  This paper proposes a time-domain method to improve speech intelligibility in
noisy scenarios. In the proposed approach, a series of Gammatone filters are
adopted to detect the harmonic components of speech. The filters outputs are
amplified to emphasize the first harmonics, reducing the masking effects of
acoustic noises. The proposed GTFF0 solution and two baseline techniques are
examined considering four background noises with different non-stationarity
degrees. Three intelligibility measures (ESTOI, ESII and ASIIST) are adopted
for objective evaluation. The experiments results show that the proposed scheme
leads to expressive speech intelligibility gain when compared to the competing
approaches. Furthermore, the PESQ and WSS objective scores demonstrate that the
proposed technique also provides interesting quality improvement.
