A model displays the world's smallest hearing aid at its Australian launch, in Melbourne on May 7, 2009. The 'Touch' hearing aid is 50 percent smaller than the second smallest external hearing aid and includes noise reduction technology that recognises and turns down background noise. The 'Touch' will be available to the 21 percent of the Australian population affected by hearing loss and is available in 75 different colour combinations. AFP PHOTO/William WEST (Photo credit should read WILLIAM WEST/AFP/Getty Images)