CDI 315
Okay, here's a study guide based on your request and the provided sources:
I. Basic Physics Concepts
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Inertia: The sources do not directly define inertia. However, they imply that when undisturbed, a system is at equilibrium and remains so until acted upon1.
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Momentum: The sources indicate that the greater the mass or speed of an object, the harder it is to stop2. While this does not explicitly define momentum, it describes a key principle related to momentum.
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Work: The provided sources do not define work.
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Speed The sources do not directly define speed. However, they indicate that speed is relevant when considering the motion of an object2.
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Velocity The sources do not directly define velocity.
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Uniform Motion The sources do not directly define uniform motion.
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Acceleration The sources do not directly define acceleration.
II. States of Matter
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There are three states of matter: solid, liquid, and gas3.
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Solids maintain the same shape and volume at a constant temperature4....
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Liquids maintain their volume but conform to the shape of their container5.... The particles of a liquid are attracted to each other, but not as tightly as in a solid5.
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Gases expand to fill their container and do not maintain a specific shape or volume5.... Gas particles are not attracted to each other and are in random, constant motion5.
III. Sound Waves
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What is a wave? The sources define a wave as a disturbance that travels through a medium8.
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Types of Waves:
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Longitudinal waves are a series of pressure disturbances where the displaced particles of the medium move parallel to the wave's motion9. Sound waves are longitudinal10. They are characterized by compressions, where air particles are close together, and rarefactions, where air particles are more separated11.
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Transverse waves are waves where the displaced particles travel perpendicular to the motion of the wave9. These waves have crests and troughs9.
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Periodic waves repeat the vibration pattern many times, while a pulse wave is a single disturbance that does not repeat itself8....
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Properties of Sound Waves:
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Frequency is how often air molecules vibrate or how often the sequence of compressions and rarefactions repeats itself. It is measured in Hertz (Hz), which is the number of cycles per second12.
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Periodicity is the time between neighboring points of compression or rarefaction12. High frequency corresponds to a short period12.
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Intensity is the measure of a sound wave's power12. Speech intensity is measured in decibels of sound pressure level (dB SPL), and a 6 dB increase is equal to a doubling of sound pressure13.
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Wavelength is the distance traveled by one vibration cycle (from rarefaction to rarefaction or compression to compression). There is an inverse relationship between wavelength and frequency; the higher the pitch (frequency), the shorter the wavelength14.
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Complex Tones: Complex tones are periodic, with a repeating underlying pattern15.
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Fundamental Frequency (f0): The f0 of a complex tone is the lowest frequency of the pure tones that comprise the complex tone16. The f0 is the loudest of the tones and how frequently the larger pattern repeats itself16.
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Incident and Reflected Waves:
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When a sound wave encounters a boundary, a portion of the wave's original energy (the incident wave) is transmitted into the new medium17.
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A portion of the wave is also reflected back to the sound's origin (reflected wave)17.
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Resonance: Resonance is the increase in the amplitude of an object's vibration when a force is applied at its natural frequency18. A natural frequency is the frequency at which an object vibrates most easily18. The size of an instrument's resonating cavity affects its natural resonant frequency19.
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When a medium (air or tissue) vibrates at its resonant frequency, a standing wave is formed20. The vocal tract produces standing waves21.
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Harmonics: Harmonics are higher resonant frequencies that are multiples of the f0 in a complex tone22.
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The first harmonic is equal to the f022.
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The second harmonic (first overtone) is twice the frequency of the f022.
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The third harmonic (second overtone) is three times the frequency of the f022.
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Free and Forced Vibration: The sources do not explicitly define free or forced vibration, but do discuss resonators19. The air inside an instrument, along with the material it is made of, affect how the instrument sounds. Our vocal tract is an acoustic resonator19.
IV. Respiration
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The sources do not explicitly discuss Boyle's Law or its relation to breathing, nor do they describe the location of the lungs or the diaphragm.
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The sources do not explicitly describe what the lungs are made of.
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The sources do not explain the specific process of inhalation and exhalation.
V. Vocal Folds
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Vocal folds are located within the larynx, anterior to the esophagus23. They are attached anteriorly to the thyroid cartilage and posteriorly to the arytenoid cartilages23. The vocal folds are the entrance to the trachea, which leads to the lungs24.
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The epiglottis folds over the vocal folds and entrance to the lungs during a swallow24.
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The vocal folds can be abducted (open) or adducted (closed)25.... When the vocal folds are abducted, the rings of the trachea are visible25. When adducted, the tracheal rings are not visible26.
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Vocal folds are very small, about the size of a pinky fingernail25.
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Structure: Vocal folds are made up of three layers27...:
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Epithelial Tissue: The outermost layer, which is very thin27.
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Lamina Propria: This layer has three layers27: a. Superficial layer b. Intermediate layer c. Deep layer
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Vocalis Muscle: Also called the thyroarytenoid muscle27....
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Body/Cover Model: This model groups the layers of the vocal folds28.
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Layer 1: Cover - includes the epithelium and the superficial layer of the lamina propria and is made of mucosa, collagen, and elastin fibers28.
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Layer 2: Transition- includes the intermediate and deep layers of the lamina propria and is made of ligaments28.
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Layer 3: Body- includes the vocalis (thyroarytenoid) muscle28.
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The different layers of the vocal folds have varying properties, and some are more elastic than others29. The vibration of the vocal folds is passive29. Voicing occurs due to the elastic properties of the vocal folds, the ability of the vocal folds to adduct, aerodynamic principles such as the Bernoulli Effect, and air pressure from the exhaled air stream below the vocal folds30.
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When looking down at the surface of the vocal folds during voicing, a wave is seen traveling across the surface31. This is called the mucosal wave31.
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Functions: The main functions of the vocal folds are:
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To protect the airway during a swallow32.
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To produce voicing32.
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To provide mechanical advantage for pushing and lifting32.
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Viscoelastic Properties:
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Elasticity of the VF tissues allows them to spring back after being displaced from midline during vibration33.
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Viscosity (how well a fluid flows) also impacts their vibration. The superior layer of the lamina propria has low viscosity and flows freely33.
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Viscoelasticity is a combination of these factors33.
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The f0 of the vocal folds is a result of muscles' contraction/relaxation and lung pressure changes34. Contraction of the cricothyroid muscle increases the f0, while contraction of the thyroarytenoid muscle may increase or decrease the f034. Increased lung pressure also raises the f034.
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The slower the rate of vibration, the lower the f035. Mass, length, and tension affect the frequency of the vocal folds35. The longer and thicker the vocal folds, the lower the pitch35. As the vocal folds are stretched, they have less mass per unit of length36. The greater the mass, the slower the motion36. When vocal folds are stretched long, they are more tense, which results in greater stiffness37.
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Stiffness is the amount of force required to displace an object (vocal folds) from equilibrium38. The greater the stiffness, the greater the force required to displace it, and the quicker it travels back to equilibrium38.