Telephone network speech signal enhancement

Claim 1

A method of enhancing the quality of speech signals exchanged between first (S1) and second (S2) telephone station sets, said method comprising the steps of responding to receipt of a request originated by either one of said first or second telephone station sets by establishing a communication path between said first and second telephone station sets, wherein at least one of said first and second telephone station sets is arranged to attenuate by a predetermined attenuation rate those of said speech signals having frequencies below a predetermined frequency and to transmit said speech signals over said communications path, and CHARACTERISED BY responding to receipt of said speech signals transmitted by said one of said first and second telephone station sets by increasing by a predetermined level said attenuated speech signals and then supplying to the other one of said first and second telephone station sets via said communication path the resulting speech signals.