This document discusses the history and methods of speech synthesis. It notes that the first speech synthesizer was created in 1791 and was able to produce 19 consonants and 5 vowels by modulating the vibration of reeds through a leather tube. There are three main methods of speech synthesis: waveform coding, analysis-synthesis, and synthesis by rule. Waveform coding involves storing recorded speech waves and selecting/connecting units to synthesize speech. Analysis-synthesis breaks sounds down into parameters and rules for re-synthesis. Synthesis by rule generates new waves without human recordings. Modern methods like TD-PSOLA and the Harmonic/Noise Model divide the speech spectrum and concatenate frames to alter prosody.

1. Speech synthesis
by Aveen M

2. Principles of speech synthesis
• Speech synthesis is a process which artificially
produces speech for various application.
• Anybody can easily understand.
• Paper free.

3. Cont..
• First speech synthesizer is constructed in 1791.
• This synthesizer, capable of producing both
vowels and consonants.
• Sounds originating through the vibration of reeds
were modulated by the resonance of a leather
tube and radiated as a speech wave.
• Able to produce 19 consonants and 5 vowels.

4. Mechanical speech synthesizer by von kempelen

7. Three speech synthesis methods
• Waveform coding.
• Analysis-synthesis.
• Synthesis by rule.

10. Synthesis based on waveform coding
• In which speech waves of recorded human voice stored
after waveform coding are used to produce speech.
• Speech is synthesis by selecting and connecting the
appropriate units.
• Store variations of the same words with rising, flat and
falling inflections.
• Pitch synchronous method is used.

11. Time domain pitch synchronous
overlap add
• The TD-PSOLA is a concatenation method.
• This method relies on the speech production model described by
the sinusoidal framework.
• The analysis part consists of extracting short-time analysis signals
by multiplying the speech waveform by a sequence of time-
translated analysis windows.
• The analysis windows are located around glottal closure instants
and their length is proportional to the local pitch period.
• Mapping specifies which of the short-time analysis signal will be
eliminated.

12. Harmonic pulse noise model
• Spectrum is divided into two bands, with lowband
being represented by harmonically.
• The noise part ,n(t) is obtained by filtering.
• Time-varying parameter referred to as maximum
voiced frequency determines the limit.
• Synthesis time HNM frames are concatenated and the
prosody of units is altered according to the desired
prosody.

13. Thank you