Abstract: A hearing protection device for insertion into an ear canal of a mammalian subject, comprising a first adjustable acousto-mechanical element. The first acousto-mechanical element comprises: a first portion having an opening which forms at least part of a sound path; a second portion configured to at least partially close the opening; and an actuation portion configured to exert a force on the second portion. The force exerted by the actuation portion causes at least part of the second portion to move towards/away from the first portion, varying the dimensions of the opening to alter an acoustic response of the sound path.

Abstract: This invention relates to a source for emitting radiation in the infrared range comprising a thin membrane including a radiation element made from a semi-conductive material having a chosen dopant, the radiation element being connected to a frame, the frame comprising connector means for connecting to a power source for conducting an electrical current through the substrate, the radiation element being provided with a periodic modulation of the refractive index constituting a photonic crystal having a chosen period, thus defining an optical resonator at one or more chosen wavelengths, and wherein the membrane is mounted to the substrate through a number of conductor beams distributed along the membrane circumference so as to provide an even current distribution and thus even heating over the membrane.