We are happy to offer this free (Windows) program which will allow you to run a continuous chanting loop on your computer.
Download and install. Then whenever you'd like to hear a continuous drone of Om-Ma-Ni-Pad-Me-Hum you can.
Note: This program was written in 2000. It's a bit on the antique side, but it seems to work just fine on most windows operating systems. But, as they say, your mileage may vary. We don't use the registry. So, if the program is not to your taste, or it misbehaves, just delete it and all will be removed.