Beyond NYQUIST: towards the recovery of broad-bandwidth speech from narrow-bandwidth speech
Carlos Avendaño, Hynek Heřmanský, Eric A. Wan · 1995
A new technique is presented which improves the subjective quality of band-limited speech. The approach is based on a linear model of speech production, in which we independently estimate the spectral envelope and excitation function for a broad-bandwidth speech signal to reconstruct missing frequency components in narrow-bandwidth speech.