Apparatuses and methods of transmitting and receiving a speech signal. The method of transmitting a speech signal includes extracting low frequency feature information from an input speech signal by using a first feature extracting network; and transmitting a speech signal corresponding to the low frequency feature information to a receiving end. The method of receiving a speech signal includes receiving a first speech signal transmitted by a transmitting end; extracting low frequency feature information from the first speech signal and recovering high frequency feature information based on the low frequency feature information, by using a second feature extracting network; and outputting a second speech signal including the low frequency feature information and the high frequency feature information.