... Atelephoneconferencewherethreeormoreparticipantsshareinaconversation.Confer-encecallbuttonsorcodesareavailableonsomelo-calmultilinesystems,andoperatorscansetupcon-ferencecallsacrosspubliclinesforparticipantswhoaredistantfromoneanother.Seevideoconference.telecopierSeefacsimilemachine.914teledensity ... handset,headset,orspeakerphonewhichconvertssoundintoelectricalimpulses.Onatraditionalhandset,there-ceivercircuitconnectstothe part thatyouholdnexttoyourmouth.Insidethemouthpieceisamovablediaphragmwithanattachedcarbonelectrode,behindwhichanothercarbonelectrodeisfastenedsecurelyinsidethehousing.Betweentheelectrodesarecar-bongranules(it'spossibletobuildasimplephonetransmitterusingthecoreofacarbonpencil ... mechanicalswitchin~stationsstillexist,updatedswitchboardsfunctionelectronically.telephone tagColloquialphrasefortwopartiesat-temptingtocontactoneanotherbyphone,notreachingtheother person,andleaving...