DE LA ADMINISTRACIÓN DE LOS RECURSOS FINANCIEROS

From ordinary X-ray sagittal projections, it is difficult to determine the extent of velopharyngeal (palatopharyngeal) closure in non-nasal sounds. Tomography provides pictures of sharper contrast and records a more accurate cross section. On the basis of tomographic

64

studies, Bjork (1961, supplement 202, pp. 1-94) concludes that velo­ pharyngeal closure may be less complete than X-ray photographs show. His study indicates marked narrowing of the nasopharyngeal opening, both from lateral and from anterior-posterior aspects. Fant (1964, p. 231) suggests that the elevated velum as viewed tomographi- cally may not occlude the velopharyngeal opening to the extent phoneticians often assume. Zwitman et al. (1973, p. 473) find that "[T]he degree of lateral pharyngeal wall movement varies among normal individuals. . . . Conflicting descriptions of lateral wall move­ ment probably are attributable to differences among individuals.”

Zwitman et al. (1974, pp. 368-370) established that several fac­ tors contribute to pharyngeal closure:

1. Lateral walls move medially and fuse, resulting in a purse-string closure as the velum touches the approximated section of the lateral walls.

2. Lateral walls almost approximate, with the velum contacting the lateral walls and partly occluding the space between them. A small medial opening is observed in some cases.

3. Lateral walls move medially, filling the lateral gutters and fusing with the raised velum as it contacts the posterior wall. 4. Lateral walls move slightly or not at all. Velum touches

posterior wall at midline, and lateral openings are observed during phonation.

Nearly half of the 34 normal subjects examined in this study showed incomplete velar closure on non-nasals. Fritzell (1979, pp. 93-102) also suggests that muscular action in velopharyngeal closure varies among normal subjects. Such studies are of impor­ tance in providing probable factual support for theories of "the open nasal port” in some form in singing.

The possibility of at least some coupling of the nasal resonator to the buccopharyngeal resonator has also been recognized by Sund- berg (1977a, p. 90) in dealing with the acoustics of the singing voice: "It is just possible . . . that the nasal cavity has a role in singing of vowels that are not normally nasalized.” It should be kept in mind that there may well be considerable individual physiological varia­ tion with regard to nasopharyngeal coupling.

Implications for the technique of singing are significant. Limited degrees of nasopharyngeal coupling (some aperture of the port) seem to be induced by the numerous vocalises that make use of nasal con­ sonants as "placement” devices. The perception of nasality in non­ nasals is always, of course, to be avoided. However, vocal sound per­

The Resonant Voice 65 ceived by the listener as resonant but non-nasal may in fact result from some degree of nasopharyngeal coupling (House and Stevens, 1956, p. 218). The ratio in balance between oral and nasal resonance may depend on how the posterior apertures into the nasal cavities relate to the size of the oral cavity. Nimii et al. (1982, p. 250) com­ ment that

Cartilage of auditory tube Tensor veli palatini

Levator veli palatini Ascending palatine artery Pterygo­ mandibular raphe Salpingo- pharyngeus Palatoglossus Styloglossus Superior con­ strictor Palatopharyngeus Stylohyoid lig. Glossopharyn­ geal n. Inferior con­ strictor Middle con­ strictor Mucous membrane of pharynx, cut Epiglottis

Figure 4.7. Median sagittal section of the head showing a dissection of the interior of the pharynx after the removal of the mucous membrane. (In order that the structures may be displayed satisfactorily, the bodies of the cervical vertebrae have been removed and the cut posterior wall of the pharynx then drawn backward and laterally. The palatopharyngeus is drawn backward to show the upper fibers of the inferior constrictor, and the dorsum of the tongue is drawn forward to display a part of the styloglossus in the angular interval between the mandibular and the lingual fibers of origin of the superior constrictor. (From Gray’s Anatomy, 36th ed., ed. by Peter L. Williams and Roger Warwick, 1980. Edinburgh: Churchill Living­ stone. By permission.)

6 6 The Structure of Singing

[I]t is apparently quite usual for velar elevation to vary dur­ ing connected speech, with changes in velar position, and thus in velopharyngeal port size, produced to enhance or prevent nasal coupling, as needed, for the segments in the phonetic string . . . [Vjelar elevation varies directly with the oral cavity constriction of oral segments.

This group of researchers concludes that one must expect “some individual differences, even among normal speakers" as to the mechanical means for velopharyngeal closure (1982, p. 255).

G e n io g lo s s u s B u c c i n a t o r ( c u t ) S u p e r i o r c o n s t r ic t o r S t y lo g l o s s u s T h y r o h y o i d m e m b r a n e C r i c o t h y r o i d T e n s o r v e l i p a l a t i n i veli p a la tin i T r a n s v e r s e p r o c e s s o f a t la s I n f e r i o r o b l iq u e P teryg oid h a m u l u s Rectus capitis lateralis S u p e r i o r o b l iq u e A n t e r i o r i n t e r - t r a n s v e r s e process o f axis S t y l o p h a r y u n q t u s c o n ­ s t r i c t o r I n f e r i o r c o n ­ s t r i c t o r

Figure 4.8. A dissection showing the muscles of the tongue and pharynx. (From Gray’s Anatomy, 36th ed„ ed. by Peter L. Williams and Roger War­ wick, 1980. Edinburgh: Churchill Livingstone. By permission.)

The Resonant Voice

67

Maxillary Lateral pterygoid artery plate, partly excised Tensor veli palatini

Lateral thyrohyoid ligament. Inferior constrictor. Tuberosity of maxilla Middle menin­ geal artery Spine of sphenoid Levator veli palatini Buccinator Pterygoid hamulus Parotid duct Pterygo­ mandibular Glossopharyngeal n. Styloglossus {cut) raphe Byoglossus Middle constrictor Mylohyoid (cut) Stylohyoid ligament Geniohyoid Greater cornu of hyoid bone

Lesser cornu of hyoid bone Thyrohyoid membrane Interna Uaryngeal nerve Superior laryngeal vessels

Recurrent laryngeal nerve_

Cricothyroid ligament Cricothyroid Oesophagus-

Figure 4.9. The buccinator and the muscles of the pharynx. (From Gray's Anatomy, 36th ed., ed. by Peter L. Williams and Roger Warwick, 1980. Edin­ burgh: Churchill Livingstone. By permission.)

6 8 The Structure of Singing

The answers are not all in, regarding the mode by which velo­ pharyngeal closure may be modified. According to Nimii et al. (1982, p. 253):

There is general agreement that the velum is elevated and retracted primarily by the levator palatini muscle. . .. The point of controversy revolves around the putative role of other muscles in the velopharyngeal port region in bringing about movement of the lateral pharyngeal walls at various levels relative to the point of velopharyngeal closure.

This piece of research concludes:

We believe that the levator palatini is the muscle primarily responsible for the medial movement of the lateral pharyn­ geal wall from the level of velopharyngeal closure (which varies with the type of phonetic segment produced) to the superior limit of that movement. That the interpretation that the levator palatini is responsible for both the lateral wall and velar movements is a valid one is supported by the d a ta .. . .

How one conceives of "opening the throat” and "placing the voice” leads directly to specific kinds of muscle activity in the velo­ pharyngeal area. The levator veli palatini (levator palatini), the tensor veli palatini, the palatoglossus and palatopharyngeus, and the muscu- lus uvulae (see Appendix III and Figures 4.7, 4.8, and 4.9) respond to such concepts. The presence or lack of "resonance” in the singing voice is closely tied to adjustments made in the velopharyngeal region. The extent to which the nasal cavities are united with the rest of the resonator tube partly determines the perception of "reso­ nance.” As with the exact character of velopharyngeal closure itself, not all the answers are clear regarding the degree to which velo­ pharyngeal closure may be modified in singing. Additional attention to balanced resonator adjustment through the use of consonants (including the nasals) will comprise the material of other chapters. However, the resonant, well-balanced vowel in singing must first be considered.

CHAPTER 5

The Well-balanced Vowel