A method for providing elected sounds to a user of a cellular mobile phone, who is isolated from sounds of the environment, to increase his awareness regarding entities or events in his vicinity, comprising the steps of: a) storing a predefined collection of reference sounds in a database, these sounds include voices of friends of the user, their sound signatures or other sounds they produce; b) by said user, wearing sound isolating headphones, which are connected to his mobile phone; c) installing a mobile application on said mobile phone, said mobile application is adapted to: c.1) automatically activate a microphone of said mobile phone, when the isolating headphones are plugged into said mobile device; c.2) periodically compare in real-time, sounds received from the environment to said collection of reference sounds, wherein the sounds received from the environment consist of sounds received from the environment via said microphone and sounds received from a common friend regarding another friend that is nearby; c.3) selectively filter sounds out of the environment, which match one or more reference sounds from said collection of reference sounds according to predefined criteria, which includes selectively filter sounds out of the environment that are originated from friends of the user and which match one or more reference sounds from said collection of reference sounds according to predefined criteria; and c.4) as long as the sounds received from the environment match said one or more reference sounds from said collection of reference sounds, continuously pass the filtered sounds to said isolating headphones. a) storing a predefined collection of reference sounds in a database, these sounds include voices of friends of the user, their sound signatures or other sounds they produce; b) by said user, wearing sound isolating headphones, which are connected to his mobile phone; c) installing a mobile application on said mobile phone, said mobile application is adapted to: c.1) automatically activate a microphone of said mobile phone, when the isolating headphones are plugged into said mobile device; c.2) periodically compare in real-time, sounds received from the environment to said collection of reference sounds, wherein the sounds received from the environment consist of sounds received from the environment via said microphone and sounds received from a common friend regarding another friend that is nearby; c.3) selectively filter sounds out of the environment, which match one or more reference sounds from said collection of reference sounds according to predefined criteria, which includes selectively filter sounds out of the environment that are originated from friends of the user and which match one or more reference sounds from said collection of reference sounds according to predefined criteria; and c.4) as long as the sounds received from the environment match said one or more reference sounds from said collection of reference sounds, continuously pass the filtered sounds to said isolating headphones. c.1) automatically activate a microphone of said mobile phone, when the isolating headphones are plugged into said mobile device; c.2) periodically compare in real-time, sounds received from the environment to said collection of reference sounds, wherein the sounds received from the environment consist of sounds received from the environment via said microphone and sounds received from a common friend regarding another friend that is nearby; c.3) selectively filter sounds out of the environment, which match one or more reference sounds from said collection of reference sounds according to predefined criteria, which includes selectively filter sounds out of the environment that are originated from friends of the user and which match one or more reference sounds from said collection of reference sounds according to predefined criteria; and c.4) as long as the sounds received from the environment match said one or more reference sounds from said collection of reference sounds, continuously pass the filtered sounds to said isolating headphones.