Speech bandwidth extension method using speech recognition and speech synthesis

In this paper, we propose two kinds of novel speech bandwidth extension methods based on a speech recognition, a speech synthesis and a speech signal processing technique. In the proposed methods, the lost speech component by bandlimiting is generated with the technique of a speech recognition, a speech synthesis, and a speech signal processing by using the bandlimited speech information. For evaluating both proposed methods, we conducted the subjective and objective evaluation experiments. The experimental results shows the effectiveness of both proposed methods about the extension feeling of bandwidth. However, the evaluation of the speech quality became a not good result. Our problem is an improvement of the speech quality of the proposed method in the future.