The first commercial digital hearing aid was created in 1987 by the Nicolet Corporation. The hearing aid contained a body-worn processor that had a hardwire connection with an ear mounted transducer. While the Nicolet Corporation’s hearing aid was not publicly successful and the company shortly folded, it was able to start a competition between companies to create more effective hearing aids. Two years later, in 1989, the behind-the-ear (BTE) digital hearing aid was launched. In addition to the Nicolet Corporation, Bell Laboratories expanded upon the hearing aid business by developing a hybrid digital-analog hearing aid. When the hearing aid was put on in the market, it was instantaneously successful. This development helped bring major changes to the world of the hearing aid. The next major milestone was creating an all-digital hearing aid. The Oticon Company developed the first digital hearing aid in 1995, but it was only distributed to audiological research centers for research on digital technology in the realm of acoustic amplification. The Senso was the first commercially successful, all-digital hearing aid, and was created by Widex in 1996. After the success of the Senso, Oticon began marketing their own hearing aid, the DigiFocus. Presently, the digital hearing aid is now become programmable. By making the hearing aid programmable, it has allowed hearing aids to be capable of regulating sound on their own, without using a separate control. The hearing aid can now adjust itself depending on what environment it is in and often does not even need a physical volume control button. Square, silver metal hearing aid with electronics and AA battery compartments. Has an ear piece and ear mould attached by wire, with a volume adjustment. A body level type, probably a CALAID T manufacture from 1955 to the 70's. On front "C OF A/CALAID/108499" deaf children australia, hearing aid, calaid, commonwealth of australia