The William Demant Holding Group was founded in 1904 by Hans Demant.

Hans Demant, whose wife had a hearing loss, went to London to get a hearing aid for his wife. That very same year, he became a hearing instrument agent and founded the company ’Oticon’ – actually the oldest of its kind in the world. After Hans Demant's death in 1910, his son William took over the business.

Already before World War I, Oticon increased its sales volume to cover the rest of Scandinavia and Saint Petersburg. In the twenties and thirties, William travelled around Europe and established a network of agents.

During World War II, Oticon started its own production due to the scarcity of goods, especially from the U.S., and also began to export hearing aids to other countries in Europe.

From the fifties to the seventies, a network of sales companies was established abroad. In 1954, the first of four managers was hired. In 1968, a new president was appointed. William handed over the managing of the company to the four managers.

In 1957, William and his wife Ida Emilie donated the Demant family's shares in the company to the Oticon Foundation. The Oticon Foundation's general aim is charity with particular emphasis on helping people with a hearing impairment, and today the Oticon Foundation is the main shareholder in William Demant Holding A/S with a holding of approx. 55-60%.

In 1973, the production facilities were expaned by a factory in Denmark and a factory in Scotland. In 1977, the Research Centre Eriksholm was inaugurated. Oticon Holding was established in 1983.

In 1991, a new and very flexible company structure was established to strengthen the knowledge-based organisation.

1995 became a year of major changes: in January, the Group acquired Bernafon – a hearing aid manufacturer based in Switzerland which is today a separate business unit in the William Demant Holding Group. In May, William Demant Holding was listed on the Copenhagen Stock Exchange. 

In 1997, Phonic Ear was acquired, and today Phonic Ear is a major company in the Personal Communication business unit where FM and wireless technologies are core technologies.

In 1999, the headset manufacturer DanaCom was acquired.

In 2000, Interacoustics (audiometers) was acquired, and now the company is a major part of the Diagnostic Instruments business unit.

The William Demant Holding Group acquired four major companies that have strengthened the distribution of hearing aids manufactured by both Oticon and Bernafon.