Oral cavity role in speech breathing and speech creation.

Human respiratory system besides its main function – lung gas exchange providing – participates directly in speech sounds creation. Acoustic effects main creative ways are air stream stoppage by rhythmic voice cords. Tonal and noisy sounds occur while air passage with too large velocity through narrowings formed in this or that place alongside respiratory tracts. Thus, speech appears due to respiratory system actions, providing necessary pressure and air flows in speech-forming tract as well as due to this tract elements movement managing air streams. Oral cavity organs for example lips, tongue and teeth participate in acoustic effect creation because expiration in course of communication occurs through mouth.

Respiratory apparatus activity in course of speech is called speech respiration. Normal speech with correct and distinct sounds prononciation is tightly connected with dental rows integrity. Teeth loss especially anterior lead to lisping, prononciated sounds clearence decreasing and even to losing of possibility to prononciation of separate from them. There may be salivation and saliva releasing through the gaps forming despite absent teeth. Speech defects can be also determined by disorders of salivary glands functions (dryness in mouth), masticatory musculature (muscules contracture and motor nerves paralysis), temporal-mandibular joint (mandibule contracture) as well as congenital or aquired dfects of facial-maxillar region organs, organs anomalies and uncorrect denturing.

One of main reasons of speech function disorder are dental rows defects especially of dental-maxillar system frontal region. Sound generation distortion, energy consumptions change under speech activity are observed. That’s why dentist in course of denturing must choose denture construction at which speech activity becomes optimal as for clarity of generated sounds and minimal energy on its loss.

Human being has no specific speech organs. He uses respiration, mastication and swallowing organs for speech-forming. But he has specialized vocal apparatus (larynx and vocal cords) for speech vocal constituent. Organs participating in speech-forming, are divided into 2 groups: respiration organs (lungs with bronchi and trachea) and organs directly participating in voice-forming. One can differentiate active (moved) having the ability to change their volume and shape of speech tract and create obstacles fro expirated air in them; and passive (motionless) without such ability.

Active speech-forming organs:

· larynx;

· pharynx;

· soft palate;

· tongue;

· lips.

Passive organs:

· teeth;

· hard palate;

· nasal cavity;

· additional sinuses.

All these structures from the point of view of speech-forming perypheral mechanism one can imagine as 3 interconnected parts:

· generatory;

· resonatory;

· energetic.

There are 2 resonators:

· tonal – larynx;

· noisy – due to fissures creature in oral cavity.

Other resonators classification:

· 2 modulating – mouth and pharynx;

· 1 non-modulating – nasopharynx with additional sinuses.

2 energy sources:

· sceletal intercostal muscles, diaphragmal, abdominal;

· tracheobronchial tree smooth muscles.

Vascular reactions in sound-forming have vessel reactions in respiratory ways and vocal tract mucosa. Resonator function in sound-forming process depends on these parts blood filling state.

Respiratory ways and vocal tract mucosa glands secretion also influences on speech-producing. Its increasing influence on vocal tract resonatory features. Excessive secretion in naso-pharynx inhibits nasal sounds reproduction causing nasolaly. Hypersalivation influences on all sounds in which oral cavity, teeth, tongue and lips participate. This is the sphere of speech-forming odontogenic aspect. Every dentist should pay the attention to this aspect. Vocal tract is important executive part of speech-forming system. Here phonemic and whispered constituents of speech are formed. This part activity mostly is under competention of dentist. Dental rows integrity injury (especially incisives) leads to dental sounds forming changing and inhibiting (whistle, lisping). Pathological structures on tongue back leads to sounds reproducing inhibiting and disorders in labial (of lips) region. Changed occlusion influences greatly onto phonation result. It is especially expressed at opened, crossed occlusions, prognathy and progeny.

Phonation disorders at different changings in oral cavity receive corresponding names. Disorder delt with cleft palate (hard palate fissure) is called palatolaly. At anomalies in tongue structure and function occuring articulational disorders receive the name glossolaly. Uncorrect teeth structure and their localization in alveolar archs especially of anterior group (incisives and canines) are often reason of dyslalies. All mentioned dentist must take into account while treaty influencing in oral cavity performance.

Surgeon-dentist must forecast the possibility of speech-forming function in course of operations in oral cavity organs. Articulation mechanism knowledge is of essential importance for orthopedic dentist. Removable dentures production, especially at wide adenthias or complete teeth absence leads to articulational correlations changing in oral cavity. Naturally, it influences on vocal apparatus resonator function. Occlusion overstating at denturing, artificial teeth uncorrect installation and even well-done denture always at first stages of adaptation lead to speech-forming retardation. Patients with removable dentures often complaint on this or that dyslalies signs: sound-production inhibiting, additional whispering, whistle and lisping. All this is necessary to take into account at dentures constructing and creation, especially for people which use speech actively in their working activity (artists, singers, lecturers, dictors, teachers). Famous statement “to train somebody’s voice” to singer, artist, dictor or teacher means to tune respiration and articulation by definite behavioural measures usage.

In course of food mastication and food piece swallowing respiration changings take place which belong to protective respiratory reflexes. They are expressed in breathing stoppage: in course of swallowing jaws are closed, soft palate is rised, contracting palato-pharyngeal muscles form septum between mouth and nasal cavity. Entrance into larynx is closed by epiglottis and vocal cords close vocal fissure. That’s why food piece when pharyngeal muscles contraction can go only in oesophageal foramen.

Thus, at the end of our lecture we must to remember you that healthy breathing – is nasal, as slow and seldom as possible, with its lack in course of inspiration and, especially, after it. While prolonging the inspiration, we stimulate vegetative nervous system sympathetic part work with all following consequences. While prolonging the expiration, we carry carbonic acid in blood more and longer that positively influences on blood vessels tone (decreases it) will all following consequences. Due to this oxygen under such situation can come in the farthest microcirculative vessels preventing disorders of their function and development of many diseases. Correct breathing – is a prevention and treatment of big group of diseases not only of respiratory system but also of other organs and tissues! Breath for enjoy!

 

Lecture 7