I'm very sceptical of this. I work in the hi-fi industry designing and testing loudspeakers. When you design a drive unit, speakery thing, you kind of spec what the frequency range is, for domestic hi-fi you're loudspeakers go from about 50Hz to 15KHz, for top of the range hi-fi systems it goes from maybe 10Hz to 25Khz and thats expensice and uses several drive units for each part of the range.
Now mobile phone speakers aren't hi-fi, the're not designed for pitch accurate reproduction of music, on the whole mobile phone speakers are crap and just squawk compared to hi-fi speakers.
You know when you're on a bus and someone's mobile phone starts ringing, and they have I dunno, a Coldplay ringtone, you've not going to be fooled that you at a Coldplay concert, its an annoying squawk that sounds like Coldplay.
Human hearing for single frequency tones goes up to about 17KHz, this decreases as you get older in your twenties, to around 13KHz. So for this device to work, your standard mobile phone loudspeaker needs to reach around 15KHz.
I don't believe it.