Phoneme

A phoneme is a unit of natural language that can help distinguish one word from another as different meaningful units, such as /b/ versus /m/ in English bat and mat. It is often considered the smallest unit of language that can serve that distinguishing purpose, but others have been proposed. It is of interest in the subfield of linguistics called phonology. The English language is generally considered to have around 45 phonemes, but there is not full agreement about that number. Indeed it varies between different varieties of English.

In spoken language, phonemes are regarded as the individual 'sounds' of the language, corresponding very roughly to the sounds of the letters of an alphabet—though a phoneme may also be in fact a small group of consecutive sounds.

The concept of the phoneme is used in understanding sign languages as well.

Limitations

The existence of phonemes is generally assumed in many fields of linguistics and education, but phonemes been rejected as a true unit of analysis in mainstream phonology since the publication of Chomsky and Halle's The Sound Pattern of English in 1968. The problem is, that meaning is often also inferred from context, so phonemes alone may not provide enough distinguishing information. Some tonal languages, for example, have units of meaning that depend on both tone and alphabet; yet written versions of the language may lack a notation for how people use tonality. That tends to be okay, because context may provides enough additional information for the hearers of tonal language to understand which of various possible intonation-distinguished meanings was intended.

The importance of context for phonemes was arguably proven well before Chomsky and Halle's study, due to the work of missionary John F. Carrington, the first European to realize how the "talking drums" in Africa could be used to communicate sophisticated messages (based on several African languages) over long distances, although they lacked the ability to articulate any vowel or consonant. Drummers used a combination of rhythm and tonality to suggest words to listeners, dependent on context. This was possible because of the importance of rhythm and tonality in the African languages behind the drumming. Carrington published a book about the talking drums in the 1940's. Although the spoken languages used by the drummers also had consonant and vowel-based "phonemes", the vowels and consonants proved unnecessary for the transmission of simple messages, even including (sometimes) jokes.

Phonemes and other phonological segments

Phonemes are not the smallest level of sound classification. The sound inventory of a language is the set of phones of that language. However, phones do not distinguish meaning in themselves. What makes a phoneme a phoneme, rather than a phone, is that changing it to another phoneme may yield a different word. For instance, /mat/ ("mat") and /mad/ ("mad") are different words in English. They are distinguished by only one different phoneme: /t/ versus /d/ (put more specifically, it is the opposition between voiceless and a voiced dental plosive in the first versus the second word). This difference is called phonemic. In addition, word pairs such as "bat/mat" or "mat/mad" in English are called minimal pairs, because they are only distinguished by one phoneme.

On the other hand, the phoneme /t/ can be pronounced as one of several distinct phones ([t] (unaspirated) and [t^h] (aspirated t)), called the allophones of /t/. The choice of allophone depends on the context surrounding the /t/ and the phonological rules in the language ([t^h], for example, occurs initially in English stressed syllables, e.g. [ə.t^hæk] attack). As a result, changing between allophones (such as saying [tom] vs [t^hom]) would not yield a new word, as above, but instead would be a violation of the phonological constraints (phonotactics) of the language.

Experiments

The way individual phonemes are recognized in human speech can be examined by means of non-existing syllables which consist nevertheless of real phonemes, so-called logatomes.

See also

• Phonology
• Phonetics