Speech Production Process 4 Processes in Speech Production

Speech Production Process

4 Processes in Speech Production Respiration w Phonation w Resonance w Articulation w

Respiration: Power Mechanism w Provides the energy for sound w Breathing is an aerodynamic process • a difference in air pressure is created between the thoracic cavity and the atmospheric pressure outside the body

2 Phases of Breathing w Inhalation - muscles of the thoracic cavity expand the chest; air pressure decreases and air is taken in • air pressure is less in thorax than in atmosphere and air flows in w Exhalation - when the pressure is greater in thorax, air flows out • there is a decrease in chest cavity and an increase in air pressure

Breathing for Speech vs Breathing for Life w Breathing for speech uses same muscles, but is controlled more • exhalation phase is longer than inhalation phase for speech w Breathing for life, inhalation and exhalation phases are same

Phonation: Vibrating Mechanism Phonation is the rapid opening and closing of the vocal folds for sound w the vocal folds lie horizontally in the larynx w they attach anteriorly to the thyroid cartilage and posteriorly to the artynoid cartilages; they are free in the middle w the opening in the middle of the vocal folds is the GLOTTIS w

Phonation (con’t) adduction of the arytnoids closes the vocal folds w the middle of the vocal folds vibrate to and from midline w vibration of the vocal folds produces voicing w Position of vocal folds • open (abducted) • closed (adducted) w

3 major aspects of voice influenced by vocal fold movement w Pitch - frequency of vibration • the rate of vocal fold vibration is called the FUNDAMENTAL FREQUENCY • this is measured in terms of Hz or cps • therefore, if the vocal folds vibrate 200 cps it is a fundamental frequency of 200 Hz • an increase in pitch involves an increase in frequency (hi pitch; hi frequency) • the frequency of vocal fold vibration depends on the mass and length of the vocal folds and the tension

3 major aspects (con’t) Loudness - intensity of sound • involves the amount of energy generated by the vocal fold movements • intensity increases with increased air pressure from the lungs and increased amplitude of the vocal fold vibration w Quality - the sound quality of the voice w • this is affected by the pattern of movement of the vocal folds

Resonance: The characteristic quality of the voice The speech mechanism is a resonator -- it is like an air-filled tube (closed on one end and open at the other end) w the fundamental frequency generated at the vocal folds is resonated in the vocal tract that is now also vibrating -- the vibration of the vocal tract is the HARMONIC FREQUENCY w every body or object has its own natural frequency w those frequencies that match the vocal tract’s natural frequency will be amplified this is resonance w

Resonance (con’t) Pharynx is the primary resonator w recall the 3 parts of the pharynx (nasopharynx, oropharynx, laryngopharynx) w the nasopharynx and oropharynx are the 2 resonating systems w these 2 systems provide resonance to sounds that pass through the oral and nasal cavities w

Articulation w Serves to produce the different configurations which make up the different speech sounds

Dynamics of Speech Production w Speech is a dynamic rather than a static phenomenon • the articulators are in a state of constant movement during speech w Individual speech sounds are described in terms of target positions; ongoing speech is better thought of in terms of movement

Dynamics of Speech Production (con’t) w Sounds in a word don’t follow each other like printed letters w spoken sounds overlap with each other • this is referred to as COARTICULATION

Co-articulation as the articulators are in the process of forming one sound, their positioning prepares them for the sound that follows w speech sounds influence and are influenced by other sounds within a phonetic environment w the dynamic nature of speech means that we are planning events before they occur w we may articulate one segment before completing another • we may be as much as several segments ahead or behind in our motor activity w

Co-articulation Important clinically because a client cannot simply be taught to pronounce a given sound in one simple way • need to provide practice in a variety of phonetic environments w Examples of co-articulation • /iki/ - point of artic for /k/ is more forward (palatal) than velar • / uku/ - point of artic for /k/ is more posterior (uvular) than velar • /aka/ - point of artic for /k/ is actually velar • sneeze ~ snooze; see ~ Sue w

Co-articulation (con’t) w Why do we have co-articulation? • It’s not because we’re lazy. • There are too many demands on the speech mechanism than there is time to fulfill them • normal conversation is produced at a rate of between 10 -20 segments/second which implies a maximum of 100 msec/segment • however, it takes much longer than this to complete any speech gesture and then return to the starting point • THEREFORE, something has to give -- thus, compromise gestures are made

Co-articulation (con’t) w It is true that dialects and registers of speech (formal vs informal) differ in the amount of coarticulation that can be made • non-native speakers want to learn this allowable accommodations in order to sound more normal • the second language learner often has a hypercorrect pronunciation that sounds strange because it lacks the usual shortcuts that native speakers take w Need to distinguish co-articulation from assimilation • co-articulation means that 2 different sounds were being articulated simultaneously • one tongue movement was made for both sounds

Assimilation w w w Refers to changes that cross phonemic boundaries and results in a major phonetic change The resulting change is to a different sound (phoneme) Co-articulation results in non-phonemic differences In assimilation, there is a major change in the place of articulation, manner of articulation, or voicing of a segment, such that it falls into a different phonemic category Examples of assimilation • I miss you; got you; had you; phone booth

Types of Assimilation (direction of accommodation) w Regression assimilation - a particular sound influences the sound immediately preceding it • EX: miss you • also referred to anticipatory, or right-to-left assimilation w Progressive assimilation - a given sound produces changes in the sound that follows • EX: cats dogs • left-to-right assimilation

Other Combinatory Phenomena w Elision (ellipsis) - when a segment or several segments are left out of a word when it is pronounced • dialectal differences in elision, e. g. , “interesting”, “secretary” w Epenthesis - the insertion of a sound, generally to break up consonant clusters or to provide a transition between sounds

Other Combinatory Phenomena (con’t) w Metathesis - when two adjacent segments are reversed • EX: “ask” [æks] • dialectal metathesis