In the normal mammalian ear, sound vibrates the eardrum, causing the tiny bones of the middle ear to vibrate, transferring the vibration to the inner ear fluids. The vibration propagates from the base of the cochlea to its apex along the cochlear partition. As essential as this concept is to the theory of hearing, the waveform of cochlear partition vibration has yet to be measured in vivo. Here...

The usual technique for measuring vibration within the cochlear partition is heterodyne interferometry. Recently, spectral domain phase microscopy (SDPM) was introduced and offers improvements over standard heterodyne interferometry. In particular, it has a penetration depth of several mm due to working in the infrared range, has narrow and steep optical sectioning due to using a wideband light...

Bearing fault can be detected using envelope demodulation of the bearing vibration signal in the resonant frequency band. Hence locating the correct resonant band is the key to successful application of the resonance envelope demodulation. A statistical criterion of the vibration signal can be used to guide the identification of the resonant band. However, a single criterion is often not robust...