Chapter One Flashcards
Domains of speech science
Levels
Perceptual
Acoustic
Aeromechanical
Structural
Muscular
Neural
Domains of speech science
Subsystems
Pharyngeal
VeloPharyngeal/ nasal
Laryngeal
Breathing
Domains of speech science
Application
Forensics
Manegment
Evaluation
Mechanism
Neural Level of Observation
●Encompass nervous system events during speech production
○Brain, spinal cord, cranial and spinal nerves important to speech production
○Some voluntary and some automatic
○Some involve awareness and others do not
●Include all events that qualify as motor planning and execution
●All forms of afferent and sensory information that influence ongoing control of speech production
Muscular Level of Observation
Concerned with the influence of muscle forces on speech production
●Muscles are effectors that respond to control signals from the nervous system
●Inferences about muscle activities are made from measurements of the forces or movements generated by different parts of the speech production apparatus
●Forces and movements are usually accomplished by groups of muscles working together
Structural Level of Observation
●Deals with anatomical structures and movements of the speech production apparatus
●Concerned with the many muscular and non-muscular structures that make up the speech apparatus, including bone, muscle, ligaments, and membranes
●Also concerned with displacements, velocities, accelerations/decelerations of structures and how they are timed in relation to the movements of other structures
○Certain structural observations can be made with the naked eye, whereas others are hidden from view or are too rapid to be followed with the naked eye and require use of instrumental monitoring
●“Speech reading” (lip reading) has roots at this level
Aeromechanical Level of Observation
Considers the role of air in the process of speech production
●Movements of structures impart energy into the air by compressing and decompressing it and causing it to flow from one region to another
●The airstream generated is modified by structures of the speech production apparatus that lie along the passageways
●Products of the aeromechanical level are complex, rapid, and nearly continuous changes in air pressures, airflows, and air volumes
Acoustic Level of Observation
Pertains to the generation of speech sounds
○Sonorous, buzzlike, hisslike, and poplike sounds that result from speaker’s valving of the airstream in different ways and at different locations within the speech production apparatus
●The raw sound is filtered and conditioned by its passage through the apparatus and radiates from the mouth or nose, or both, in the form of very fast and nearly continuous air pressure changes experienced as sound waves
●Sound waves propagate from the speaker’s mouth and can be coded in terms of frequency, sound pressure level, and time
●This constitutes speech and acoustic representation of spoken language
●Acoustic level is important in face-to-face communication and use of telephones, radios, televisions, hearing aids, cochlear implants, and various forms of recording
Perceptual Level of Observation
Auditory analysis of the speech signal allows the listener to recognized phonetic cues that are consistent with the listener’s knowledge of the sound system of a language
●The speaker perceives and monitors their own speech acoustic signal to check that the signal that was intended was indeed produced
●Visual information also contributes to the perception of speech
●Listeners naturally combine acoustic and visual information for the most effective perception of speech
Subsystems of Speech Producti
Breathing apparatus
●Laryngeal apparatus
●Velopharyngeal-nasal apparatus
●Pharyngeal-oral apparatus
Breathing Apparatus
Breathing Apparatus
●Includes structures below the larynx within the neck and torso
○Pulmonary apparatus (pulmonary airways and lungs)
○Chest wall apparatus (rib cage wall, diaphragm, abdominal wall, and abdominal content)
●During speech production, the breathing apparatus provides the necessary driving forces
○Simultaneously serves functions of ventilation and gas exchange
●Role of breathing apparatus is fundamentally important to speech production
Laryngeal Apparatus
Laryngeal Apparatus
●Larynx lies between the trachea (windpipe) and pharynx (throat)
○Adjusts coupling between the two
●At times, the laryngeal airway is open to allow air to move in and out of the breathing apparatus
●Other times it is adjusted to obstruct or constrict the airway
●Rapid vibrations of vocal folds within the larynx create voiced sounds
●Larynx can also produce noisy sounds, like a whisper
Velopharyngeal-Nasal Apparatus
Velopharyngeal-Nasal Apparatus
●Consists of the upper pharynx, velum, nasal cavities and outer nose
●Significantly influences the aeromechanical and acoustic levels of the speech production process
●When breathing through the nose, the velopharyngeal-nasal airway is open
●When speaking, the size of the velopharyngeal port varies, depending on the nature of the speech produced
○Consonant sounds with high oral pressure are associated with airtight closure of the velopharyngeal port
○Nasal consonants are produced with an open velopharyngeal port
Pharyngeal-Oral Apparatus
Pharyngeal-Oral Apparatus
●Comprises the middle and lower pharynx, oral cavity, and oral vestibule
●During running speech production, the apparatus is typically open during inspiration
●The apparatus makes different adjustments for consonant and vowel productions during expiration, including generation of transient, voiceless, and voiced sounds and filtering of those sounds
Domains of hearing science
Levels
Neural
Mechanosensory
Muscular
Structural
Aeromechanical
Acoustic
Domains of hearing science
Subsystem
Central auditory pathways
Inner ear and auditory nerve
Middle ear
Outer ear
Domains of hearing science
Application
Forensics
Manegment
Evaluation
Mechanism
Acoustic Level of Observation
Acoustic Level of Observation
●Refers to frequencies, amplitudes, and temporal characteristics of pressure waves that enter the ear at its opening to the atmosphere
●The signal can be analyzed to extract and modify spectral content and the way in which it varies over time
●Relevant to establishing the analysis capabilities of the human auditory system
Aeromechanical Level of Observation
●The auditory system responds to the acoustic pressure wave with mechanical vibrations of auditory structures (i.e., tympanic membrane and ossicles)
●The mechanical vibrations replicate the vibrations in the air that create pressure waves, but only to a point
●Differences between auditory analysis of frequency, amplitude, and temporal characteristics compared with characteristics in pressure waves reveal the analysis capabilities of the human ear
Structural Level of Observation
●Includes anatomy of the auditory system and the physiology of hearing
●The anatomy is designed for transmitting vibratory energy from the outer ear to the inner ear
●Many structures are moving components–tympanic membrane, ossicles, fluid and membranes within the cochlea
●Peripheral nerve is dedicated to transmission of auditory information from the cochlea to the central nervous system
●Within the central nervous system complex pathways carry auditory information from the brainstem to the cortex
Muscular Level of Observation
Muscular Level of Observation
●Contraction of two muscles in the middle ear stiffens the ossicles and tympanic membrane, and in doing so, reduces the transmission of sound energy from the air to the cochlea
○Stapedius muscle plays a primary role in the acoustic reflex that occurs when the auditory system is exposed to extremely intense sounds
●A few muscles cause subtle movements of the pinna, but the ability to move the structure has mostly disappeared in humans
Mechanosensory Level of Observation
Mechanosensory Level of Observation
●Refers to the transduction of mechanical energy to neurochemical energy that is observed when fluid displacements within the cochlea (mechanical portion) are transformed into neurochemical energy (sensory portion)
●This transformation takes place at the hair cells within the cochlea
○Fluid movements bend the hair cells causes the electrical potential of hair cells to change releases a neurotransmitter that initiates firing of nerve fibers in the auditory nerve
●Hair cells are the sensory receptors of audition
Neural Level of Observation
Neural Level of Observation
●Auditory nerve
○Peripheral nerve that emerges from the cochlea and inserts into the brainstem
●Inside the brainstem the fibers travel to brainstem nuclei, which send fibers to increasingly higher levels of the central nervous system until they reach cell bodies in the cortex
●These fibers (i.e., tracts) constitute the central auditory pathways
●Fibers within the auditory nerve and nuclei and tracts that compose the auditory pathways have a tonotopic arrangement, meaning specific fibers and cells respond selectively depending on the frequencies of the incoming stimulus
Subsystems of the Auditory System
Subsystems of the Auditory System
●Conductive Component
○Outer Ear
○Middle Ear
●Sensorineural Component
○Inner Ear and Auditory Nerve (CN VIII)
●Central Auditory Pathways
Outer Ear
Outer Ear
●Pinna
○When exposed to sound pressure waves, the pinna emphasizes energy at certain frequencies and de-emphasizes energy at other frequencies
○May play a role in localization of sound sources
●External auditory meatus
Middle Ear
Middle Ear
●Air-filled cavity
●One surface layer of the three-layer tympanic membrane
●3 connected ossicles that transmit sound energy to the cochlea
●Eustachian tube the equalizes pressure and opens to the pharynx
●Stapedius and tensor tympani muscles that stiffen ossicles
●Segments of several nerves and blood vessels
Inner Ear & Auditory Nerve
Inner Ear & Auditory Nerve
●Bony, fluid-filled cochlea
○Inside the snail-shaped cochlea is a membrane containing the sensory organs of hearing
■The membrane and its complex structures are displaced by movement of the fluid caused by vibration of the ossicles
●Ganglia
●Cranial Nerve VIII
○Composed of the auditory and vestibular nerves
Central Auditory Pathways
Central Auditory Pathways
●Include a series of nuclei and fiber tracts that connect the nuclei to other parts of the brain
●Pathways are dedicated to transmission of auditory info from the brainstem to the auditory cortex
●Complex analysis of auditory information takes place in the cortex, including analysis resulting in speech perception
