At the time, few outside of a small band of scientists and sailors noticed what was one of the last century’s earliest scientific breakthroughs. On Christmas Eve, 1906, Reginald Fessenden, a Canadian inventor, broadcast the world’s first AM radio programme, which included him playing the song Oh Holy Night on the violin, from Marshfield’s Brant Rock in Massachusetts. A few shipboard radio operators at sea along America’s Atlantic coast were the only listeners to tune in.

One hundred years on and with AM — amplitude modulation — still widely used, the debate has begun over whether the frequency should be switched off in Britain.

In an era of high-fidelity competition, of digital radio and internet broadcasting, AM’s susceptibility to atmospheric interference and its low-fidelity sound, making it better suited to speech rather than music, have put it under pressure. It survived its first great challenge, when many music stations switched to FM in the 1960s and 1970s; now, however, leading radio groups are calling for the industry to unite in lobbying for AM to be turned off in 2010.

Not everybody agrees. While Capital Radio and Virgin Radio executives are keen to see an end to AM, their counterparts at groups including Emap, which owns Magic, are not.

After a recent announcement from Ofcom, the communications regulator, that it would launch a full consultation into the future of both AM and FM radio, commercial radio groups had until earlier this month to respond to a discussion document from the regulator. Ofcom suggested in The Future of Radio that the AM spectrum could be used for Digital Radio Mondiale (DRM). It has emphasised that the spectrum could still be used for AM in the future.

However, any future decision by Ofcom is unlikely to be simple, because Britain’s leading commercial radio groups appear to have very different opinions on the future of AM radio.

A spokeswoman for GCap, the largest radio company, said that the owner of Capital Radio had been “consistently calling for the Government to set a date for the switch-off of analogue, not just AM”.

It believed that turning off analogue — including the FM frequency — was a crucial step in driving digital forward, which it argued was the future of radio. Although GCap refused to say exactly when this should be done, it is understood that the company was pushing for about 2010.

Fru Hazlitt, chief executive of Virgin Radio, said that she was also keen to see an end to AM, highlighting its poor quality compared with FM and digital radio. Despite the number of listeners that AM still had, she did not want them to listen to Virgin on the wavelength because of its poor quality.

Ms Hazlitt added that it would not be commercially viable for Virgin to broadcast on AM after 2010: “I don’t want them listening to The Killers on AM and I’m sure The Killers don’t want people listening on AM.”

Yet Emap, which is working on its response to Ofcom, said that it would continue to broadcast on AM while there was still a sizeable audience. The group said that it had recorded a rise in Magic’s AM audiences and it was still too early in the development of digital radio to talk about AM or analogue switch-off.

Dee Ford, group managing director of Emap Radio, said: “We want people to be able to listen to their Emap Radio service of choice, whenever and wherever they want to — be that AM, FM, DAB or via their TV.”

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