Functional load
Encyclopedia
In linguistics
and especially phonology
, functional load (also referred to as phonemic load) refers to the importance of certain features in making distinctions in a language. In other words, a high functional load wil make it hard to guess the identity of a phoneme in context when the phoneme has not been heard.
in 1929. Its most vocal advocate was André Martinet
, a historical linguist who claimed it was a factor in the likelihood of a phonological merger.
The first suggested measurement for functional load was the number of minimal pairs, but this does not take into account word frequency and is difficult to generalize beyond binary phonemic oppositions. Charles Hockett proposed an information theoretic
definition in 1955
, which has since been generalized. Now, given a large text corpus
, one can compute the functional load of any phonological contrast including distinctive feature
s, suprasegmentals, and distinctions between groups of phoneme
s. For instance, the functional load of tones in Standard Chinese
is as high as that of vowels i.e. the information lost when all tones sound alike is as much as that lost when all vowels sound alike.
Martinet predicted that perceptually similar pairs of phonemes with low functional load would merge. This has not been proved empirically; indeed, all empirical tests have come out against it e.g. /n/ merged with /l/ in Cantonese
in word-initial position in the late 20th century despite the fact that of all consonants in binary opposition to /n/, only the /n/-/m/ opposition had a higher functional load than the /n/-/l/ opposition.
s, for example, have a very high functional load. There are innumerable sets of words distinguished just
by their vowels, such as pin, pen, pan, pun, pain, pine. Voicing
is similar, as can be seen in pat - bad, sue - zoo. Speakers who do not control these differences make it very difficult for others to understand them.
However, although voicing is generally important in English, the voicing difference between the two fricatives written ‹th›, /θ, ð/, has a very low functional load: it is difficult to find meaningful distinctions dependent solely on this difference. One of the few examples is thigh vs. thy although the two can be distinguished from context alone. Similar is the difference of /dʒ/ (written ‹j›, ‹ge›, etc.) versus /ʒ/ (resulting from /z + j/, or the ‹j›, ‹ge›, etc. in some recent French
loanwords), as in virgin vs. version. The difference between the two ‹ng› sounds, [ŋ, ŋɡ], found in singer and finger, is so unimportant that it makes no practical difference if one mixes them up, and some dialects pronounce the sounds the same in both words. The functional load is nearly zero—-not surprising since the phoneme /ŋ/ originated as a coalescence of [ŋɡ] when word-final.
An ongoing example would be the merger of the AIR and EAR vowels in New Zealand English
. The phonetic similarity between words like here and hare does not seem to hamper oral communication in any major way as long as the context is provided. Therefore, those vowels have low functional load in New Zealand English despite their high frequency of occurrences in that dialect.
in Putonghua (Mandarin Chinese), which is as high as that of vowels. This means that the loss of information when all tones sound alike in Putonghua is approximately equal to that when all vowels sound alike in the language.
Linguistics
Linguistics is the scientific study of human language. Linguistics can be broadly broken into three categories or subfields of study: language form, language meaning, and language in context....
and especially phonology
Phonology
Phonology is, broadly speaking, the subdiscipline of linguistics concerned with the sounds of language. That is, it is the systematic use of sound to encode meaning in any spoken human language, or the field of linguistics studying this use...
, functional load (also referred to as phonemic load) refers to the importance of certain features in making distinctions in a language. In other words, a high functional load wil make it hard to guess the identity of a phoneme in context when the phoneme has not been heard.
Overview
The term "functional load" goes back to the days of the Prague School; references to it can be found in the work of Vilem MathesiusVilém Mathesius
Vilém Mathesius was a Czech linguist and literary historian, a scholar of English and Czech literature. His cousin was Bohumil Mathesius....
in 1929. Its most vocal advocate was André Martinet
André Martinet
André Martinet was a French linguist, influential by his work on structural linguistics....
, a historical linguist who claimed it was a factor in the likelihood of a phonological merger.
The first suggested measurement for functional load was the number of minimal pairs, but this does not take into account word frequency and is difficult to generalize beyond binary phonemic oppositions. Charles Hockett proposed an information theoretic
Information theory
Information theory is a branch of applied mathematics and electrical engineering involving the quantification of information. Information theory was developed by Claude E. Shannon to find fundamental limits on signal processing operations such as compressing data and on reliably storing and...
definition in 1955
, which has since been generalized. Now, given a large text corpus
Text corpus
In linguistics, a corpus or text corpus is a large and structured set of texts...
, one can compute the functional load of any phonological contrast including distinctive feature
Distinctive feature
In linguistics, a distinctive feature is the most basic unit of phonological structure that may be analyzed in phonological theory.Distinctive features are grouped into categories according to the natural classes of segments they describe: major class features, laryngeal features, manner features,...
s, suprasegmentals, and distinctions between groups of phoneme
Phoneme
In a language or dialect, a phoneme is the smallest segmental unit of sound employed to form meaningful contrasts between utterances....
s. For instance, the functional load of tones in Standard Chinese
Standard Chinese
Standard Chinese, or Modern Standard Chinese, also known as Mandarin or Putonghua, is the official language of the People's Republic of China and Republic of China , and is one of the four official languages of Singapore....
is as high as that of vowels i.e. the information lost when all tones sound alike is as much as that lost when all vowels sound alike.
Martinet predicted that perceptually similar pairs of phonemes with low functional load would merge. This has not been proved empirically; indeed, all empirical tests have come out against it e.g. /n/ merged with /l/ in Cantonese
Standard Cantonese
Cantonese, or Standard Cantonese, is a language that originated in the vicinity of Canton in southern China, and is often regarded as the prestige dialect of Yue Chinese....
in word-initial position in the late 20th century despite the fact that of all consonants in binary opposition to /n/, only the /n/-/m/ opposition had a higher functional load than the /n/-/l/ opposition.
English
English vowelVowel
In phonetics, a vowel is a sound in spoken language, such as English ah! or oh! , pronounced with an open vocal tract so that there is no build-up of air pressure at any point above the glottis. This contrasts with consonants, such as English sh! , where there is a constriction or closure at some...
s, for example, have a very high functional load. There are innumerable sets of words distinguished just
Minimal pair
In phonology, minimal pairs are pairs of words or phrases in a particular language, which differ in only one phonological element, such as a phone, phoneme, toneme or chroneme and have distinct meanings...
by their vowels, such as pin, pen, pan, pun, pain, pine. Voicing
Voice (phonetics)
Voice or voicing is a term used in phonetics and phonology to characterize speech sounds, with sounds described as either voiceless or voiced. The term, however, is used to refer to two separate concepts. Voicing can refer to the articulatory process in which the vocal cords vibrate...
is similar, as can be seen in pat - bad, sue - zoo. Speakers who do not control these differences make it very difficult for others to understand them.
However, although voicing is generally important in English, the voicing difference between the two fricatives written ‹th›, /θ, ð/, has a very low functional load: it is difficult to find meaningful distinctions dependent solely on this difference. One of the few examples is thigh vs. thy although the two can be distinguished from context alone. Similar is the difference of /dʒ/ (written ‹j›, ‹ge›, etc.) versus /ʒ/ (resulting from /z + j/, or the ‹j›, ‹ge›, etc. in some recent French
French language
French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...
loanwords), as in virgin vs. version. The difference between the two ‹ng› sounds, [ŋ, ŋɡ], found in singer and finger, is so unimportant that it makes no practical difference if one mixes them up, and some dialects pronounce the sounds the same in both words. The functional load is nearly zero—-not surprising since the phoneme /ŋ/ originated as a coalescence of [ŋɡ] when word-final.
An ongoing example would be the merger of the AIR and EAR vowels in New Zealand English
New Zealand English
New Zealand English is the dialect of the English language used in New Zealand.The English language was established in New Zealand by colonists during the 19th century. It is one of "the newest native-speaker variet[ies] of the English language in existence, a variety which has developed and...
. The phonetic similarity between words like here and hare does not seem to hamper oral communication in any major way as long as the context is provided. Therefore, those vowels have low functional load in New Zealand English despite their high frequency of occurrences in that dialect.
Mandarin
Another example is the functional load of toneTone (linguistics)
Tone is the use of pitch in language to distinguish lexical or grammatical meaning—that is, to distinguish or inflect words. All verbal languages use pitch to express emotional and other paralinguistic information, and to convey emphasis, contrast, and other such features in what is called...
in Putonghua (Mandarin Chinese), which is as high as that of vowels. This means that the loss of information when all tones sound alike in Putonghua is approximately equal to that when all vowels sound alike in the language.