Based on new findings, the World Health Organization classifies cell phones as a potential cancer risk, much like exhaust from gasoline-powered vehicles and lead. For many people, it's just not practical or realistic to avoid cell phones altogether. And it may not be necessary, if one takes precautions for reducing exposure. The standard used by federal regulators may not be the best measure of safety, nor is it the best way to help concerned consumers reduce their exposure.
Moving a cell phone, or other mobile device, even an inch from the body can greatly reduce radiation exposure. Signal strength falls off as the square of the distance to the source. This means that if one doubles the distance to the source, which is from the cell phone to one's head, the signal strength would be four times less, since two squared is four. If one triples the distance, the signal strength would be nine times less, and so on.
In US Pat. App. No. 20110170730A1, “Safe In-Ear Earphones,” Zhu discloses a safe in-ear earphone for radiation protection, comprises earplug heads, sound cavities, acoustic wave transmission channels, a main body, a conductor and a plug. The channels are set between the sound cavities and loudspeakers. The acoustic wave concentrated orifices are between the loudspeakers and the acoustic wave transmission channel assemblies of the loudspeakers. The acoustic wave concentrated orifices and the acoustic wave transmission channels are sealed to form sealed small boxes in the main body. The shape of acoustic wave concentrated orifices is inversely conical. The acoustic wave is transmitted to the two acoustic wave channels via the acoustic wave concentrated orifices and then is provided to the ears plugged by two earplugs to listen. The safe in-ear earphone is used for high frequency magnetic field and intense radiation communication device such as mobile phone.
The Federal Communications Commission (FCC) recommendations stipulate keeping a cellphone up to 2.5 cm away from the users head. The acoustic channel of the present invention provides for a separation of 5-6 cm, i.e., 2 times 2, or 4 times as safe.    1. information on cellphone radiation levels found on this website http://reviews.cnet.com./2719-6602 7-291-4.html    2. information from iphone manual found on this website (http//idownloadblog.com/2011/03/07/dont-hold-your-iphone-too-close-to-your-head-apple-says-so/)Apple iPhone 4—Important Product Information Guide:    For optimal mobile device performance and to be sure that human exposure to RF energy does not exceed the FCC, IC, and European Union guidelines, always follow these instructions and precautions: When on a call using the built-in audio receiver in iPhone, hold iPhone with the dock connector pointed down toward your shoulder to increase separation from the antenna. When using iPhone near your body for voice calls or for wireless data transmission over a cellular network, keep iPhone at least 15 mm (5/8 inch) away from the body, and only use carrying cases , belt clips, or holders that do not have metal parts and that maintain at least 15 mm (⅝″) separation between iPhone and the body.
Thus, it would be advantageous to provide an acoustic channel to be attached to a mobile device speaker that is simple, efficient, economical and effective, thereby enabling the user to hear telephone conversations, but keep the device at a safe distance from the head and all his vital tissues.