headphones were mainly used for communication purposes headphones were mainly used for communication purposes headphones headphones were mainly used for communication purposes sfârșitul secolului al XIX-lea catch the full article on their site. headphones were mainly used for communication purposes "The History of Headphones | Cool Material" headphones headphones were mainly used for communication purposes desde 1881 The History of Headphones headphones were mainly used for communication purposes historii sluchátek The History of Headphones headphones were mainly used for communication purposes The History of Headphones headphones were mainly used for communication purposes