غلت سختکامی /j/ در نظام آوایی زبان فارسی

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشیار گروه زبان شناسی، دانشگاه بین المللی امام خمینی(ره)

2 دانش آموخته‏ ی کارشناسی ارشد زبان شناسی همگانی، دانشگاه بین المللی امام خمینی(ره)

چکیده

جایگاه غلت­ها در نظام­های واجی مشخصه­بنیاد چندان روشن نیست. برخی، غلت­ها را در طبقه­ی واجی واکه­ها قرار می­دهند؛ برخی نیز معتقدند که غلت­ها شاخصه­های صوتی منحصربه­فردی دارند که آن­ها را از واکه­ها و همخوان­ها (اعم از همخوان­های گرفته و رسا) متمایز می­کند. پژوهش حاضر به بررسی ویژگی صوت­شناختی همخوان غلت سختکامی /j/ در نظام آوایی زبان فارسی می­پردازد. برای این منظور، تعدادی کلمه حاوی غلت /j/ را به­عنوان کلمات هدف آزمایش انتخاب کردیم. برای بررسی اثر بافت واکه­ای و جایگاه نوایی بر ویژگی­های صوتی غلت سخت­کامی /j/، این همخوان­ را در سه جایگاه آغازی، میانی و پایانی کلمات در مجاورت تمامی شش واکه­ی زبان فارسی قرار دادیم. برای تحلیل آوایی داده­ها، تعدادی پارامتر صوتی حوزه­ی فرکانس (F1، F2 و F3 و پهنای نوار این سازه­ها) و دامنه­ی انرژی موج صوتی (دامنه­ی انرژی کل، دامنه­ی انرژی فرکانس­های 1-0 کیلوهرتز و 5-1 کیلوهرتز) بر روی ناحیه­ی ایستای غلت سخت­کامی/j/ و واکه­های مجاور اندازه­گیری شد. نتایج پژوهش نشان داد آنچه به شکل پایدار و منظم طیف فرکانسی غلت /j/ را از واکه­ی مجاورش متمایز می­کند، تغییر فرکانس سازه­ها و کاهش دامنه­ی انرژی فرکانس­های میانی و بالا است. این نتایج همچنین نشان داد که میزان باریک­شدگی حفره­ی دهان از /i/ به /j/ آنقدر زیاد نیست که بر مقادیر فرکانس، پهنای نوار و شدت انرژی F1 تأثیر بگذارد و فقط در حدی است که باعث می­شود الگوی واک­سازی حنجره تغییر و دامنه­ی انرژی فرکانس­های میانی و بالا تضعیف شود.

کلیدواژه‌ها


عنوان مقاله [English]

The palatal glide /j/ in Persian phonology

نویسندگان [English]

  • Vahid Sadegh 1
  • zahra sabzali 2
1 Corresponding author, Associate professor, Faculty of Humanities, Imam Khomeini International University, Qazvin, Iran.
2 M. A. in Linguistics, Faculty of Humanities, Imam Khomeini International University, Qazvin, Iran.
چکیده [English]

Glides have a vague status in feature-based models of phonology. Some classify glides with vowels, and others believe glides have characteristics that differentiate them from vowels and consonants. The present research aims at investigating the acoustic properties of the Persian palatal glide /j/. To this end, a number of words were randomly selected to include /j/ in three different phonological positions, namely word-initial, word-medial and word-final. Acoustic analyses were conducted to identify the spectral properties of the glide. The analyses included measuring F1, F2 and F3 as well as their bandwidths, overall intensity and the intensity between 0to 1000 Hz and 1000 to 5000 Hz. The results suggested that both the formant frequencies and the intensity of the mid and higher formant frequencies are significantly different between the glide /j/ and the neighboring vowels. The results were interpreted to indicate that phonation type is the most important articulatory feature that differentiates between /j/ and the surrounding vowels.

Extended Abstract
The idea that glides occupy a phonological category of their own, especially as distinct from the related high vowels /i/ and /u/, has not been accepted by all researchers.  Some prefer the term “semivowel” to that of “glide”, labeling them as vowel-like segments that only function like consonants (Ladefoged & Maddieson, 1996). Others deny any difference between glides and vowels, other than their relative positions in the syllable. For example, Selkirk (1984) has argued that there is no need for a feature distinction between the glides /j, w/ and the high vowels /i, u/, since they can be differentiated instead by syllable theory alone.
Stevens (1998) defines glides as “a class of consonants produced with a constriction that is not sufficiently narrow to cause a significant average pressure drop across the constriction during normal voicing”. The lack of a vocal tract closure producing a significant pressure drop is a clear distinction between glides and other consonants; its acoustic correlate is a lack of abrupt discontinuity in the acoustic signal (Stevens, 2002).  The dividing line between glides and vowels (especially the closely related high vowels), however, has heretofore been less clearly defined.  Chomsky & Halle (1968) suggest that the [-vocalic] feature that differentiates glides from vowels is defined by a constriction that is greater in degree than that for a high vowel; but the threshold boundary required to create this category distinction along the continuum of constriction degrees has not been established in terms of articulation and acoustics. Previous acoustic analyses have found several potential acoustic correlates of the [-vocalic] feature that differentiates glides from related vowels: (1) Glides, inhabiting the syllable boundaries, should have a weaker intensity than the vowels at the syllable nuclei (Stevens, 1998); RMS amplitude (ARMS) provides a quantitative measure of this intensity relationship (Hon Hunt, 2009); (2) The narrow constriction in the front part of the vocal tract for a glide has the effect of decreasing the frequency of the first formant peak (F1) relative to that of a vowel (Hon Hunt, 2009); (3) The bandwidth of the first formant (B1) is expected to be larger for glides than for vowels, again because of the narrower constriction in the vocal tract for the glide segments (Stevens, 1998); (4)  a less sonorous sound segment (such as a glide) might exhibit more of a noise component in its acoustic signal than a more sonorous sound segment (such as a vowel) (Padgett, 2008); (5) he aerodynamic effects of the oral constriction on the glottal source may also have the effect of decreasing the fundamental frequency of phonation (F0) in a glide relative to that in an adjacent vowel. Acoustic modeling suggests that this effect will be most pronounced when F0 and F1 are close together.  Because F0 is strongly affected by prosodic considerations, this source effect may be variably present in different prosodic environments. (Stevens, 1998).
The present research aims at investigating the acoustic properties of the Persian palatal glide /j/. To this end, a number of words were randomly selected to include /j/ in three different phonological positions, namely word-initial, word-medial and word-final, so we could control for the effect of vocalic as well as prosodic context on the acoustic properties of the glide. The words were selected in such a manner to include the six vowels of the Persian language. The data were elicited by 9 native speakers of Persian, aged 20 to 30 years old. Recordings were made in a sound-attenuating chamber in the laboratory of linguistics at IKIU, with subjects seated with a fixed microphone approximately six inches from the lips. The subjects were prompted by text appearing on a computer monitor to read the phrases that were displayed on the screen.
All acoustic analyses were carried out in Praat. The Acoustic analyses included measuring F1, F2 and F3 as well as their bandwidths, overall intensity and the intensity between 0 to 1000 Hz and 1000 to 5000 Hz. The measurements were made on the steady state of /j/ and the preceding vowel.
The results suggested that both the formant frequencies and the intensity of the mid and higher formant frequencies are significantly different between the glide /j/ and the neighboring vowels. Indeed, the formant frequencies and the intensity of the mid and higher formant frequencies were the only two acoustic properties that systematically distinguished the glide /j/ from the neighboring vowels. The results further suggested that the magnitude of the narrowing of the oral cavity in transition from/i/ to /j/ was too small to excite changes in the first format frequency and bandwidth, but it sufficed to produce changes in phonation type, and thus intensity in the mid and higher formant frequencies. The results were interpreted to indicate that phonation type is the most important articulatory feature that differentiates between /j/ and the surrounding vowels.

کلیدواژه‌ها [English]

  • intensity of mid and higher formant frequencies
  • palatal glide
  • feature-based models of phonology
  • high front vowel
  • acoustic correlates
بیجنخان، محمود. (1392). نظام آوایی زبان فارسی.  تهران: انتشارات سمت.
ثمره، یدالله. (1378). آواشناسی زبان فارسی، آواها و ساخت آوایی هجا. ویراست 2. تهران: مرکز نشر دانشگاهی.
حقشناس، علی محمد. (1356). آواشناسی. تهران: انتشارات آگاه.
یارمحمدی، لطف­الله. (1364). درآمدی به آواشناسی. تهران: مرکز نشر دانشگاهی.
Refrences:
Bijankhan, M. (2013). Phonetic System of the Persian Language. Tehran: Samt.                                                                                                                    
Catford, J. (1988). A Practical Introduction to Phonetique de Strasbourg.
Catford J. C. (2001). A Practical Introduction to Phonetics. Oxford: Clarendon Press.
Chitoran, I. (2002). A perception-production study of Romanian diphthongs and glide-vow sequences. Journal of the International Phonetic Association, 32 (2), 203-222.
Chomskey, N., & Halle, M. (1968). The Sound Pattern of English. Cambri Massachusetts: MIT Press.
Haghshenas, A.M. (1977). Phonetics. Tehran: Aghah.
Hon Hunt, E. (2009). Acoustic Characterization of the Glides /j/ and /w/ in American English. PhD dissertation. Cambridge, MA: Massachusetts Institute of  Technology.
Jakobson, R., Fant, C. G., & Halle, M. (1968). Preliminaries to Speech Analysis: The Distinctive Features and their Correlates, Technical Report No. 13, Massachusetts Institute of Technology, Acoustics Laboratory, Cambridge, and  Massachusets.
Kenstowicz, M., & Kisseberth, C. (1979). Generative Phonology. San Diego Academic Press.
Keyser, S. J. & Stevens, K. N. (1994). Feature Geometry and the Vocal Tract. Phonology II, 2, 207-236.
Ladefoged, P. (2005). An Introduction to Phonetic Data Analysis. Blackwell  Publishing.
Maddieson, l. (2008). Glides and germination. Lingua 118, 1926-1936.
Nevins, A., & Chitoran, l. (2008). Phonological representations and the variable patterning of glides, Lingua, 118, 1979- 1997.
Padgett, J. (2008). Glides, vowels, and features. Lingua, 118, 1937-1955.
Parker, S, G. (2002). Quantifying the Sonority Hierarchy, PhD Thesis, University  of Massachusetts, Amherst.
Sadeghi, V. & Mansoory Harehdasht, N. (2016). Persian Sentence Stress Production by Mandarin Chinese Speakers. Journal of Teaching Persian to Speakers of Other Languages,25) 1(, 95-119.
Samare, Y. (1999). Persian Phonetics, Sound and Syllable Structure. 2nd ed. Tehran: Center of academic publications.
Selkirk, E. o. (1984). On the major Class Features and Syllable Theory. In M. Aronoff, & R. T. Oehrle (Eds.), Language Sound Structure (pp. 107-136). Cambridge, Massachusetts: MIT Press.
Sluijter, A. & van Heuven, V. (1996a). Spectral balance as an acoustic correlate  of linguistic stress, J. Acoust. Soc.Am., 100)  4(, 2471-2485.
Sluijter, A. & van Heuven, V. (1996b). Acoustic correlates of linguistic stress and  accent in Dutch and American English,  Proceedings of ICSLP 96, pp. 630-633. Philadelphia, PA: Applied Science and Engineering Labrotaries, Alfred I. DuPont Institute.
Stevens, K, N. (1998). Acoustic Phonetics. Cambridge, Massachusetts: MIT Press.
Stevens, K. N. (2000). From Acoustic Cues to Segments, Features and Words.Fifth 
 ICSLP, Vol1, 1-8.
Stevens, K, N. & Hanson, H. M. (2009). Articulatory-acoustic relations as the basis of distinctive contrasts. In W. Hardcastle, & J. Laver (Eds.), Handbook of Phonetic Sciences (2nd Ed.). Malden, Massachusetts: Wiley- Blackwell.
Yarmohammadi, L. (1985). An Introduction to Phonetics. Tehran: Center of  academic publications.