The text itself is crafted by production staff in our systems and then we distribute it to these platforms. I specifically wanted to talk here about 'the web' - and our IP delivery mechanism for LiveText - what I call 'LiveText-via-IP'.

You may have noticed that LiveText appears on many of our national radio networks' web sites and we had it on the original Radio Player through a Flash client. When we started this a few years ago, it was an initial offering that would give us some feedback about how we should implement the service fully... and whether we should implement it at all!

Having collated all the feedback, and reviewed the delivery solution - we started to plan a new infrastructure.

Meanwhile - new services that also provide content synchronous to our broadcasts were being trialled - we have previously spoken about our Visualising Radio trials - you can see the parentage from the LiveText service. So delivering other media-types synchronously with our live streams is just as important.

What we needed was a way of implementing an infrastructure that could replace our existing LiveText-via-IP service, making sure we can deliver that and provide a system that is scalable and stable for new services.

Through a tendering process we eventually agreed on picking an open-source protocol and a company known for its expertise for server side implementations. We chose XMPP PubSub as the technology, and ProcessOne as the company. (XMPP used to be called Jabber, just in case you knew it by that name.)

Some of the considerations we had around this tender process:

• we wanted an open-source protocol, to allow anyone to be access it and where libraries for consuming the 'messages' were available in a variety of languages
• if we were going to use open-source, then any development should give back to the community - in the end with ProcessOne's ejabberd server nodes any extensions are fed back into the development of ejabberd and XMPP protocol
• picking anything requires us to investigate the 'pedigree' of such a system - so we wanted something that had evidence of widespread deployment and scale of delivery (how many concurrent users can connect at once) - XMPP hit the mark
• we also wanted some flexibility - so a protocol and server that would allow us to deliver what we need right now (simple text strings), and then grow with our ambitions - the XMPP protocol might seem a little bloated for delivering simple text strings, but as we develop the LiveText service over the next few years it allows us to, for example, mark up different languages, alternative messages for different clients/services. It also lets us provide new services using the same protocol - so the learning curve is lowered and hopefully reusability of code is improved.

So - where can you see this in action right now?

On the websites we have upgraded our Flash-based LiveText clients so they are consuming messages from our ejabberd services. Check it out on Asian Network's homepage.

Our Flash clients are built using the XIFF client library - an open source ActionScript library - we made some tweaks that we're feeding back to the XIFF developers.

There are currently two connection methods for our XMPP service - direct connection through sockets or via BOSH over port 80. If you are behind a firewall that blocks the XMPP ports then your client will connect using BOSH.

If you are using Firefox and have the FireBug addon installed - you can see some comms in the console. If you are behind a firewall which blocks our sockets you will also see activity in the network activity section in Firebug - showing the BOSH connection - just look for 'http-bind'.

We are now referring to our infrastructure solution as 'PushFeeds'. (We couldn't keep referring to them as 'a set of nodes of ejabberd that provides XMPP PubSub and BOSH' - just too lengthy to repeat all the time!)

Coming up - we are looking at other places to put LiveText-via-IP, whether on our websites or syndication locations. Also looking at devices on IP that could support this. And, of course, other services that could take advantage of push messaging like this - I'll take this opportunity to ask any BBC Staff interested to check out our internal wiki pages about the service.

Alan Ogilvie
Interactive Platform Producer, Audio & Music Interactive

Further information:

• XMPP website
• XEP-0060: Publish-Subscribe - the XMPP PubSub specification
• ProcessOne - the company we worked with to setup our service
• XEP-0124: Bidirectional-streams Over Synchronous HTTP - the XMPP BOSH specification
• XIFF Actionscript client library
• XMPP librariesare available in many common languages, if you don't want to write one from scratch.
• ejabberd - the open source server technology behind our service, supported by ProcessOne
• ejabberd developer community - find out how feed into ejabberd development, or make use of the technologies
• BBC Wiki page (Internal) - an internal page for BBC staff to find out about the service. (Link only works from within the BBC network)

You can read more and comment on the Internet blog and there is more help on BBC iD here.

Before you read on, you should put your headphones on and listen to this...

With any luck you should have just had an interesting if not mildly disturbing sonic experience. And - by the way we don't really have your brain on a database; it was all just a sonic illusion..... As with all great Sci Fi special FX techniques it was done using a technique that was created a very long time ago and then re hashed in the 70s. The technique is called Binaural and has more or less been around since the dawn of broadcasting, when the French used it to broadcast operas though the telephone network to paying customers. It was originally patented in 1931 by Alan Blumlein as part of his pioneering research into Stereo for EMI.

Now if your not really interested in recording techniques you can stop reading now, as the rest of this blog will be as painful as sitting next to the really boring guy at a dinner party who talks about how the ABS in your car works...for hours. For those of you who are interested, you can read this and laugh at me, saying 'no, no, no - you so called BBC so called expert, you clearly have done it all wrong!'

Anyway, Binaural is a stereo recording and playback technique that tries to recreate sound in a three dimensional way. Surround sound for headphones. For true modern binaural recordings a 'dummy head' should be used with microphones placed inside replica ears, but there are a few variations on that theme. The basic idea is that two omni-directional microphones are placed a heads-width apart and are separated by a head-like object. So when listened to on headphones the sound appears as it would if you where really there. The drawback is that it only works on headphones and is in no way compatible with summed mono, i.e. the single speaker DAB radio in your kitchen. Also, as it is still just an illusion that tricks your brain, people can experience dummy head binaural in different ways. A common complaint being that all the sound seems to be coming from behind the listener.

A clever person has already written this wikipedia page on Binaural if you are interested in finding out more. And there's more on Dummy Head recording here. And a clear demonstration by a very nice chap on YouTube here. And there are other binaural shorts on You Tube including a virtual haircut which is fun;

BBC Radio Drama did an excellent play using binaural called The Revenge in the 70s with no dialogue. It's totally gripping and well worth a listen if you can find it. There are also many music recordings using binaural including some tracks on Pearl Jam's 'Binaural' album.

For the Planet B Immersive trail you just heard we actually used three different types of stereo. Those being 2 track Mono, L and R stereo and Quasi Binaural stereo.

The Quasi Binaural elements were captured in a few different ways. For the opening scene the voice of planet B says 'Thank you for choosing to upload your brain' while the probe moves around your head - we used two different techniques. For the vocal element I recorded the actress in a standard voiceover way with a Mono cardioid large diaphragm condenser mic; in this case a Neumann U87. This was then played back through speakers in the studio's live area positioned at opposite poles around a Jecklin Disk microphone array. (The disk was chosen over the dummy head for its better compatibility with data compression techniques).

The probe effect in the first scene was achieved by playing back the probe sound FX through a Fostex self powered speaker which was moved around the mic array manually. In the end it took three very quiet people to move the speaker, and my Phillips Shaver for extra intensity.

For the three scenes Spy world, Jurassic Adventure and Operation Extreme Glory, all the vocal elements were recorded using the Jecklin Disk, including the background voices in Spy World and the screaming soldiers in Extreme Glory.

The final binaural elements are the brain removal sequence. We again used the three person Fostex speaker dance for the sawing of the skull. The disk was then replaced by a melon and a coconut. These were operated upon with various implements and much fun was had by those of us listening on headphones to the squishing and scraping.

The rest of the sound design was done in L and R Stereo, and panned Mono using some spatial plugin's. It was all recorded, designed and mixed within the excellent Pro Tools HD. The in-studio SFX playback was done using Spot On play out software. We monitored using Sennheiser HD25-1s and Beyerdynamic DT250s. The recording console was a Studer Vista 6.

For me it was an interesting experiment in sound, combining different stereo techniques to create a unique listening experience. But really it was all down to the BBC Radio Drama Development team in coming up with such an excellent idea, and a brilliantly imaginative script!

Caleb Knightley is a Senior Studio Manager and Sound Designer for BBC Radio Drama.

• BBC Four uses the same stereo mix that's used for Radio 3. It's combined with the pictures and sent back to Television Centre via an MPEG2 (MPEG1 Layer II) link at 384kbps. No additional processing is carried out before encoding.
• BBC Four sound on Freeview, Freesat and Sky is transmitted (using MPEG2) at 256kbps with no processing or bandwidth limiting.

• Proms on BBC Two (and BBC One) use a dedicated sound mixing truck, to ensure that audio is mixed in a complementary way to the pictures broadcast. Proms also transmitted on the BBC HD Channel are usually mixed in surround sound using Dolby 5.0, though broadcast in Dolby 5.1 for technical reasons.
• Stereo for BBC One, BBC Two and BBC HD is sent back to Television Centre via an MPEG2 (MPEG1 Layer II) link at 384Kbps.
• When available surround sound is sent back in the same link using Dolby E encoding at 2Mbps (Dolby E can support up to 8 channels).
• Stereo is transmitted on BBC One, BBC Two at 256kbps (MPEG2), and 256kbps (MPEG4) on BBC HD.
• Surround sound is transmitted on BBC HD at 384kbps using Dolby Digital encoding. Dolby Digital has a frequency range from about 3 Hz to 18 kHz.
• Only the surround sound mix is transmitted on BBC HD. If an HD set top box is set to "Stereo" it uses the additional data (Dolby Metadata) we send in the Dolby Digital signal to create a stereo mix.
• BBC television analogue services use NICAM-728 encoding the stereo signal at 728kbps for transmission.

At BBC Radio we try to deliver the best experience for users of our streaming services. We constantly review our services to make sure they deliver 'public value'. The four drivers of public value are: Reach, Quality, Impact and Value.

When streaming services are evaluated against these measures, we take into account where different formats might need to be implemented, evolved or deprecated.

The streaming service provided in RealMedia format has been with us at the BBC since 1996. At the time it was the best option available, but more recently alternative methods of delivery have become just as important. These include Windows Media and Flash.

When evaluating services with our public value tests, which includes the costs of the services, we came to the decision that RealMedia was something we needed to phase out.

The actions to phase out RealMedia are broken down as follows:

• National networks - e.g. Radio 2, Radio 6Music, Asian Network, etc
• Nations - e.g. BBC Radio Scotland , BBC Radio Wales, etc
• Local Radio - e.g. BBC Cumbria, BBC Bristol, etc
• WorldService - the English language streaming service in iPlayer only - international World Service streams are unaffected.

It was clear that we could easily plan for a migration period for National networks during which RealMedia and alternatives will be available and allow for our audience and third-parties to make changes in a reasonable period.

So we'll be phasing out RealMedia by 30 March, 2010 for National networks.

In order to improve the experience in the BBC iPlayer web interface, we'll change the lower bandwidth option from its current RealMedia offering to a new Flash offering at 48kbps. We hope for this to be completed in October.

The legacy RealMedia streams will continue to exist on our systems until the March deadline, so that it gives those who still use them time to migrate to using the alternative:

• Windows Media for Live streams - available globally for these services
• Windows Media for Listen Again streams - will phase in over the next few months and be available globally.

The technology used for Nations and Local Radio services is more restrictive and a more difficult decision had to be made. A migration period would not have been possible without a significant increase in equipment which could not be justified. We had to make the unfortunate decision to switch off RealMedia as we simply could not offer both RealMedia and Windows Media at the same time.

In addition to the disruption caused to the Listen Live services, an unforeseen dependency means that the Listen Again service in Windows Media won't be operational until November.

Due to differences in production, World Service live and on-demand streams will continue to be available in Flash, RealMedia and Windows Media formats. However, if you access our content through BBC iPlayer it will only be available in Flash. Links to RealMedia and Windows Media versions of our programmes will be available from bbcworldservice.com.

Mark Kortekaas is Future Media Controller, A&M and Mobile Media

• BBC iPlayer: if you're experiencing a problem with audio streaming, please take a look at the site's help section where you can find FAQs about the service and a contact form for any specific queries. Some specific FAQs you may find useful:
  • "Why am I no longer able to 'Listen Live' in BBC iPlayer to my local BBC radio station in RealMedia format?"
  • "Why am I no longer able to 'Listen Again' to BBC local radio programmes in Real Media format?"
  • "Why am I no longer able to listen to my local BBC radio station through my Internet Radio device?"
  • "Where can I find the Windows Media and Real streams for local BBC radio stations and BBC World Service?"
  • "Where can I find the Windows Media and Real streams to listen live to National BBC Radio?"
• Blog comments: we're always open for discussion and we want to hear what you think of these changes, so please do post your comment below. We'll be reading them and will try to respond soon. however if it's a specific problem you're experiencing it's easier to use the iPlayer help section.

I think the easiest way to understand it, is it lets you plug things into other things to produce very cool things, without the need to write a single line of code. These things are called patches and Apple provide a whole library of them (even more in Snow Leopard). These patches wrap low level functionality in them like OpenGL , Core Image, Core Video, Bonjour Services, Apple Remote Access, Midi, XML loading and parsing etc, without you needing to understand the underlying technologies. You can also write your own patches including the ability to incorporate JavaScript to effect the patches results. A patch is like a function, you pass it some information and it returns results, without you needing to care what happens inside.

So, with all these patches, you create a composition, which is a file with a .qtz extension. Here's an example of what a composition looks like:

A composition can be ran stand-alone, exported as a QuickTime movie, or used in a Cocoa application. It can also be used as a Screen Saver or iTunes visualization simply by dragging it into the correct folder on your Mac. A patch can also be nested in a patch, so as you can imagine the compositions can get quite complex.

One of the limitations of the initial version of QC was that you could only load RSS feeds and not arbitrary XML. Luckily this had been addressed in the new version, so as well as all the other awesome new patches, there's one that lets you provide a path to some XML, and handles downloading and parsing into a structure, as well as download progress information and a flag for when the data is ready.

With this new functionality as well as other new patches, I have created a composition that rolls through the BBC's National Radio networks and displays who is currently on air, as well as downloading and displaying the network logo and a pretty image for that show. Here's a screen grab:

You can download the composition here:

BBCRadioNow1.1.zip

To install you need to:

1. Make sure you are running OSX 10.6 (It won't work otherwise)
2. Unzip the downloaded file
3. Move the BBC Radio Now.qtz file into your Screen Savers directory.

   /Users/<username>/Library/Screen Savers

4. NOTE: You may need to create the Screen Savers directory if it doesn't exist

Now you can go to the Screen Savers settings page in system preferences, and you will be able to choose BBC Radio Now from the left hand menu. You can also adjust the duration in which the radio stations are switched via the options tab. Oh and remember, if you're not connected to the internet then you won't see anything.

Disclaimer: I made this as an unsupported demo for my own learning. If you find any problems and fixes, please post them in the comments

From in-depth description …

"Some bands in no particular order: The Beatles, Elvis, Bowie, Talking Heads, Elvis Costello, Jonathan Richman, Orange Juice, Iggy Pop, Velvet Underground, The Specials, The Only Ones, The Clash, Radiohead, The Pixies; generally I like all Punk and New Wave (especially the one-hit wonders) between 76 and 84 - after that the horror of the New Romantic era put me off listening to music on the radio; another strand is early 60s girl bands like
The Shangri-Las, The Crystals, The Shirelles - well, all of them really; also a big fan of Louis Jordan and that whole 40s jumpin’ jive sound. I used to do the Camden live music pub circuit, both playing and to listen to the other bands. My classical taste is limited, though I know I’m more Beethoven and Bach than Mozart or Schubert.
"

"Interesting… when I started thinking about my taste I often like specific artists, but not necessarily the whole genre they’re in, e.g, in jazz music I like Monk and Bill Evans, in jazz funk I like Herbie Hancock and Mahavishnu Orchestra. In dance music I like specific DJs like Sasha, John Digweed, but not Judge Jules or Pete Tong. Here it’s the DJs that are important, more than individual artists and producers. Deep house and garage - the early-mid 90’s US variety, not the later UK garage, or any of the other myriad garage genres. I like Tangerine Dream (before they went bad in the mid-90’s) and Klaus Schulze - “Berlin school” electronic music. What else? Classical music - Bach, Mozart, Beethoven (but more the string quartets than the symphonies)."

To brief ones…

" Eclectic, Eccentric and Elitist."

Then there was a bootleg album cover with "Lou Reed at a tacky Adelaide hotel (with - I think - Malcolm Young from AC/DC) after the first (and best) concert I ever went to". Or more visual representations…

"Here’s a stab at my taste. I realise that my taste is pretty much completely mood based. I have used genres to stop this taking months. I also kept it top level, as I could also have joined things like “Happy” and “Busy” together to produce a different result."

“I had to stop at some point so it’s not comprehensive. But it’s all about connections”

“If asked i’d show people last fm i suppose but thats not entirely accurate.this is a bit more reflective [a spotify playlist of my 500 favourites] and this [photo above] is highly accurate for one period in my life - my record diary when i was 13-17. or in 100words..at least today I like late80sindiepop,beatles,sunshinepop,folkrock,northernsoul,ska,late70sandlate80shiphop,70sdisco,abba,spectoresquegirlgroups,and cilladustysandieuk girlgroups, the first 50 releases on creation, roughtrade, postcard, 4AD, and Mute and lots of versions of Amazing Grace.”

"I like nothing from before 1960. First attempt had 1930 as year zero, but I realised I didn’t like anything from then! X axis shows when the music’s from, Y axis shows the time I first liked the group. I have been ruthless about exercising things I don’t like anymore. This isn’t to show how cool I always have been, but because this is a snapshot of ‘now’"

Obviously this is a small and select sample but some common themes emerged. About half were discursive and half were visual in some way. Most people mentioned specific bands or artists and musical genres, followed by record labels, songs and albums. There were lots of tag-like descriptions, “early 60s girl bands” for instance, identifying more niche genres or scenes and also mood-like descriptions. And there was quite a lot of personal history, obviously your taste changes over time. Also interesting was that some people defined their taste in terms of dislikes.

Paul over at the Music Machinery blog noticed I’d posted my musical taste to Flickr and he asked his readers to send him their representations of musical taste. So I thought I’d do the same over here. What are your musical tastes? How would you best describe them? Do you feel comfortable telling us? Is it too hard to describe? Answers in the comments or on Flickr (tag them MyMusicTaste) please.

Click here to explore the visualisation or read on to find out more.

After our recent hackday on music visualisation we ran a quick two week sprint with the R&D Prototyping team to develop a combination of the best and the most feasible of the ideas that came out. Radio Waves is the result of that sprint.

What it does

Initially the visualisation represents all four of the BBC radio stations we are using; BBC Radio 1, BBC Radio 2, BBC 1Xtra and BBC 6 Music. The graph represents how many albums were released by the bands and artists recently played by shows on that network - so if it has a peak in the 1950s then that network has played artists who were active in the 50s. The visualisation can then be filtered to show the graphs for a particular radio network, a genre or show.

Individual years within the graph can be selected to show a list of artists who released albums in that year and have been most played by the selected radio network or show. Clicking on an artist will show more detail about them and reveal the complete list of albums they released and when.

How it works

We start by collating the data for what music BBC Radio has played over the last few months - from tracklistings like this. Note that this prototype is only using a static data set for now. From this we can link to /music data about these artists, and from there to releases from each artist. From the complete list of releases we try to only use albums, not compilations, EPs or singles, as we believe that albums sufficiently represent an artist’s historical profile (this is arguable). We can then take the release dates of all these albums, and the number of times each artist has been played on that radio network or show, to draw the graph. In total we're using about 300 shows, each with a play count and top artists for every year and a list of about 9000 featured artists.

We have to tidy up the data a bit; not all tracks played have MusicBrainz IDs attached, we have to remove duplicate releases (there are lots of “disc 1” and “disc 2” in the MusicBrainz data) and we also remove any albums from “Various Artists” because that's not particularly helpful for our purposes. And we've left out Radio 3, Asian Network and the regional services because we don’t have that much play data from them at the moment. Radio 3 in particular would be difficult because the "releases" they play don’t represent a composer’s active career in the same way as releases for pop and rock bands do.

It’s a prototype

Radio Waves was built so we could explore the possibilities of visualising our music data and we deliberately constrained ourselves to only use data that we have available right now. We think it has one major but surmountable problem. Our current architecture and data mean we can only go from a show » songs » artists » albums » release dates. So this doesn’t actually represent the release dates of the music that is played on the radio, rather it represents the careers of the artists whose music is played and that’s not completely intuitive. Ideally we would go directly from show » songs » release dates, and at some point, with the help of the MusicBrainz next-generation schema and some dedicated volunteers, we should get this data.

As an end note, we probably also need to tidy up which album releases we use. If you look at the graph for Elvis you can see his original career (he reportedly died in 1977) and then a resurgence in popularity (and therefore re-releases, sessions, best-ofs…) in the last decade. So maybe we should limit the data to releases within the artist’s (or bands) lifetime.

Skim-read introduction to linked data slides

bbc:programme=b00lj1nc

That's it, the photo is now machine tagged. Machines can now discover that this photo refers to this programme. This is a rather trivial example; my radio tuned to Any Questions on BBC Radio 4. If you click through and check the tags on Flickr you'll see something that looks like the machine tag above.

So it might be that you took the picture because you really enjoyed listening to something, but more interesting would be a location of a show, or pictures from when you were in the audience, or maybe you've taken a picture of something or someone that was featured in a programme...

Statue of the Venezuelan revolutionary, Francisco de Miranda, as featured on In Our Time

By machine-tagging these photos you will be helping machines connect things together and create new paths for people to find both BBC programmes and your photos. Sites like Upcoming, last.fm, Dopplr, MusicBrainz and OpenLibrary already support machine tags and are often connected to Flickr. Some people are even machine tagging sightings of threatened wildlife. An event/place/book page can then point to the machine-tagged photo page on Flickr and the photo page can point back to the event/place/book page. And, of course, it's not just photos that you can tag like this, you could machine tag your blog posts about BBC programmes or your social bookmarks or even your tweets. As an example, the BBC could use machine tags to point to your photos from our programme pages or use them to illustrate a blog post.

All these machine tags will be helping to connect and link different pools of data on the web which are currently unconnected. And that's what the web should be about - linking things.

Search Flickr for bbc:programme machine tags...

Album covers from the charts are laid out as a treemap.

Filtering the charts by weather conditions.

The most played bands for each BBC music show.

Using CoolIris to render a wall of BBC shows.

Mapping the bands from BBC Introducing.

A Wordle of lyrics from the charts.

Graphing when a band released records (that's my own MacBook Air - no, the BBC doesn't give us these!)

We're picking this work up again now to take the best of these ideas and try to build something great. More soon.

On the weekend of 11th-12th July the Guardian kindly allowed a group of hackers to take over one of their offices to hack on music related projects. Patrick, Yves, Nick and I represented A&Mi. As well as helping others to work with /music and /programmes APIs, we spent the weekend building an automated DJ system which trawled the web of linked data (and other webservices with open APIs, echonest and last.fm for example) to create a continuously evolving playlist of music. A robotic voice then droned on with facts derived from the data. We called the resultant mash-up The Music Bore.

You can see the Bore at work in this video:

It was, as organiser Dave Haynes pointed out, significantly better than listening to Chris Moyles. We couldn't possibly comment.

In a moment of madness, we decided to implement the whole thing as a collection of inter-communicating IRC bots. Using IRC bots allowed us to work on and test the different parts in parallel, and to each use our favourite languages. We collaborated on shared code using github.

Yves worked on the playlist generation and fact-finding code using RDF and SPARQL queries. The exciting part of this work was that it allowed the playlists to be utterly unpredictable. Given an arbitrary starting point the Bore could follow many possible paths through the web of linked data. If you want to learn more about how this worked in practice, or how to mine linked data using these technologies, Yves recently blogged about that in detail.

Patrick built a suite of "fact-finders" which randomly generated facts for particular artists from a variety of sources. He also put together, in record time, the "controller bot" which drove the demo - probably the most impressive example of speed coding I've ever seen!

Nick worked on the audio generation, mp3-finding and re-encoding magic that was necessary to allow music to be played. A particularly interesting aspect for me was the use of JACK to allow programmatic volume fading and mixing of the different audio streams. I did some amateur natural-language generation work to make the bot sound a little more human. This involved turning abstract facts into human sounding sentences using some basic NLG techniques.

We were lucky enough to be awarded the last.fm category prize, and to our great surprise the "best in show" prize too. A testament to what can be achieved in 24 hours if you let 4 hackers use their favourite tools to build something they are passionate about; or a clear demonstration of the lack of judgement caused by sleep deprivation? You decide.

It's well worth taking a look at the list of other hacks produced. I especially liked the Music Zeitgeist visualisation of the lyrics of each decade of music, an iPhone app for displaying last.fm events on a map and this site for generating a "sounds of your city" radio station.

Hello, I'm Kate Arkless Gray and I'm working on an exciting project for the BBC World Service called Save Our Sounds. There are so many photographs and words to capture the world, but barely anything in sound. We want to put that right and so we're asking people to help us preserve "endangered sounds" by recording them and sending them in to us. We've created an interactive map that allows you to upload your audio and place it exactly where it was recorded. Other users can then click around and travel the world in sound.

Getting people to actually record sounds for us is a bit of a challenge, so we're trying to make it as simple as possible. The map uploader is very easy to use and allows you to submit .wavs and .mp3s. The .wavs get automatically converted to mp3 before appearing on the map, so that it doesn't collapse under the weight of the files.

The really exciting bit is that we've been working with AudioBoo which is a free iPhone app that allows you to record an upload sound to the web. If you do this, and tag your sound with "BBC_SOS" it gets fed straight into our map (well, the moderation queue at least) via an RSS feed. Geotags then enable the sound to be placed exactly where it was recorded. Clever stuff.

We have to remember that this is a worldwide project and we have to be wary of assuming that everyone has access to the latest gadgets and high speed internet connections. To help people over the technical hurdles we're also offering a postal option and giving out the World Service phone number so that people can "ring in" their sounds. Their calls are converted and delivered to us as mp3s so that we can check them and add them to the map. Admittedly the quality of phoned-in sounds won't reach broadcast standard, but we don't just want our audiomap to reflect technologically advanced areas of the world.

Digital Planet is featuring Save Our Sounds in next week's programme and they're asking for your help to presvere the sound of 56k modems, dot-matrix printers and floppy disk drives. Can you help?

You can visit the Save Our Sounds map at http://www.bbcworldservice.com/saveoursounds and follow them online at http://www.twitter.com/bbc_sos.

Yesterday BBC Backstage announced that this data is now available at two SPARQL endpoints hosted by OpenLink Software and Talis. If (like me) you're new to SPARQL (a kind of SQL for the web) the Backstage blog also has links to tutorials and examples. If you want more details about the kind of data we model the Programmes Ontology and the Music Ontology are good starting points. If you're more comfortable with relational databases please check out the /programmes database schema.

Read more and comment at the BBC Backstage blog and the BBC Backstage mailing list.