An interesting variety of headphone styles is shown in this advertisement. The girl is holding the standard version originally adopted by the Telefon Hirmondó, where the two earpieces were not attached to each other, and thus could be separated so that two persons could each listen to a single earphone. The young woman is shown with an Electrophone-style receiver, which included a handle in the front so that the unit could be held in place. And "the busy man" is shown wearing headphones attached to a headband, a style most commonly associated with wireless operators.
"The Stentor" (this word choice emulates Telefon Hirmondó usage) or announcer is shown speaking into a characteristic dual-receiver, employed to collect as much sound as possible over a system with limited means to amplify signals.
Thanks to Craig Adams for providing the photocopies of this advertisement used to prepare this webpage.
Oregon Daily Journal, June 27, 1912, page 5 (a nearly identical advertisement appeared on page 2 of the June 26, 1912 Morning Oregonian):