A

Acoustic Phonetics: The study of the sounds of speech through analysis of the acoustic waveform.

Acoustics: The study of the physical properties of sound.

Affricative: A composite speech sound consisting of a stop and a fricative articulated at the same point (as 'ch' in 'chair' and 'j' in 'joy').

Allophones: Variations on phones. Represent slight acoustic variations of the basic sound unit.

Alveolars: Sounds articulated with the tip of the tongue near the gum ridge (like /n/ in 'noon' and /t/ in 'time' and /r/ in 'run').

Annotation: Comments added in text to mark phrases and words so that the correct meaning is conveyed, for example the sentence "A Small Computer Company" can have two different meanings "A *small computer company*" meaning a computer company that is small and "A *small computer* company" meaning a company that makes small computers. The annotations here help resolve ambiguity for the natural language processor.

Approximants: Consonants produced in a manner similar to fricatives, but without friction, without making the airstream turbulent (like /y/ in 'yard').

Articulation: Bringing articulatory organs together so as to shape the sounds of speech. The process of expressing in coherent verbal form.

Articulators: The anatomical components that move to different positions to produce various speech sounds.

Articulatory Phonetics: The manner in which speech sounds are produced by the articulators of the vocal system.

Aspiration: The act of delaying the onset of voicing momentarily while exhaling air through a partially open glottis. The difference is heard in the phonemes /p/ as in 'spit' and the aspirated /p*/ as in 'pit.'

Audio: An audible acoustic wave frequency. The audible part of a transmitted signal.

Auditory: Of or relating to the process of hearing.

Auditory Phonetics: The study of the perceptual response to speech sounds as reflected in listener trials.

Audible Frequency Range of Hearing: The range of sound wave frequencies which a human ear is capable of detecting, it ranges between approximately 20 Hz to 20 000 Hz.

B

Bilabial: A consonant that is articulated using both lips; /p/ or /b/ or /w/.

C

Coarticulation: The interplay between sounds in an utterance. The preceding and or succeeding sound in a string can grossly affect a sound utterance. The change in phoneme articulation and acoustics caused by the influence of another sound in the same utterance.

Consonants: A speech sound that is not a vowel. They involve a significant restriction and are therefore weaker in amplitude and often "noisier" than vowels.

Continuant Consonant: Consonant articulated by constricting (but not closing) the vocal tract.

Continuant Phoneme: A phoneme is stationary or continuant if the speech sound is produced by a steady-state vocal-tract configuration.

Corpus: Collection of texts consisting of documents, dialogue transcriptions, translations and so forth. Collection of audio recordings along with their transcription. Collection of data for use in training/building a recognition, translation,... system.

D

Diacritical Mark: A mark added to a letter to indicate a special pronunciation.

Dictionary: Mapping of words and phrases in the two languages that are close in meaning. Translations of words and phrases from one language to the other.

Disambiguation: From many possible translations picking the one with minimum semantic distance.

Diphthong: A vowel sound that starts near the articulatory position for one vowel and moves toward the position for another (as /aI/ in 'buy' and /aU/ in 'how').

E

Egressive Sounds: Sounds produced when the air from the lungs is pushed through the trachea and pharynx and out through oral and/or nasal cavities.

Ejective Sounds: Sounds produced when only air in the oral cavity is pushed out.

Episodic Memory: Recollection of a particular event characterized by a definite awareness that the event was personally experienced.

F

Frequency: The number of occurrences within a given time period (usually 1 second). The frequency of a sound wave refers to how often the particles of the medium vibrate when a wave passes through the medium. The frequency of a sound wave is measured as the number of complete back-and-forth vibrations of a particle of the medium per unit of time.

Fricatives: A continuant consonant produced by breath moving against a narrowing of the vocal tract. Produced by forcing air through a constricted passage (as 'f'. 's', 'z', or 'th' (in both 'thin' and 'then')).

Formants/Formant Frequency: The nominal center frequencies of the resonances.

Fundamental Frequency of Phonation: The rate of vibration of the vocal folds.

Fundamental Period of Phonation: The time between successive vocal fold openings.

G

Generation Tree: A tree structure whose branches define the production rules as per the grammar and whose leaves are the sequence of words (in the new language). The generation tree is different from the parse tree in that the they are for different languages and hence follow different production rules and form different words.

Glide: A semivowel sound that serves as a consonant (like /w/ in 'wet' and /y/ in 'yeast'). Glides can be viewed as transient sounds as they maintain the target position for much less time than vowels.

Glottal: Consonants produced by the glottis (like /h/ in 'heat').

Glottis: The vocal apparatus of the larynx; the true vocal folds and the space between them where the voice tone is generated.

Grammar: Defines the production rules for the allowed sequence of words.

Grammar Writing: Writing grammar rules for natural language analysis.

H

Homographs: Two words are homographs if they are spelled the same way but differ in meaning (e.g. fair) or are different parts of speech (e. g. absent [verb] and absent [adjective]).

Homonyms: Words (like "write" and "right") that have the same pronunciation but different spellings.

I

Infrasound: Any sound with a frequency below the audible range of hearing (i.e., less than 20 Hz).

Ingressive Sounds: Sounds produced when the air is drawn into the vocal tract.

Interval: The difference in pitch between two notes. Certain sound waves when played (and heard) simultaneously will produce a particularly pleasant sensation when heard, are are said to be consonant. For example, any two sounds whose frequencies make a 2:1 ratio are said to be separated by an interval of an octave.

Intonation: The pitch contour over time. Rise and fall of the voice pitch.

J

K

L

Labial/Labial Consonant:A consonant whose articulation involves movement of the lips.

Labiodental: A consonant sound made by articulating with the lower lip against the upper teeth (like /f/ in 'fine' and /v/ in 'vine').

Language: A systematic means of communicating by the use of sounds or conventional symbols. The mental faculty or power of vocal communication.

Larynx: A cartilaginous structure at the top of the trachea; contains elastic vocal cords that are the source of the vocal tone in speech.

Lateral: Sounds in whose production the back of the tongue makes contact with the hard palate while the front of the tongue sinks down, channeling the air laterally around the tongue, down the side (or sometimes both sides) of the mouth (like /l/ in 'love').

Lexical: Of or relating to words.

Lexicon: A language user's knowledge of words. The sound patterns of words.

Linguistics: Consisting of or related to language. Of or relating to the scientific study of language. The scientific study of language and the manner in language rules are used in human communication.

Liquids: A semivowel that is usually much weaker than most vowels due to the more constricted vocal tract during their production. A frictionless non-nasal continuant (especially /l/ and /r/).

Longitudinal Wave: Are waves in which the motion of the individual particles of the medium is in a direction which is parallel to the direction of energy transport. A sound wave is a longitudinal wave.

M

Mechanical Wave: A disturbance which is transported through a medium via the mechanism of particle interaction. A sound wave is a mechanical wave. If the sound wave is moving through air, then as one air particle is displaced from its equilibrium position, it exerts a push or pull on its nearest neighbors, causing them to be displaced from their equilibrium position. This particle interaction continues throughout the entire medium, with each particle interacting and causing a disturbance of its nearest neighbors.

Medium: The medium is simply the material through which the disturbance is moving; it can be thought of as a series of interacting particles.

Morphology: The branch of grammar which studies the structure or forms of words. For example the knowledge that the word ringing is made up of ring plus ing.

N

Nasal: A continuant consonant produced through the nose with the mouth closed. For example /m, n, G/.

Noncontinuant Phoneme: A phoneme is noncontinuant if a change in the vocal-tract configuration is required during production of the speech sound.

O

Octave: Any two sounds whose frequencies make a 2:1 ratio are said to be separated by an octave and result in a particularly pleasing sensation when heard.

Orthographic Transcription: Spelling using the conventional alphabet of a language.

P

Palatal: A semivowel produced with the tongue near the palate (like the initial sound in the English word 'yeast').

Parse Tree: A tree structure whose branches define the production rules as per the grammar and whose leaves are the sequence of words (or phonemes).

Parsing: Obtaining the syntactic structure of a sentence by applying grammatical rules to it. The process of determining whether a set of production rules exists in a grammar for composing or decomposing a sentence.

Period: The interval taken to complete one cycle of a regularly repeating phenomenon. In the case of a sound wave the time interval of one complete back-and-forth vibration of a particle of the medium through which the sound wave is propagating.

Perplexity of the Grammer: The amount of constraint on the word choice.

Pharynx: The passage to the stomach and lungs; in the front part of the neck below the chin and above the collarbone.

Phonation: A sound produced by the larynx is called voice or phonation.

Phone: An individual sound unit of speech without concern as to whether or not it is a phoneme of some language. The actual sounds that are produced in speaking.

Phoneme: One of a small set of speech sounds that are distinguished by the speakers of a particular language. The phonemes of a language comprise a minimal theoretical set of units that are sufficient to convey all meaning in the language.

Phonemic: Of or relating to phonemes of a particular language. The study of the abstract units and their relationships in a language is called phonemics.

Phonemic Transcription: Translating some input form of the language - usually a speech waveform or an orthographic transcription - into a string of symbols representing the phonemes.

Phonetic Transcription: Translating some input form of the language - usually a speech waveform or an orthographic transcription - into a string of symbols which also includes diacritical marks on the phonemic symbols that indicate allophonic variations.

Phonetics: Of or relating to speech sounds. Of or relating to the scientific study of the actual speech sounds of the language. The science that studies the characteristics of human sound production, especially for the description, classification, and transcription of speech.

Phonology: The study of the variability in pronunciation of sounds of a given language.

Pitch: The sensations of various frequencies on the human auditory system are commonly referred to as the pitch of a sound. A high pitch sound corresponds to a high frequency and a low pitch sound corresponds to a low frequency.

Plosives: A consonant produced by stopping air at some point and suddenly releasing it. Produced by complete closure of the oral passage and subsequent release with a burst of air (as /p/ and /d/ in 'pit' or 'dog').

Pressure Wave: A wave consisting of a repeating pattern of high pressure and low pressure regions moving through a medium. A sound wave is a pressure wave.

Prosody: The tonal and rhythmic aspects of speech. Examples of prosodic features include, intonation and stress.

Pulmonic Sounds: Sounds produced by pushing air from the lungs out through the oral and/or nasal cavities.

Q

R

Resonance: One object vibrating at the same natural frequency of a second object that forces the second object into vibrational motion.

Retroflex: Sounds produced by curling the tongue tip back and articulating against the rear slope of the gum ridge (like the sound 'ada').

S

Schwa: A neutral middle vowel; occurs in unstressed syllables (the initial vowel in 'ahead' is a schwa vowel). It is a sort of "degenerate vowel" to which many others gravitate when articulated hastily in the course of flowing speech.

Semantics: The study of language meaning. The meaning of the words and sentences in a language.

Semitone: The musical interval between adjacent keys on a keyboard instrument.

Semivowel: A vowel-like sound that serves as a consonant (/w/, /l/, /r/ and /y/).

Semantic: Of or relating to the study of meaning and changes of meaning.

Semantic Distance Calculation: (a) Calculating the semantic distance between words based on their meaning: (b) calculating the similarity or closeness of the meaning between words.

Semantic Network: Schematic representation of knowledge that takes the form of a network. Network nodes represent concepts, and links represent the relationship between concepts.

Senone: An equivalence class which models a subphonetic event usually one state in a HMM for a phoneme. (Different phone models can share the same senone if they exhibit acoustic similarity)

Sound: The subjective sensation of hearing something. It is an individual sound unit of speech without concern as to whether or not it is a phoneme of some language.

Sound Wave: A wave that transmits sound. Sound is a mechanical wave which results from the longitudinal motion of the particles of the medium through which the sound wave is moving. If a sound wave is moving from left to right through air, then particles of air will be displaced both rightward and leftward as the energy of the sound wave passes through it. The motion of the particles parallel (and anti-parallel) to the direction of the energy transport is what characterizes sound as a longitudinal wave.

Speech: The sound perceived by the auditory system.

Spirants: Spirants involve the same restriction of the speech canal as fricatives, but the speech organs are substantially less tense during the articulation of a spirant. Rather than friction, a resonant sound is produced at the place of articulation (as /th/ and /dh/ in 'thing' and 'then').

Stress: Refers to a change in fundamental frequency and loudness to signify a change in emphasis of a syllable, word or phrase.

Stops: A consonant produced by stopping air at some point and suddenly releasing it. Produced by complete closure of the oral passage and subsequent release with a burst of air (as /p/ and /d/ in 'pit' or 'dog').

Suprasegmental: Pertaining to a feature of speech that extends over more than a single speech sound.

Syllable: A unit of spoken language larger than a phoneme.

Syntax: The grammatical structure of the language.

T

Tap: A class of vibrants. Voiced sound produced with a single vibration of one articulator against another, for example the phoneme /r/ in 'range.'

Tone: A pitch or change in pitch of the voice that serves to distinguish words in tonal languages.

Third: Two sounds with a frequency ratio of 5:4 are said to be separated by an interval of a third.

Translation: Rendering into another language.

Trill: A note that alternates rapidly with another note a semitone above it. A class of vibrants. Voiced sound produced by the repeated vibration of one articulator against another, for example the 'the rolled /r/' in 'trill.'

U

Ultrasound: Any frequency above the audible range of hearing (i.e., more than 20 000 Hz).

Unvoiced Sounds: Sounds that are generated by forming a constriction at some point along the vocal tract, and forcing air through the constriction to produce turbulence. An example is the /s/ sound in 'six.'

Uvular: Sound produced with the extreme back of the tongue against the uvula (like /q/ in 'quick').

V

Velar: Sound produced with the back of the tongue touching or near the soft palate (velum) (as /k/ in 'cat' and /g/ in 'gun' and /ng/ in 'sing').

Voice: A process of producing sound by the human speech production system. The sound produced by the larynx.

Voiced Sounds: Sounds produced by forcing air through the glottis or an opening between the vocal folds. An example is the /I/ sound in 'six.'

Vowels: A speech sound made with the vocal tract open. Their production involves no major airflow restriction through the vocal tract (as /a/ in 'cat').

Vibrants: Consonants that involve one or more tapping or flapping vibrations of the speech organs under pressure from the airstream. Part of the tongue makes contact with the palate, most commonly at the alveolar ridge, the soft palate, or the uvula. One or more very brief occlusions occur successively, accompanied by short resonances. Vibrants are generally voiced.

W

Wave: A disturbance that travels through a medium, transporting energy from one location to another location. It is a progressive disturbance propagated without displacement of the medium itself.

X

Y

Z