Alveolar approximant

Alveolar approximant
ɹ
Image
IPA number	151
Encoding
Entity (decimal)	ɹ
Unicode (hex)	U+0279
X-SAMPA	r\
Kirshenbaum	r
Sound

The alveolar approximant is a type of consonantal sound used in some spoken languages. The symbol in the International Phonetic Alphabet that represents the alveolar and postalveolar approximants is ⟨ɹ⟩, a lowercase letter r rotated 180 degrees, or in broad transcription ⟨r⟩; the equivalent X-SAMPA symbol is ⟨r\⟩.

For ease of typesetting, English phonemic transcriptions often^{[citation needed]} use the symbol ⟨r⟩ instead of ⟨ɹ⟩, even though the former symbol technically represents the alveolar trill.

Features

Features of the alveolar approximant:

• Its manner of articulation is approximant, which means it is produced by narrowing the vocal tract at the place of articulation, but not enough to produce a turbulent airstream.
• Its place of articulation is alveolar, which means it is articulated with either the tip or the blade of the tongue at the alveolar ridge, termed respectively apical and laminal.
• Its phonation is voiced, which means the vocal cords vibrate during the articulation.
• It is an oral consonant, which means air is allowed to escape through the mouth only.
• It is a central consonant, which means it is produced by directing the airstream along the center of the tongue, rather than to the sides.
• The airstream mechanism is pulmonic, which means it is articulated by pushing air solely with the lungs and diaphragm, as in most sounds.

Articulatory properties of alveolar approximant

‘Voiced alveolar approximant’ is the standard description of /ɹ/ in American English. It is articulated with the tongue tip or blade placed closely to the region behind the teeth called the alveolar ridge. Some people claim that in their pronunciation of /ɹ/ the tip or blade of the tongue is placed behind the alveolar ridge and could, therefore, be characterized as post-alveolar.

Magnetic Resonance images of vocal tract configurations during /ɹ/ production show that speakers of American English employ a wide range of articulatory strategies and shape their tongue differently to produce /ɹ/. This may suggest that a great mastery of tongue muscles is required in order to reach the correct target for /ɹ/.

Auditory properties of alveolar approximant

The American English /ɹ/ displays a fairly stable pattern of the low third formant (F3) and the close proximity of the second and third formants (F2 and F3). The acoustic analysis of word-initial /ɹ/ done by closely inspecting spectrograms of words pronounced by children and adults has led many researchers to believe that the acoustic interaction between F2 and F3 is a primary cue in distinguishing /ɹ/ from other approximants /w/, /l/, and /j/, as well as labiodental /ʋ/ in speech perception.

Occurrence

Language		Word	IPA	Meaning	Notes
Armenian	Eastern	սուրճ	[suɹtʃʰ]	'coffee'
Chukchi		ңирэк	[ŋiɹek]	'two'
Dutch	Goois	door	[doəɹ]	'through'	Most dialects use an alveolar tap or trill. See Dutch phonology
	Leiden dialect	rat	[ɹat]	'rat'
English	American dialects	red	[ɹ̠ˤʷɛd]	'red'	Often retracted and labialized. In non-rhotic varieties, it occurs only before a vowel. May also be a labialized retroflex approximant; corresponds to an alveolar trill or alveolar tap in a few other dialects. For convenience it is often transcribed <r>. See English phonology
	Australian
	Received Pronunciation
Faroese		róður	[ɹɔuwʊɹ]	'rudder'
German	Westerwald	Rebe	[ɹeːbə]	'vine shoot'	Most other dialects use a voiced uvular fricative or uvular trill. See German phonology
	Siegerland
	Upper Lusatian
Igbo		karama	[kaɹama]	'bottle'
Portuguese	Many Central-Southern Brazilian dialects[citation needed]	verde	[ˈveɹdʒɪ]	'green'	Syllable-final allophone of rhotic consonant and also /l/. See Portuguese phonology
	Some countryside Central-Southern Brazilian dialects[citation needed]	temporal	[tẽjpoˈɾaɹ]	'rainstorm'
Spanish	Some dialects	doscientos	[do̞ɹˈθje̞nto̞s]	'two hundred'	Allophone of /s/ in the syllable coda. See Spanish phonology
Vietnamese		rơ	[ɹəː]	'to clean'	See Vietnamese phonology
Zapotec	Tilquiapan	rdɨ	[ɹd̪ɨ]	'pass'	Allophone of /ɾ/ before any consonant.

As an allophone of other rhotic sounds, /ɹ/ occurs in Edo, Fula, Murinh-patha, and Palauan.

Child acquisition

Typical developmental trajectory of feature

Research in phonological development references articulatory and acoustic descriptions. Children’s acquisition of consonants differs both in where and how the vocal tract is closed. Children lack control of their articulatory muscles due to the immaturity of their vocal tract structure. This could explain why the alveolar approximant is one of the last sounds mastered by children, approximately at the age of four. Acoustically, children’s pronunciations of /ɹ/ revealed higher frequencies for F2 and F3 formants, and a larger distance between them than those of adults.

Gliding

As children age, they develop a systematic way in which to adjust the sounds of their target language in order to fit within the range of sounds they can produce. These systematic transformations are called phonological processes. One phonological process typically found in child phonological acquisition is gliding – a segment substitution process involving the alveolar approximant. The gliding change is one in which sounds resembling /l/ and /ɹ/ which are traditionally classified as liquids are replaced by the sounds /j/ and /w/ which are traditionally classified as glides. For example, the alveolar approximant /ɹ/ is replaced with the liquid consonant /w/ so that ‘rabbit’ is pronounced as /wabɪt/ and /j/ replaces /l/ in ‘lamp’, and /w/ replaces /ɹ/ in ‘red’.

Difficulties in acquisition

The alveolar /ɹ/ is among the last of the phonemes to develop normally, and is also one of the most commonly misarticulated sounds due to its difficult pronunciation and similarities to other sounds. The nature of the sound’s production requires the speaker to manipulate different parts of the tongue, lips, and pharyngeal wall in relation to the palate making it more complex than most English sounds. In addition, the subtle contrast between /ɹ/ and /w/ may be difficult for children to differentiate in adult speech. As the English alveolar approximant sound has various contributing articulations that are not often audible or obvious, articulatory-delayed children and children with hearing loss often have difficulty acquiring it. In English, misarticulation is generally characterized by a high third formant and courses of treatment typically aim to lower the formant to normal levels. When a child misarticulates the alveolar approximant, they frequently substitute it for /w/, or distort it to a sound that falls somewhere between /ɹ/ and /w/. If difficulties articulating this approximant persist, an oral mechanism examination can be done to ensure the muscles of the mouth are working properly, and if they are and the errors are not caused by physiological limitations, the child might undergo articulation treatment. In the circumstance that misarticulation is caused by physiological abnormalities such as the Pierre Robin Sequence or banded lingual frenulum, treatment may rarely involve surgical intervention, but further therapeutic treatment is still necessary. In either case, a typical course of treatment involves having the child produce affected words while being instructed on the correct articulation of alveolar /ɹ/ for a speech language pathologist. Tasks designed to elicit use of the phoneme may involve the patient reading from a selected passage, verbally identifying objects in pictures, or producing spontaneous speech. Some errors that can be treated in therapeutic speech may remain present in spontaneous or informal speech, so the use of both reading and spontaneous tasks in therapy is imperative.

See also

• Alveolar lateral approximant
• Velarized alveolar approximant
• List of phonetic topics

References

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• Ball, M., Lowry, O., & McInnis, L. (2006), “Distributional and stylistic variation in /r/-misarticulations: A case study”. Clinical Linguistics & Phonetics, 20: 2-3.
• Boyce, S.; Espy-Wilson, C. (1997), "Coarticulatory stability in American English /r/", Journal of the Acoustical Society of America 101 (6): 3741–3753, DOI:10.1121/1.418333, PMID 9193061 
• Browman, L.; Goldstein (1995), "Gestural syllable position in American English", in Bell-Berti, F., Producing Speech: Contemporary issues for K Harris, New York: AIP, pp. 9–33 
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• Dalcher Villafaña, C., Knight, R.A., Jones, M.J., (2008), “Cue Switching in the Perception of Approximants: Evidence from Two English Dialects”. University of Pennsylvania Working Papers in Linguistics, 14 (2): 63-64.
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• Hallé, Pierre A.; Best, Catherine T.; Levitt, Andrea; Andrea (1999), "Phonetic vs. phonological influences on French listeners' perception of American English approximants", Journal of Phonetics 27 (3): 281–306, DOI:10.1006/jpho.1999.0097 
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• Merrill, Elizabeth (2008), "Tilquiapan Zapotec", Journal of the International Phonetic Association 38 (1): 107–114 
• Recasens, Daniel (2004), "The effect of syllable position on consonant reduction (evidence fromCatalan consonant clusters)", Journal of Phonetics 32 (3): 435–453, DOI:10.1016/j.wocn.2004.02.001 
• Sharf, D.J., Benson, P.J. (1982), “Identification of synthesized/r-w/continua for adult and child speakers”. Donald J. Acoustical Society of America, 71 (4):1008-1015.
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