Abstract: Aspects of the present disclosure provide methods and apparatuses for estimating a biometric parameter using multiple sensors. As described herein, multiple sensors are strategically used to output with increased confidence a biometric parameter. Multiple sensors are strategically used to save power while determining an accurate biometric estimation. Additionally, multiple sensors are used to detect and categorize a sleep apnea event.

Abstract: Techniques for user authentication via in-ear acoustic measurements are disclosed. An in-ear device emits an acoustic signal and detects an otic response to the acoustic signal. A user signature is generated based at least on the otic response to the acoustic signal. The user signature is compared with a reference signature, to determine whether the in-ear device has changed users.