If you see a chap walking around the fields of the Glastonbury festival this week with a weird looking pocket on the front of his t-shirt showing off his mobile phone, don't mock him for being a nerd - applaud him for his dedication to mother earth.

For you see, that chap won't be wearing the latest must have geek-chic, but rather a bonkers phone charging prototype, dubbed the Orange Sound Charge.

The system works by harnessing sounds and turning them into energy that power up the phone within. Don't worry - it's not 1 April, we checked.

It's all down to the findings of "months of planning and development" between Orange and renewable energy expert GotWind.

By covering the phone in a Piezoelectric film, which is usually found hi-fi speakers, the makeshift microphone absorbs sound pressure waves that are converted via the compression of interlaced quartz crystals into an electrical charge.

With sound levels of around 80dB, the Orange Sound Charge will generate up to 6 watt hours (W/h) of power over the weekend which is enough to charge two standard mobile phones or one smartphone.

The Piezoelectric film panel and electronics are all fully removable too, which is handy as Glastonbury clothing tends to get a tad muddy.

Andrew Pearcey, head of sponsorship at Orange UK said: "In a vibrant festival environment such as Glastonbury, sound is such an obvious medium that it seemed like a natural fit to use it in the development of this year’s prototype.

"Orange’s commitment and ethos around innovation is as strong as ever and we envisage that this pioneering technology could really change the face of mobile charging in environments where eco charging solutions need to be found. It could even influence trends in fashion, with designers looking to integrate this passive charging solution into clothing."