A method for determining a measure for an attenuation provided by a hearing protector ear plug when worn by a user, said method comprises the performing of at least two measurements (2,3), wherein each of said at least two measurements comprises the steps of: - providing, by a computing device, a two channel test sound using a left audio channel and a right audio channel to a user via a headset; - receiving, by said computing device, a balance input signal, wherein said balance input signal relates to a perceived loudness of said left audio channel and a perceived loudness of said right audio channel of said two channel test sound by said user, and controlling, by said computing device, amplitudes of said left audio channel and said right audio channel of said two channel test sound provided to said user via said headset based on said received balance input signal; - receiving, by said computing device, an approval signal, wherein said approval signal indicates that said user perceives a same level of loudness of said left audio channel and said loudness of said right audio channel by an evoked binaural interaction; wherein a first of said at least two measurements is performed when said user is free from said hearing protector ear plug, and a second of said at least two measurements is performed when said user is wearing said hearing protector ear plug in one of its ears; wherein said method further comprises, after performing said at least two measurements (2,3), the step of: - determining said measure for said attenuation provided by said hearing protector ear plug based on said performed at least two measurements (2, 3); and wherein said two channel test sound to said user comprises a binaural audio test sound, wherein a sound that is provided to a left ear of the user is different from a sound that is provided to the right ear of the user, and wherein said binaural audio test sound is adapted to evoke a binaural interaction. - providing, by a computing device, a two channel test sound using a left audio channel and a right audio channel to a user via a headset; - receiving, by said computing device, a balance input signal, wherein said balance input signal relates to a perceived loudness of said left audio channel and a perceived loudness of said right audio channel of said two channel test sound by said user, and controlling, by said computing device, amplitudes of said left audio channel and said right audio channel of said two channel test sound provided to said user via said headset based on said received balance input signal; - receiving, by said computing device, an approval signal, wherein said approval signal indicates that said user perceives a same level of loudness of said left audio channel and said loudness of said right audio channel by an evoked binaural interaction; wherein a first of said at least two measurements is performed when said user is free from said hearing protector ear plug, and a second of said at least two measurements is performed when said user is wearing said hearing protector ear plug in one of its ears; wherein said method further comprises, after performing said at least two measurements (2,3), the step of: - determining said measure for said attenuation provided by said hearing protector ear plug based on said performed at least two measurements (2, 3); and - determining said measure for said attenuation provided by said hearing protector ear plug based on said performed at least two measurements (2, 3); and