I found my local B&Q (Nursling) selling Sound Asleep MP3 pillows for less than £10.
These are currently £14.89 in Argos and best price online I could find was £9.99 + P&P
* Provides soft music to help you relax when going to sleep.
* Built in speaker.
* Cover 50% polyester and 50% cotton.
* Filling 100% polyester.
* Sponge clean only.
* Do not tumble dry.
* Size (L)74, (W)48cm.