New app to convert your cell phone into personal concert speaker

Open-air music festivals often have poor sound quality, but that could soon change, courtesy an audio-enhancing app for cellphones.

Researchers at the Technical University of Denmark, led by Jakob Eg Larsen, have developed an application that could convert your mobile phone into a personal concert speaker, reports New Scientist.

The result is an augmented listening experience in which every note could be heard clearly through headphones.

The researchers carried out experiments during two performances at the Nibe music festival in Denmark last June and involved 19 test participants who used the application on their mobile phones to augment their sound experience at the concerts.

A mixing device on the stage usually sends certain frequencies to an FM radio antenna that broadcasts the signal to phones at the gig.

Since simple portable radio won't work as a receiver, the FM signal must be delayed once it reaches the phone in order to align with sound from the stage.

The phone's GPS sensor measures how far it is from the stage, and the software calculates the necessary time delay.

Several study subjects reported that the sound was ‘clean’ and were able to hear the vocals and guitars clearly.

However, there are a few limitations also - the time it takes to process the sound means that listeners can't get closer than 60m to the stage speakers or the concert sound will arrive before the FM signal is played through the headset.

The second problem is that the GPS sensor in the phone cannot provide perfect location data, so users need to fine-tune the time delay manually.

The researchers hope their application could also be used at other live events like outdoor theatre and sports events.

However, experts said that the application might not work in practice because most mobiles in the market do not have an FM radio.