Perfect for Guided Tours which incorporate a talk-back feature for tour participants, patented "Open Guided Sound" (OGS) binaural earphones provide high fidelity sound without obscuring or occluding the sounds of the surrounding environment like convention bulky headphones or earbuds. Visit Montmartre...hear the tourguide talk about the impressionist painters and Toulouse Lautrec's exploits in Pigalle...hear the scooter zipping up behind you so you can dodge at the last moment. Experience it all....Vive la France. Hear your own voice when speaking VoIP rather than the congested sensation you get with Bluetooth and closed earphones that block awareness of your own voice and speaking level.