speak·er·phone 
/ˈspi:kɚˌfoʊn/ noun
plural speak·er·phones /ˈspi:kɚˌfoʊn/ noun chiefly US : a feature on a telephone that allows you to talk and listen to someone without holding the receiver to your head [count] ▪ We used the speakerphone for the call so that everyone could hear what was said. [noncount] ▪ He put her on speakerphone so that everyone could hear what she said.
