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PSOLA
PSOLA (Pitch Synchronous Overlap and Add) is a digital signal processing technique used for speech processing and more specifically speech synthesis. It can be used to modify the pitch and duration of a speech signal. It was invented around 1986. PSOLA works by dividing the speech waveform in small overlapping segments. To change the pitch of the signal, the segments are moved further apart (to decrease the pitch) or closer together (to increase the pitch). To change the duration of the signal, the segments are then repeated multiple times (to increase the duration) or some are eliminated (to decrease the duration). The segments are then combined using the overlap add technique. PSOLA can be used to change the prosody of a speech signal. See also * Audio time stretching and pitch scaling Time stretching is the process of changing the speed or duration of an audio signal without affecting its pitch. Pitch scaling is the opposite: the process of changing the pitch without aff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speech Synthesis
Speech synthesis is the artificial production of human speech. A computer system used for this purpose is called a speech synthesizer, and can be implemented in software or hardware products. A text-to-speech (TTS) system converts normal language text into speech; other systems render symbolic linguistic representations like phonetic transcriptions into speech. The reverse process is speech recognition. Synthesized speech can be created by concatenating pieces of recorded speech that are stored in a database. Systems differ in the size of the stored speech units; a system that stores phones or diphones provides the largest output range, but may lack clarity. For specific usage domains, the storage of entire words or sentences allows for high-quality output. Alternatively, a synthesizer can incorporate a model of the vocal tract and other human voice characteristics to create a completely "synthetic" voice output. The quality of a speech synthesizer is judged by its similarity to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Time Stretching And Pitch Scaling
Time stretching is the process of changing the speed or duration of an audio signal without affecting its pitch. Pitch scaling is the opposite: the process of changing the pitch without affecting the speed. Pitch shift is pitch scaling implemented in an effects unit and intended for live performance. Pitch control is a simpler process which affects pitch and speed simultaneously by slowing down or speeding up a recording. These processes are often used to match the pitches and tempos of two pre-recorded clips for mixing when the clips cannot be reperformed or resampled. Time stretching is often used to adjust radio commercials and the audio of television advertisements to fit exactly into the 30 or 60 seconds available. It can be used to conform longer material to a designated time slot, such as a 1-hour broadcast. Resampling The simplest way to change the duration or pitch of an audio recording is to change the playback speed. For a digital audio recording, this can be accomp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal Processing
Signal processing is an electrical engineering subfield that focuses on analyzing, modifying and synthesizing ''signals'', such as audio signal processing, sound, image processing, images, and scientific measurements. Signal processing techniques are used to optimize transmissions, Data storage, digital storage efficiency, correcting distorted signals, subjective video quality and to also detect or pinpoint components of interest in a measured signal. History According to Alan V. Oppenheim and Ronald W. Schafer, the principles of signal processing can be found in the classical numerical analysis techniques of the 17th century. They further state that the digital refinement of these techniques can be found in the digital control systems of the 1940s and 1950s. In 1948, Claude Shannon wrote the influential paper "A Mathematical Theory of Communication" which was published in the Bell System Technical Journal. The paper laid the groundwork for later development of information c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speech Processing
Speech processing is the study of speech signals and the processing methods of signals. The signals are usually processed in a digital representation, so speech processing can be regarded as a special case of digital signal processing, applied to speech signals. Aspects of speech processing includes the acquisition, manipulation, storage, transfer and output of speech signals. The input is called speech recognition and the output is called speech synthesis. History Early attempts at speech processing and recognition were primarily focused on understanding a handful of simple phonetic elements such as vowels. In 1952, three researchers at Bell Labs, Stephen. Balashek, R. Biddulph, and K. H. Davis, developed a system that could recognize digits spoken by a single speaker. Pioneering works in field of speech recognition using analysis of its spectrum were reported in 1940s. Linear predictive coding (LPC), a speech processing algorithm, was first proposed by Fumitada Itakura of N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pitch (music)
Pitch is a perceptual property of sounds that allows their ordering on a frequency-related scale, or more commonly, pitch is the quality that makes it possible to judge sounds as "higher" and "lower" in the sense associated with musical melodies. Pitch is a major auditory attribute of musical tones, along with duration, loudness, and timbre. Pitch may be quantified as a frequency, but pitch is not a purely objective physical property; it is a subjective psychoacoustical attribute of sound. Historically, the study of pitch and pitch perception has been a central problem in psychoacoustics, and has been instrumental in forming and testing theories of sound representation, processing, and perception in the auditory system. Perception Pitch and frequency Pitch is an auditory sensation in which a listener assigns musical tones to relative positions on a musical scale based primarily on their perception of the frequency of vibration. Pitch is closely related to frequency, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duration (music)
In music, duration is an amount of time or how long or short a note, phrase, section, or composition lasts. "''Duration'' is the length of time a pitch, or tone, is sounded." A note may last less than a second, while a symphony may last more than an hour. One of the fundamental features of rhythm, or encompassing rhythm, duration is also central to meter and musical form. Release plays an important part in determining the timbre of a musical instrument and is affected by articulation. The concept of duration can be further broken down into those of beat and meter, where beat is seen as (usually, but certainly not always) a 'constant', and rhythm being longer, shorter or the same length as the beat. Pitch may even be considered a part of duration. In serial music the beginning of a note may be considered, or its duration may be (for example, is a 6 the note which begins at the sixth beat, or which lasts six beats?). Durations, and their beginnings and endings, may be describ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overlap Add
Overlap may refer to: * In set theory, an overlap of elements shared between sets is called an intersection, as in a Venn diagram. * In music theory, overlap is a synonym for reinterpretation of a chord at the boundary of two musical phrases * Overlap (railway signalling), the length of track beyond a stop signal that is proved to be clear of obstructions as a safety margin * Overlap (road), a place where multiple road numbers overlap * Overlap (term rewriting), in mathematics, computer science, and logic, a property of the reduction rules in term rewriting systems * Overlap add, an efficient convolution method using FFT * Overlap coefficient, a similarity measure between sets * Orbital overlap, important concept in quantum mechanics describing a type of orbital interaction that affects bond strength Overlapping can refer to: * "Reaching over", term in Schenkerian theory, see Schenkerian analysis#Lines between voices, reaching over See also * Overlay (other) Overlay may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prosody (linguistics)
In linguistics, prosody () is concerned with elements of speech that are not individual phonetic segments (vowels and consonants) but are properties of syllables and larger units of speech, including linguistic functions such as intonation, stress, and rhythm. Such elements are known as suprasegmentals. Prosody may reflect features of the speaker or the utterance: their emotional state; the form of utterance (statement, question, or command); the presence of irony or sarcasm; emphasis, contrast, and focus. It may reflect elements of language not encoded by grammar or choice of vocabulary. Attributes of prosody In the study of prosodic aspects of speech, it is usual to distinguish between auditory measures ( subjective impressions produced in the mind of the listener) and objective measures (physical properties of the sound wave and physiological characteristics of articulation that may be measured objectively). Auditory (subjective) and objective ( acoustic and articulatory) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
