Rhotic consonantIn phonetics, rhotic consonants, or "R-like" sounds, are liquid consonants that are traditionally represented orthographically by symbols derived from the Greek letter rho, including , in the Latin script and , in the Cyrillic script. They are transcribed in the International Phonetic Alphabet by upper- or lower-case variants of Roman , : r, ɾ, ɹ, ɻ, ʀ, ʁ, ɽ, and ɺ. Transcriptions for vocalic or semivocalic realisations of underlying rhotics include the ə and ɐ.
PerceptionPerception () is the organization, identification, and interpretation of sensory information in order to represent and understand the presented information or environment. All perception involves signals that go through the nervous system, which in turn result from physical or chemical stimulation of the sensory system. Vision involves light striking the retina of the eye; smell is mediated by odor molecules; and hearing involves pressure waves.
Occupational hearing lossOccupational hearing loss (OHL) is hearing loss that occurs as a result of occupational hazards, such as excessive noise and ototoxic chemicals. Noise is a common workplace hazard, and recognized as the risk factor for noise-induced hearing loss and tinnitus but it is not the only risk factor that can result in a work-related hearing loss. Also, noise-induced hearing loss can result from exposures that are not restricted to the occupational setting. OHL is a prevalent occupational concern in various work environments worldwide.
DiaphonemeA diaphoneme is an abstract phonological unit that identifies a correspondence between related sounds of two or more varieties of a language or language cluster. For example, some English varieties contrast the vowel of late (/eː/) with that of wait or eight (/ɛɪ/). Other English varieties contrast the vowel of late or wait (/eː/) with that of eight (/ɛɪ/). This non-overlapping pair of phonemes from two different varieties can be reconciled by positing three different diaphonemes: A first diaphoneme for words like late (⫽e⫽), a second diaphoneme for words like wait (⫽ei⫽), and a third diaphoneme for words like eight (⫽ex⫽).
Phone (phonetics)In phonetics and linguistics, a phone is any distinct speech sound or gesture, regardless of whether the exact sound is critical to the meanings of words. In contrast, a phoneme is a speech sound in a given language that, if swapped with another phoneme, could change one word to another. Phones are absolute and are not specific to any language, but phonemes can be discussed only in reference to specific languages. For example, the English words kid and kit end with two distinct phonemes, /d/ and /t/, and swapping one for the other would change one word into a different word.
Distinctive featureIn linguistics, a distinctive feature is the most basic unit of phonological structure that distinguishes one sound from another within a language. For example, the feature [voice] distinguishes the two bilabial plosives: [p] and [b]. There are many different ways of defining and arranging features into feature systems: some deal with only one language while others are developed to apply to all languages. Distinctive features are grouped into categories according to the natural classes of segments they describe: major class features, laryngeal features, manner features, and place features.
Specific language impairmentSpecific language impairment (SLI) (the term developmental language disorder is preferred by some) is diagnosed when a child's language does not develop normally and the difficulties cannot be accounted for by generally slow development, physical abnormality of the speech apparatus, autism spectrum disorder, apraxia, acquired brain damage or hearing loss. Twin studies have shown that it is under genetic influence. Although language impairment can result from a single-gene mutation, this is unusual.
Apraxia of speechApraxia of speech (AOS), also called verbal apraxia, is a speech sound disorder affecting an individual's ability to translate conscious speech plans into motor plans, which results in limited and difficult speech ability. By the definition of apraxia, AOS affects volitional (willful or purposeful) movement pattern. However, AOS usually also affects automatic speech. Individuals with AOS have difficulty connecting speech messages from the brain to the mouth.
GraphemeIn linguistics, a grapheme is the smallest functional unit of a writing system. The word grapheme is derived and the suffix -eme by analogy with phoneme and other names of emic units. The study of graphemes is called graphemics. The concept of graphemes is abstract and similar to the notion in computing of a character. By comparison, a specific shape that represents any particular grapheme in a given typeface is called a glyph. There are two main opposing grapheme concepts.
Lip readingLip reading, also known as speechreading, is a technique of understanding speech by visually interpreting the movements of the lips, face and tongue when normal sound is not available. It relies also on information provided by the context, knowledge of the language, and any residual hearing. Although lip reading is used most extensively by deaf and hard-of-hearing people, most people with normal hearing process some speech information from sight of the moving mouth.
