A mobile wireless communications device includes a housing and transceiver carried by the housing for transmitting and receiving radio frequency (RF) signals carrying communications data of speech. A processor is coupled to the transceiver for processing the communications data as speech that is transmitted and received to and from the transceiver. A keyboard and display is carried by the housing and connected to the processor. A speech-to-text and text-to-speech module converts communications data as speech received from the transceiver to text that is displayed on the display and converting text that is typed by a user on the keyboard in the communications data as speech to be transmitted from the transceiver as an RF signal.