A system and method for initiating conference calls with external devices are disclosed. Call participants are sent conference invitation and conference information regarding the designated conference call. This conference information is stored on the participant's external device. When the participants arrive at a conference call location having a conferencing device, the conferencing device is capable of communicating with the external device, initiating communications, exchanging conference information. If the participant is verified and/or authorized, the conference system may send the IP address of the conference device to the conference system to initiate the conference call. In one embodiment, the conference device uses an ultrasound acoustic communication band to initiate the call with the external device on a semi-automated basis. An acoustic signature comprising a pilot sequence for communications synchronization may be generated to facilitate the call. Audible and aesthetic acoustic protocols may also be employed.