Voiceless dental fricative

The voiceless dental non-sibilant fricative is a type of consonantal sound used in some oral languages. It is familiar to English speakers as the 'th' in thing. Though rather rare as a phoneme in the world's inventory of languages, it is encountered in some of the most widespread and influential (see below). The symbol in the International Phonetic Alphabet that represents this sound is ⟨θ⟩, and the equivalent X-SAMPA symbol is T. The IPA symbol is the Greek letter theta, which is used for this sound in post-classical Greek, and the sound is thus often referred to as "theta".

The dental non-sibilant 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 or lower teeth, as they are with other dental consonants.

Among the more than 60 languages with over 10 million speakers, only English, Modern Standard Arabic, Standard European Spanish, Burmese, and Greek have the voiceless dental non-sibilant fricative. Speakers of languages and dialects without the sound sometimes have difficulty producing or distinguishing it from similar sounds, especially if they have had no chance to acquire it in childhood, and typically replace it with a voiceless alveolar fricative (/s/), voiceless dental stop (/t/), or a voiceless labiodental fricative (/f/; known respectively as th-alveolarization, th-stopping, and th-fronting).

Dental fricative

The dental fricative or interdental fricative is a fricative consonant pronounced with the tip of the tongue against the teeth. There are several types (those used in English being written as th):

Phonetic alphabet

Phonetic alphabet can mean:

International Phonetic Alphabet

The International Phonetic Alphabet (unofficially—though commonly—abbreviated IPA) is an alphabetic system of phonetic notation based primarily on the Latin alphabet. It was devised by the International Phonetic Association as a standardized representation of the sounds of oral language. The IPA is used by lexicographers, foreign language students and teachers, linguists, speech-language pathologists, singers, actors, constructed language creators, and translators.

The IPA is designed to represent only those qualities of speech that are part of oral language: phones, phonemes, intonation, and the separation of words and syllables. To represent additional qualities of speech, such as tooth gnashing, lisping, and sounds made with a cleft palate, an extended set of symbols called the Extensions to the International Phonetic Alphabet may be used.

IPA symbols are composed of one or more elements of two basic types, letters and diacritics. For example, the sound of the English letter ⟨t⟩ may be transcribed in IPA with a single letter, [t], or with a letter plus diacritics, [t̺ʰ], depending on how precise one wishes to be. Often, slashes are used to signal broad or phonemic transcription; thus, /t/ is less specific than, and could refer to, either [t̺ʰ] or [t], depending on the context and language.