Ahocoder parameterizes speech waveforms into three different streams: log-f0, cepstral representation of the spectral envelope, and maximum voiced frequency. It provides high accuracy during analysis and high quality during reconstruction. It is adequate for statistical parametric speech synthesis and voice conversion. Furthermore, it can be used just for basic speech manipulation and transformation (pitch level and variance, speaking rate, vocal tract length...).

Ahocoder is reported to be a very good complement for HTS. The output files generated by Ahocoder contain float numbers without header, so they are fully compatible with the HTS demo scripts in the HTS website. You can use the same configuration as in the STRAIGHT-based demo, using the "bap" stream to handle maximum voiced frequency (set its dimension to 1 both in data/Makefile and in scripts/Config.pm).

For more technical details, please have a look to these related publications:

• D. Erro, I. Sainz, E. Navas, I. Hernaez, "Harmonics plus Noise Model based Vocoder for Statistical Parametric Speech Synthesis", IEEE J. Sel. Topics in Signal Process., vol. 8(2), pp. 184-194, 2014.
• D. Erro, I. Sainz, E. Navas, I. Hernaez, "Efficient Spectral Envelope Estimation from Harmonic Speech Signals", IET Electronics Letters, vol. 48(16), pp. 1019-1021, 2012.
• D. Erro, I. Sainz, E. Navas, I. Hernaez, "Improved HNM-based Vocoder for Statistical Synthesizers", InterSpeech, pp. 1809-1812, Florence, August 2011.
• D. Erro, I. Sainz, E. Navas, I. Hernaez, "HNM-based MFCC+F0 Extractor applied to Statistical Speech Synthesis", IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), pp. 4728-4731, Prague, May 2011.
• D. Erro, I. Sainz, I. Saratxaga, E. Navas, I. Hernaez, "MFCC+F0 extraction and waveform reconstruction using HNM: preliminary results in an HMM-based synthesizer", VI Jornadas en Tecnologia del Habla & II Iberian SLTech (FALA), pp. 29-32, Vigo, November 2010.

Through this website you can get an executable version of the tool. For any doubt, suggestion, comment, feedback, etc, please contact the main author D. Erro: derro(a)aholab.ehu.es

AHOLAB Signal Processing Laboratory, UPV/EHU.

Alda. Urquijo s/n, 48013 Bilbao, Spain. Phone: +34 946017245. Fax: +34 946014259.
Contact email: derro(a)aholab.ehu.es