Every week 11,000 volunteers at 300 hospital radio stations broadcast more than 10,000 hours of programmes. It is quite an achievement, and one which, in an era suffering not from any shortage of entertainment but rather from media overload, seems at first utterly anachronistic.

Who needs amateur radio when televisions, personal CD players, even laptop computers can be brought in from home?

When the very first hospital stations were launched 70 years ago, radio was an exciting new technology. In the US, there were five radio stations at the end of 1921; a year later, there were more than 500 - a rate of growth which makes the Internet look tardy. In 1922, the UK got its first radio station.

And even when the earliest stations still extant today started in the 1950s, the broadcasting world was very different. There was no FM, no commercial radio, and on TV no ITV, let alone BSkyB - the BBC broadcast on a single television channel, and only in the evenings.

Yet hospital radio has survived and prospered, and having served as a training ground for many of today's big names, it is still innovative. The Hospital Broadcasting Association can now be found online, and a Hospital Radio Website Guide offers links to 70 local stations.

These range from the tiny (Castle Mead Radio broadcasts to 36 beds at Hinckley and District Hospital) to the near-professional giants, and from the early pioneers (Bristol Hospital Broadcast Service dates from 1952) to the brand new.

So far, none has gone down the netcasting route. Then again, since not every clinician has access to a computer, bedside PCs to keep patients entertained may yet be some way off. But how long before at least private patients are offered modem points as standard?