RjDj is an iPhone app that take the sound input from your headset mic and then does different things to it – mixing it with a soundtrack or samples, reverbing or delaying or rapidly panning it.

You can download scenes or journeys, which provide different elements of interaction between you and the sounds.

The blurb and reviews tend to talk of dreams, trips and experiences. Maybe that points to a demographic less discerning than that of radio features. For me, RjDj has been hit and miss, and the hits, are only just the occasional curiosity.

The most acclaimed “Soundtrip” is called Eargasm. Hear Roman Mars, no less, sing it’s praises in 99% Invisible. This one left me cold. Funny sounds. Gosh. More successful for me has been Radiostory (maybe it’s in the name), which is under Moovz rather than soundtrips. Works nicely enough on the tube. Breathe was the most engaging in the latest test, wandering round the West End of London after work on a warm evening. Using the app did change my interaction with the crowds of people drinking in clumps on the street – I found myself walking closer to them rather than further away to see what the app would do to their sounds. Sadly it felt like bugger all. But perhaps something designed to induce disconnect, in an already disconnected environment, when you have earbuds sealing you off too, is just on too much of a downward spiral.

It has reminded me of the time when, aged 13, as the class was making NOISE with the teacher out, I put my fingers in my ears (or over that little stickey-out bit, I think) but kept looking round, and was rather impressed by the effect. This too makes me thing RjDj just ain’t targeting me. It certainly only raises slight interest.