This report describes a method of speech modification to improve the intelligibility of speech. The spectral energy is reallocated by maintaining and emphasizing acoustical features important for speech perception. The method consists of three components: flattening of the spectral tilt, enhancement of the spectral contrast, and holding of the low-frequency region. The results of this speech intelligibility test show that this method improves the speech intelligibility for all conditions of noise and SNR employed in the test.
Bibliographic reference. Takou, Reiko / Seiyama, Nobumasa / Imai, Atsushi (2013): "Improvement of speech intelligibility by reallocation of spectral energy", In INTERSPEECH-2013, 3605-3607.