Fast Inter-Harmonic Reconstruction for Spectral Envelope Estimation in High-Pitched Voices

During the production of voiced speech, the excitation signal performs a spectral subsampling of the filter transfer function. As a consequence, recovering the underlying spectral envelope (SE) becomes particularly difficult in high-pitched voices, where estimates using several conventional approaches are known to be contaminated by harmonics. To overcome such issues, this letter proposes to reconstruct inter-harmonics by a simple weigthed time-domain multiplication. Usual SE estimation methods can then be applied on the resulting signal. Both our objective and subjective experiments show that the proposed method provides similar or slightly better results when compared to more sophisticated approaches like true envelope or cubic spline interpolation between the harmonics. However, contrary to these latter techniques, its computational load is very low thanks to its simplicity.