The Dreampad device is functionally closer to a speaker than a phone, i.e. it does not emit EMR.   However, many people are concerned about radio waves emitted from phones.  For those who prefer to be cautious (including us), we suggest putting your phone on Airplane Mode when using it with the Dreampad.  In this mode, no radio signals can come in or go out, and the Dreampad app music will still play.   Alternatively, you can use the Dreampad Bluetooth. This emits EMR but at a miniscule level (for comparison purposes, think of your cell phone reaching a tower miles away vs. the Bluetooth which has a reach of about 33 feet).