Time-scale and pitch modi cations of speech signals and resynthesis from the discrete short-time Fourier transform
نویسندگان
چکیده
The modi cation methods described in this paper combine characteristics of PSOLA-based methods and algorithms that resynthesize speech from its short-time Fourier magnitude only. The starting point is a short-time Fourier representation of the signal. In the case of duration modi cation, portions, in voiced speech corresponding to pitch periods, are removed from or inserted in this representation. In the case of pitch modi cation, pitch periods are shortened or extended in this representation, and a number of pitch periods is inserted or removed, respectively. Since it is an important tool for both duration and pitch modi cation, the resynthesis-from-short-time-Fourier-magnitude-only method of Gri n and Lim, [4, 3], is reviewed and adapted. Duration and pitch modi cation methods and their results are presented. Zusammenfassung Die hier beschriebenen Variationsmethoden kombinieren Charakteristiken von PSOLA-basierten Methoden und Algorithmen zur Resynthetisierung von Sprache allein aus ihrem Kurzzeit-Fourier-Betragsspektrum. Der Ausgangspunkt ist eine Kurzzeit-Fourier-Repr asentation des Signals. Zur Dauermodi kation werden Signalst ucke ausgeschnitten, die bei stimmhafter Sprache den Pitchperioden entsprechen. Zur Pitchmodi kation werden die Pitchperioden verk urzt oder verl angert. Zum Dauerausgleich wird eine Anzahl Perioden hinzugef ugt oder weggelassen. Die "resynthesis-from-short-time-Fourier-magnitude-only"Methode von Gri n und Lim, [4, 3], wird besprochen und angepa t, da sie ein wichtiges Hilfsmittel sowohl zur Dauerals auch zur Pitchver anderung ist. Methoden zur Veranderung von Dauer und Pitch und die damit erzielten Ergebnisse werden dargestellt. R esum e Les m ethodes de modi cation d ecrites ici combinent des charact eristiques des m ethodes bas ees sur le principe PSOLA et des algorithmes pour resynth etiser la parole bas es uniquement sur le module de sa 3 transform ee de Fourier a court terme. Le point de d epart est une repr esentation de Fourier a court terme du signal. Pour e ectuer des modi cations de dur ee, des portions vois ees correspondant a des p eriodes compl etes sont supprim ees ou ins er ees. En ce qui concerne les modi cations de fr equence fondamentale, des p eriodes sont raccourcies ou ralong ees et un certain nombre de p eriodes respectivement supprim ees ou ins er ees. Comme il s'agit d'un outil important pour les modi cations de dur ee et de fr equence fondamentale, la m ethode de resynth ese de Gri n et Lim, [4, 3], bas ee uniquement sur le module de la transform ee de Fourier a court terme est revue et adapt ee. Des m ethodes de modi cation de dur ee et de fr equence fondamentale sont pr esent ees ainsi que leurs r esultats. 4
منابع مشابه
Time-scale and pitch modifications of speech signals and resynthesis from the discrete short-time Fourier transform
The modification methods described in this paper combine characteristics of PSOLA-based methods and algorithms that resynthesize speech from its short-time Fourier magnitude only. The starting point is a short-time Fourier representation of the signal. In the case of duration modification, portions, in voiced speech corresponding to pitch periods, are removed from or inserted in this representa...
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