in clinical practice but the mechanisms underlying their generation are not entirely clear. Here we present simulation results and theoretical considerations based on a hydrodynamic model of the human inner ear. Simulations show that, if the cochlear(More)
The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Recommended by Stephen Voran We describe an FFT-based companding algorithm for preprocessing speech before recognition. The algorithm mimics tone-to-tone suppression and masking in the auditory system to improve automatic speech recognition(More)
W ith the world population aging rapidly, providing timely care for the elderly is becoming increasingly important. For instance, more than 5,000 people experience sudden cardiac arrest (SCA) every week in the US. The only definitive treatment for SCA is early defibrilla-tion—no more than six minutes from arrest to first shock. The chance for survival drops(More)
This study tested a time-domain spectral enhancement algorithm that was recently proposed by Turicchia and Sarpeshkar [IEEE Trans. Speech Audio Proc. 13, 243-253 (2005)]. The algorithm uses a filter bank, with each filter channel comprising broadly tuned amplitude compression, followed by more narrowly tuned expansion (companding). Normal-hearing listeners(More)
—We have developed a wearable, battery-free tag that monitors heart sounds. The tag powers up by harvesting ambient RF energy, and contains a low-power integrated circuit, an antenna and up to four microphones. The chip, which consumes only 1.0µW of power, generates digital events when the outputs of any of the microphones exceeds a programmable threshold(More)
We describe the concept of a bioinspired feedback loop that combines a cochlear processor with an integrated-circuit vocal tract to create what we call a speech-locked loop. We discuss how the speech-locked loop can be applied in hearing prostheses, such as cochlear implants, to help improve speech recognition in noise. We also investigate speech-coding(More)