Development, evaluation and implementation of an artificial bandwidth extension method of telephone speech in mobile terminal

Artificial bandwidth extension methods aim to improve the quality and intelligibility of narrowband telephone speech by adding new, artificially generated spectral content to the highband of the received voice signal. The development cycle of an artificial bandwidth extension method from the initial idea to the implementation in a mobile terminal is discussed in this paper. Developing the algorithm in the Matlab environment was the first step in the process. The method was then evaluated in formal listening tests and simulations to verify its performance in different scenarios. Finally, the utilization of this technology in a product included its DSP implementation combined with the acoustical design of the user terminal.