Currently 20% of of all radio listening is via digital
Plans to switch all national radio stations on to digital-only platforms at the end of 2015 were announced in the government's Digital Britain report earlier this week.
But groups representing radio listeners and the blind have expressed alarm about switching off analogue radio transmissions.
The announcement has come as a shock. After years tiptoeing around the question of whether radio should follow television in moving totally from analogue to digital broadcasts, the government has now grasped the nettle.
As a result, all national radio stations will disappear from the FM and AM wavelengths in six years' time, provided certain tests are met - and the government says it will do all it can to make sure this schedule is achieved.
It is a highly ambitious plan - "very brave, Minister", as Sir Humphrey would put it - not least because it risks the wrath of middle England.
When the BBC tried to move Radio 4 off its long wave frequency in 1992, furious listeners marched on Broadcasting House.
Imagine what they might do if they find that many millions of analogue radio sets are to become, to all intents and purposes, obsolete.
Already they are marshalling their forces.
Richard Lindley, chairman of pressure group Voice of the Listener and Viewer, said: "We are surprised and concerned at the announcement.
"There is still an argument as to whether the DAB system is the best way forward for digital radio. Many older listeners, for whom their existing analogue radios are a vital link with the outside world, will look on this proposal with alarm."
Radio is particularly important to the blind and partially sighted.
Leen Petrie of the Royal National Institute of Blind People says few digital radios are yet suitable for the blind, so new sets and a "switchover help scheme" - like that for digital TV - are essential.
"A help scheme has to provide them with equipment they can use as easily as they can use analogue" she said.
"It must also provide a telephone help service and, where necessary, an installer to come round to their house and explain it and set it up for them."
The government does not yet accept that a radio help scheme is needed or how it would be paid for.
There may be surplus cash from the television switchover help scheme, but it wants to use that for other purposes such as boosting broadband provision and local news pilot schemes for ITV.
It says it will conduct a cost-benefit analysis of its digital radio plans, and this will "help determine whether there is a case for a Digital Radio Help Scheme and, if so, what its scope might be".
Even without a help scheme, the switchover to digital will be costly - for the BBC, which must extend its digital transmitter network, and for the public.
There are 38 million cars, most of which cannot receive digital radio
There are well over 100 million analogue radios - many homes have five or six - of which around 35 million are in regular use, according to Ofcom. That's not counting the 38 million cars, most of which can't yet receive digital radio.
This means a bonanza for set manufacturers - and a bill for UK consumers.
But Tony Moretta of the Digital Radio Development Bureau, which co-ordinates the industry's plans, thinks all the problems can be overcome.
He says the industry will save money by not having to broadcast on both analogue and digital frequencies and the final decision to switch off FM and AM won't get the go-ahead until 50% of all radio listening is via digital - the current level is just 20%.
He also says the government and industry will do what is needed to achieve its switchover target of 2015.
DAB vs analogue
"I think we've got much better co-operation across the whole industry - the BBC, commercial radio, the car industry, the radio manufacturers, the retailers" he says.
"We're all headed in the same direction and I think that date is certainly achievable. It's going to be hard work but we can do it."
Meanwhile, music lovers and audio buffs are divided over the merits of digital radio versus analogue.
Some say the DAB system is inferior to the current FM transmissions, partly because more stations are being squeezed onto the service than were originally planned.
"DAB can sound relatively poor compared with FM transmissions," says Professor Malcolm Hawksford, of the Electronic Engineering department at Essex University.
"I suspect the system is now being used in a way the original engineers didn't conceive."
But you can also receive digital radio via digital TV, where there are fewer bandwidth problems. And fans of Sky, cable and Freesat say the sound quality through a home cinema system is excellent.
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