What moves (in) a tree cricket ear?

*To request access to the videoconference, email dsivak@sfu.ca

Synopsis

Whether it's mice, men or crickets, hearing depends on a delicate chain of events. Sound is first captured by an eardrum or similar organ which vibrates. These vibrations are then transmitted to sensory cells in a series of mechanical and sometimes fluid-mechanical steps, presumably in a manner that opens mechanosensory channels generating an electrical signal. Oddly enough, sometimes the flow of energy reverses and vibrational energy is known to leak out of the ear. This reversal of energy flow is thought to be a signature of an ‘amplifier’. But, what is this amplifier, and how does it move the cricket ear? In my presentation I’ll present some of the work we’ve been doing to understand the amplifier in an insect model system. In the first part, I will talk about what a new technique called optical coherence tomography has revealed by allowing us to measure the complex behavior of moving parts within the intact auditory organ.  In the second part, I will talk about how a detailed analysis of these motions can reveal a lot about the underlying amplification mechanism. I hope to convince you that there’s a lot of interesting physics even in humblest insects.