Cochlea a protein motor called prestin on their outer membranes; it generates additional movement that couples back to the fluid–membrane wave. This "active amplifier" is essential in the ear's ability to amplify weak sounds. The active amplifier also leads to the phenomenon of soundwave vibrations being emitted from the cochlea back into the ear canal through the middle ear (otoacoustic emissions). Otoacoustic emissions are due to a wave exiting the cochlea via the oval window, and propagating back through the middle ear to the eardrum, and out the ear canal, where it can be picked up by a microphone. Otoacoustic emissions
Jock Stirrup was one of 200 public figures who were signatories to a letter to "The Guardian" opposing Scottish independence in the run-up to September's referendum on that issue. In June 2015 Stirrup joined the House of Lords' EU External Affairs Sub-Committee. From October 2015 Stirrup has been the president of the Pilgrims Society. On Remembrance Sunday 2014, it was announced that Stirrup would lead the efforts to raise one million pounds to enable a national memorial to the British service personnel who fought in Iraq and Afghanistan to be erected in central London. By March 2015 Stirrup was confident that the