In speech science and phonetics, a formant is the broad spectral maximum that results from an acoustic resonance of the human vocal tract. In acoustics, a formant is usually defined as a broad peak, or local maximum, in the spectrum. For harmonic sounds, with this definition, the formant frequency is sometimes taken as that of the harmonic that is most augmented by a resonance. The difference between these two definitions resides in whether "formants" characterise the production mechanisms of a sound or the produced sound itself. In practice, the frequency of a spectral peak differs slightly from the associated resonance frequency, except when, by luck, harmonics are aligned with the resonance frequency.
A harmonic series is the sequence of frequencies, musical tones, or pure tones in which each frequency is an integer multiple of a fundamental.
The term phonation has slightly different meanings depending on the subfield of phonetics. Among some phoneticians, phonation is the process by which the vocal folds produce certain sounds through quasi-periodic vibration. This is the definition used among those who study laryngeal anatomy and physiology and speech production in general. Phoneticians in other subfields, such as linguistic phonetics, call this process voicing, and use the term phonation to refer to any oscillatory state of any part of the larynx that modifies the airstream, of which voicing is just one example. Voiceless and supra-glottal phonations are included under this definition.
Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies from person to person and is approximately 20 kilohertz in healthy young adults. Ultrasound devices operate with frequencies from 20 kHz up to several gigahertz.
A vowel is a syllabic speech sound pronounced without any stricture in the vocal tract. Vowels are one of the two principal classes of speech sounds, the other being the consonant. Vowels vary in quality, in loudness and also in quantity (length). They are usually voiced and are closely involved in prosodic variation such as tone, intonation and stress.
Linear predictive coding (LPC) is a method used mostly in audio signal processing and speech processing for representing the spectral envelope of a digital signal of speech in compressed form, using the information of a linear predictive model.
An overtone is any frequency greater than the fundamental frequency of a sound. In other words, overtones are all pitches higher than the lowest pitch within an individual sound; the fundamental is the lowest pitch. While the fundamental is usually heard most prominently, overtones are actually present in any pitch except a true sine wave. The relative volume or amplitude of various overtone partials is one of the key identifying features of timbre, or the individual characteristic of a sound.
Speech synthesis is the artificial production of human speech. A computer system used for this purpose is called a speech computer or 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.
Dida is a dialect cluster of the Kru family spoken in Ivory Coast.
In music, timbre, also known as tone color or tone quality, is the perceived sound quality of a musical note, sound or tone. Timbre distinguishes different types of sound production, such as choir voices and musical instruments. It also enables listeners to distinguish different instruments in the same category.
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.
In sound processing, the mel-frequency cepstrum (MFC) is a representation of the short-term power spectrum of a sound, based on a linear cosine transform of a log power spectrum on a nonlinear mel scale of frequency.
Silbo Gomero, also known as el silbo, is a whistled register of Spanish used by inhabitants of La Gomera in the Canary Islands to communicate across the deep ravines and narrow valleys that radiate through the island. It enables messages to be exchanged over a distance of up to 5 kilometres. Due to its loud nature, Silbo Gomero is generally used in circumstances of public communication. Messages conveyed could range from event invitations to public information advisories. A speaker of Silbo Gomero is sometimes referred to in Spanish as a silbador ('whistler'). Silbo Gomero is a transposition of Spanish from speech to whistling. This oral phoneme-whistled phoneme substitution emulates Spanish phonology through a reduced set of whistled phonemes. It was declared as a Masterpiece of the Oral and Intangible Heritage of Humanity by UNESCO in 2009.
Acoustic phonetics is a subfield of phonetics, which deals with acoustic aspects of speech sounds. Acoustic phonetics investigates time domain features such as the mean squared amplitude of a waveform, its duration, its fundamental frequency, or frequency domain features such as the frequency spectrum, or even combined spectrotemporal features and the relationship of these properties to other branches of phonetics, and to abstract linguistic concepts such as phonemes, phrases, or utterances.
The open-mid central rounded vowel, or low-mid central rounded vowel, is a vowel sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ɞ⟩, and the equivalent X-SAMPA symbol is 3\. The symbol is called closed reversed epsilon. It was added to the IPA in 1993; before that, this vowel was transcribed ⟨ɔ̈⟩.
Signal processing is an electrical engineering subfield that focuses on analysing, modifying, and synthesizing signals such as sound, images, and scientific measurements. For example, with a filter g, an inverse filterh is one such that the sequence of applying g then h to a signal results in the original signal. Software or electronic inverse filters are often used to compensate for the effect of unwanted environmental filtering of signals.
Kenneth Noble Stevens was the Clarence J. LeBel Professor of Electrical Engineering and Computer Science, and Professor of Health Sciences and Technology at the Research Laboratory of Electronics at MIT. Stevens was head of the Speech Communication Group in MIT's Research Laboratory of Electronics (RLE), and was one of the world's leading scientists in acoustic phonetics.
A vowel diagram or vowel chart is a schematic arrangement of the vowels. Depending on the particular language being discussed, it can take the form of a triangle or a quadrilateral. Vertical position on the diagram denotes the vowel closeness, with close vowels at the top of the diagram, and horizontal position denotes the vowel backness, with front vowels at the left of the diagram. Vowels are unique in that their main features do not contain differences in voicing, manner, or place (articulators). Vowels differ only in the position of the tongue when voiced. The tongue moves vertically and horizontally within the oral cavity. Vowels are produced with at least a part of their vocal tract obstructed.
The standard pronunciation of Cantonese is that of Guangzhou, also known as Canton, the capital of Guangdong Province. Hong Kong Cantonese is related to the Guangzhou dialect, and the two diverge only slightly. Yue dialects in other parts of Guangdong and Guangxi provinces, such as Taishanese, may be considered divergent to a greater degree.
The quantal theory of speech is a phonetic answer to one of the fundamental questions of phonology, specifically: if each language community is free to arbitrarily select a system of phonemes or segments, then why are the phoneme inventories of different languages so similar? For example, almost all languages have the stop consonants /p/, /t/, /k/, and almost all have the vowels /a/, /i/, and /u/. Other phonemes differ considerably among languages, but not nearly as much as they would if each language were free to choose arbitrarily.
