1. A speech aid system comprising: a tube configured for mounting at a tracheostomy of a user; a voice parameter acquiring device mounted to said tube, and configured to sense airflow applied within said tube resulting from attempt by the user to speak, and to generate a voice parameter signal according to the airflow sensed thereby; a processor configured to receive the voice parameter signal from said voice parameter acquiring device, and to generate an audio signal corresponding to the voice parameter signal; and a sound generator configured for mounting in an oral cavity of the user, configured to receive the audio signal from said processor, and configured to produce a substitute glottal sound corresponding to the audio signal.