Download Vowel Conversion by Phonetic Segmentation In this paper a system for vowel conversion between different speakers using short-time speech segments is presented. The input speech signal is segmented into period-length speech segments whose fundamental frequency and first two formants are used to find the perceivable vowel-quality. These segments are used to represent a voiced phoneme, i.e. a vowel. The approach relies on pitchsynchronous analysis and uses a modified PSOLA technique for concatenation of the vowel segments. Vowel conversion between speakers is achieved by exchanging the phonetic constituents of a source speaker’s speech waveform in voiced regions of speech whilst preserving prosodic features of the source speaker, thus introducing a method for phonetic segmentation, mapping, and reconstruction of vowels.
Download Improving Monophonic Pitch Detection Using the ACF And Simple Heuristics In this paper a study on the performance of the short time autocorrelation function for the determination of correct pitch candidates for non-stationary sounds is presented. Input segments of a music or speech signal are analyzed by extracting the autocorrelation function and a weighting function is used to weight candidates for assessing their harmonic strength. Furthermore, a decision is devised which alerts if there are possible non-related jumps on the fundamental frequency track. A technique to modify the spectral content of the signal is presented to compensate for these jumps, and a heuristic to return a steady fundamental frequency track for monophonic recordings is presented. The system is evaluated with several databases and with other algorithms. Using the compensation algorithm increases the performance of the ACF and outperforms current detection algorithms.