Sonotone 1010

The Sonotone 1010 hearing aid, in 1952, was the was the first commercial product to use transistors, which had been invented five years earlier in 1947.

cite news
last = Fildes
first = Jonathon
title = Switching on the digital world
pages = 1
publisher = BBC News
date = 2005-11-15
url = http://news.bbc.co.uk/2/hi/technology/7081270.stm
accessdate = 2007-11-16