Approximants are speech sounds that involve the articulators approaching each other but not narrowly enough nor with enough articulatory precision to create turbulent airflow. Therefore, approximants fall between fricatives, which do produce a turbulent airstream, and vowels, which produce no turbulence. This class is composed of sounds like and semivowels like and, as well as lateral approximants like.
Breathy voice is a phonation in which the vocal folds vibrate, as they do in normal (modal) voicing, but are adjusted to let more air escape which produces a sighing-like sound. A simple breathy phonation,, can sometimes be heard as an allophone of English between vowels, such as in the word behind, for some speakers.
Phonetics is a branch of linguistics that studies how humans produce and perceive sounds or in the case of sign languages, the equivalent aspects of sign. Linguists who specialize in studying the physical properties of speech are phoneticians. The field of phonetics is traditionally divided into three sub-disciplines based on the research questions involved such as how humans plan and execute movements to produce speech, how various movements affect the properties of the resulting sound or how humans convert sound waves to linguistic information. Traditionally, the minimal linguistic unit of phonetics is the phone—a speech sound in a language which differs from the phonological unit of phoneme; the phoneme is an abstract categorization of phones and it is also defined as the smallest unit that discerns meaning between sounds in any given language.
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.
The field of articulatory phonetics is a subfield of phonetics that studies articulation and ways that humans produce speech. Articulatory phoneticians explain how humans produce speech sounds via the interaction of different physiological structures. Generally, articulatory phonetics is concerned with the transformation of aerodynamic energy into acoustic energy. Aerodynamic energy refers to the airflow through the vocal tract. Its potential form is air pressure; its kinetic form is the actual dynamic airflow. Acoustic energy is variation in the air pressure that can be represented as sound waves, which are then perceived by the human auditory system as sound.
Glottal consonants are consonants using the glottis as their primary articulation. Many phoneticians consider them, or at least the glottal fricative, to be transitional states of the glottis without a point of articulation as other consonants have, while some do not consider them to be consonants at all. However, glottal consonants behave as typical consonants in many languages. For example, in Literary Arabic, most words are formed from a root C-C-C consisting of three consonants, which are inserted into templates such as or. The glottal consonants and can occupy any of the three root consonant slots, just like "normal" consonants such as or.
The glottal stop or glottal plosive is a type of consonantal sound used in many spoken languages, produced by obstructing airflow in the vocal tract or, more precisely, the glottis. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ʔ⟩.
Pharyngealization is a secondary articulation of consonants or vowels by which the pharynx or epiglottis is constricted during the articulation of the sound.
The voiced alveolar fricatives are consonantal sounds. The symbol in the International Phonetic Alphabet that represents these sounds depends on whether a sibilant or non-sibilant fricative is being described.
The voiced bilabial fricative is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨β⟩, and the equivalent X-SAMPA symbol is B. The official symbol ⟨β⟩ is the Greek letter beta.
The voiced dental fricative is a consonant sound used in some spoken languages. It is familiar to English-speakers as the th sound in father. Its symbol in the International Phonetic Alphabet is eth, or and was taken from the Old English and Icelandic letter eth, which could stand for either a voiced or unvoiced (inter)dental non-sibilant fricative. Such fricatives are often called "interdental" because they are often produced with the tongue between the upper and lower teeth, and not just against the back of the upper teeth, as they are with other dental consonants.
The voiced retroflex plosive or stop is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ɖ ⟩, and the equivalent X-SAMPA symbol is d`. Like all the retroflex consonants, the IPA symbol is formed by adding a rightward-pointing hook extending from the bottom of a d, the letter that is used for the corresponding alveolar consonant. Many South Asian languages, such as Hindi and Urdu, have a two-way contrast between plain and murmured.
The voiced uvular fricative is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ʁ⟩, an inverted small uppercase letter ⟨ʀ⟩, or in broad transcription ⟨r⟩ if rhotic. This consonant is one of the several collectively called guttural R when found in European languages.
The voiceless glottal fricative, sometimes called voiceless glottal transition or the aspirate, is a type of sound used in some spoken languages that patterns like a fricative or approximant consonant phonologically, but often lacks the usual phonetic characteristics of a consonant. The symbol in the International Phonetic Alphabet that represents this sound is ⟨h⟩, and the equivalent X-SAMPA symbol is h. However, has been described as a voiceless vowel because in many languages, it lacks the place and manner of articulation of a prototypical consonant, as well as the height and backness of a prototypical vowel:
[h and ɦ] have been described as voiceless or breathy voiced counterparts of the vowels that follow them [but] the shape of the vocal tract [...] is often simply that of the surrounding sounds. [...] Accordingly, in such cases it is more appropriate to regard h and ɦ as segments that have only a laryngeal specification, and are unmarked for all other features. There are other languages [such as Hebrew and Arabic] which show a more definite displacement of the formant frequencies for h, suggesting it has a [glottal] constriction associated with its production.
The voiceless palatal fricative is a type of consonantal sound used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ç⟩, and the equivalent X-SAMPA symbol is C. It is the non-sibilant equivalent of the voiceless alveolo-palatal fricative.
In phonetics, the airstream mechanism is the method by which airflow is created in the vocal tract. Along with phonation and articulation, it is one of three main components of speech production. The airstream mechanism is mandatory for most sound production and constitutes the first part of this process, which is called initiation.
In phonetics, a trill is a consonantal sound produced by vibrations between the active articulator and passive articulator. Standard Spanish ⟨rr⟩ as in perro, for example, is an alveolar trill.
The (near) open front rounded vowel, or (near) low front rounded vowel, is a type of vowel sound that has not been confirmed to be phonemic in any spoken language. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ɶ⟩, and the equivalent X-SAMPA symbol is &. The letter ⟨ɶ⟩ is a small caps rendition of ⟨Œ⟩. ⟨œ⟩, the lowercase version of the ligature, is used for the open-mid front rounded vowel.
The term stiff voice describes the pronunciation of consonants or vowels with a glottal opening narrower, and the vocal folds stiffer, than occurs in modal voice. Although there is no specific IPA diacritic for stiff voice, the voicing diacritic may be used in conjunction with the symbol for a voiced consonant. In Bru, for example, stiff-voiced vowels have tenseness in the glottis and pharynx without going so far as to be creaky voiced, whereas slack-voiced vowels are lax in the glottis without going so far as to be breathy voice.
The voiceless alveolar fricatives are a type of fricative consonant pronounced with the tip or blade of the tongue against the alveolar ridge just behind the teeth. This refers to a class of sounds, not a single sound. There are at least six types with significant perceptual differences:
