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Speech Sci Test 1
Speech & Hearing Science
Question | Answer |
---|---|
What is sound? | Sound occurs when a disturbance creates change in air pressure |
What causes the disturbance? | Some type of movement: human vocal folds opening and closing |
How are pressure changes transmitted? | The pressure changes are transmitted through the medium and are perceived as sound. |
How can the fundamentals of sound be defined in terms of components? | Medium: Air; Vibrating Mechanism: Vocal Folds; Force: Pressure (subglottal); Receiver: Ear |
Describe Brownian Motion | Air is a gas made up of many molecules constantly moving in random patterns at high speed. As the air molecules move around they collide with each other and whatever is in their path. This collision produces pressure. |
How is air pressure measured? | Pressure can be measured in various ways that incorporate the Force exerted and the Surface Area on which the force is acting. |
What are the units of measurement for speech? | Dyne: The pressure needed to move the eardrum. Force per sq cm. For smaller surface areas. Pounds: Larger amounts of force. Force per sq. inch. |
What is the MKS system? | M=meters; K=kilograms; S=seconds (distance, mass, time). Uses Newton per square meter to measure force = Pascal. |
What is the CGS system? | C=centimeters; G=grams; S=seconds (distance, mass, time). Uses dynes per square centimeter = Microbar. |
Hearing measurements use what? | Micropascal |
What is pressure that is higher than Atmospheric Pressure called? | Positive Pressure |
What is pressure that is lower than Atmospheric Pressure called? | Negative Pressure |
What is Equilibrium? | The natural tendency for air to move from an area of high pressure to an area of low pressure? |
What is Air Flow? | Movement of air through a particular area in a certain time interval. |
What is Volume Velocity? | The rate of the flow; how fast the gas is flowing in a certain direction. |
What is Driving Pressure? | Differences in air pressure causing air to flow from high pressure to low pressure. |
What is volume? | The amount of space occupied in three dimensions? |
What is density? | The amount of mass per unit of volume. |
What is Boyle's Law? | As volume increases, pressure decreases; As volume decreases, pressure increases. |
Summarize Compression and Rarefraction. | Air molecules that are displaced due to disturbance in pressure do not travel to a listener's ear, BUT the vibration (disturbance) that causes the changes in air pressure is what generates the sound. |
What does the Vibrating Mechanism do? | Causes the disturbance and in turn begins to create the changes in pressure. |
What is Compression? | An area of high pressure; Occurs when air molecules approach and collide with an area of high pressure. |
What is Rarefraction? | An area of low pressure; Occurs when air molecules approach and collide with an area of low pressure. |
What's Ambient Air Pressure? | Relatively constant pressure that must be disturbed to create sound. |
The basic nature of sound consists of what? | Alternating increases and decreases of Ambient Air Pressure. |
Compressions and Rarefractions continue to radiate out and back due to what? | Elasticity, Inertia, and Amplitude |
What is Elasticity? | Restoring force (ex: rubber band)). Hook's Law. |
What is Inertia? | Tendency of a mass to remain at rest or in motion unless acted upon by an outside force. (ex: swing) |
What is Amplitude? | The maximum distance away from the rest position that the molecule is displaced. Determined by the amount of force. How far the molecules are displaced. |
What are the characteristics of sound waves? | Frequency, period, wavelength, amplitude |
What is the cycle of vibration? | One back and forth movement of the molecule. |
What is Frequency? | The number of cycles per second at which an object vibrates. |
What is the unit of measurement for frequency? | Hertz |
How many cycles occurring per second does a 1000 Hz sound wave have? | 1000 |
What would be a "low" frequency? | 100 Hz |
What would be a "mid" frequency? | 1000 Hz |
What would be a "high" frequency? | 4000 Hz |
What things vibrate at 100 Hz? | Tuning fork, air molecules, and eardrum |
What is the Period? | Time it takes each cycle to occur. Symbolized as "t". |
What's the formula for Period? | F = 1/t (F = # of cycles per sec; t = time for each cycle) |
In order to better visualize the various characteristics of sound, how do we typically display sound? | Waveforms: A graph with Time on the horizontal axis and Amplitude on the vertical axis. |
What are the 2 types of sound waves (complex sounds)? | Periodic Wave: Wave at which periods (cycles) are constant/equal. Aperiodic Waves: Wave at which cycles are NOT constant/equal. Ex: noises. |
What are Harmonics? | Whole number multiples |
What is Velocity? | The speed of sound; depends mostly on the medium (also temperature, altitude). |
Does sound travel faster through solids and water or air? | Solids and water. |
What is a Wavelength? | Measurement of the travel of sound; the distance covered by one complete cycle of pressure change. |
Describe the direct relationship between Frequency, Period, Velocity, and Wavelength. | The higher (more Hz) the frequency: shorter wavelength. The lower (less Hz) the frequency: longer wavelength. |
What 3 things happens from environmental interference? | Absorption, Reflection, and Interference. |
What is Absorption? | Sound is dampened but still transmitted. Soft irregular shaped materials: carpet, insulation, ceiling tile, soft furniture. |
What is Reflection? | Sound bounces back and travels in opposite direction. Hard smooth materials: wall, hardwood, bathroom tile, tables, concrete. |
What is Interference? | Two or more waves combining. Happens from Reflection. Wave hits something hard and bounces back to hit another wave. |
What are the two types of Interference? | Constructive: Increases amplitude. Destructive: Decreases amplitude; timing is off. |
What is a pure tone? | Wave with only one frequency; smooth wave. |
What is a complex wave? | Waves with more than one frequency. |
What is a Periodic Complex Wave? | Contains multiple frequencies that are related (mathematically) to each other. Rich, resonant quality. Musical instruments/some speech. Includes Fundamental Frequency and Harmonics. |
Lowest frequencies | Fundamental Frequency |
Whole number multiples | Harmonics |
What is an Aperiodic Complex Wave? | These frequencies are not mathematically related to one another. Can't do math to determine the frequencies that make up a sound. No Fundamental Frequency or Harmonics on graph. |
Describe Norms. | They have been developed for many acoustic variables related to human voice and speech production. They are available for different age groups. They offer a starting point for rehabilitation and acoustic measures and strengthen accountability. |
What is a Visi-pitch? | A computerized transducer fitted with acoustic hardware and software. The person speaks into an attached microphone, which changes the acoustic signal into corresponding electrical signals. |
What does the Visi-pitch calculate? | It calculates the Fundamental Frequency and relative amplitude over time. |
What are some Frequency Variables? | Average Fundamental Frequency, Fundamental Frequency variability & range, Maximum phonational frequency range. |
Describe Average Fundamental Frequency. | Measured in a particular task: sustaining a vowel, reading aloud, conversational speech. Averaged over the speaking time of the task. Measured during oral reading or conversational speech task = SFF (speaking fund freq). |
Why do males have lower Fo than females? | Bigger vocal folds + slower vibration of vocal folds = lower pitch |
Male Fo | 120 Hz |
Female Fo | 220 Hz |
Children Fo | 350-500 Hz (thinner vocal folds that vibrate faster) |
Average Fo remains stable in adult males and females until when? | 6th or 7th decade of life |
What methods of assessing pitch are unreliable? | Subjective,perceptual methods |
Fo changes correspond to what? | Frequency variability. |
Too much or too little frequency variability can indicate what? | A functional, organic, or neurogenic voice problem. |
How is Fo variability measured? | In terms of standard deviation (SD) from the average Fo. |
What does the standard deviation of Fo reflect? | The spread of Fo around the average Fo. When this variability is measured in Hz, it's called FoSD. |
What is FoSD in normal conversational speech? | 20-35 Hz |
What is FoSD converted into semitones? | Pitch Sigma |
What is the Pitch Sigma for normal speakers during conversation? | 2-4 semitones for males and females. |
What is range? | The difference between the lowest and highest Fo in a particular speech sample. |
Who has the greatest range of frequencies? | Infants. Their vocalizations contain a lot of non-speech words. |
What is the Fo used in conversational speech from 3 years-puberty? | 150-200 Hz |
From 7 years-adulthood, who uses a wider range: males or females? | Females. Maybe more sociocultural. Can go above Fo by using falsetto or a higher pitch. |
What is Maximum Phonational Frequency Range (MPFR)? | The complete range of frequencies that an individual can generate. Often measured in semitones or octaves. |
What does MPFR reflect? | The physiological limits of the speaker's voice and the physical conditions of the person's vocal mechanism and basic vocal ability. |
What is Average Amplitude? | Refers to the overall level of amplitude during a speech task. Perceptually, this corresponds to the loudness that the individual generates during the speech activity. |
What is the range of normal conversational speech? | 65-80 dB SPL (sound pressure level) |
What is the average SPL for males and females? | 70 dB SPL |
Clinically, a reduced amplitude level is indicative of what? | A speech disorder; difficulty opening the vocal folds widely and closing them. |
What causes Amplitude to vary? | Speaker's mood, feelings, the message being conveyed, stress, accents of syllables and words, etc |
How is Amplitude variability expressed? | As a standard deviation, measured in dB SLP. Usually around 10 dB SLP. Measured 10 dB above and below average. |
What is the reduced ability to vary loudness? | Monotone. |
Dynamic Range relates to what? | The physiological range of the vocal amplitudes that a speaker can generate. Ranges from the softest to the loudest shout. It's related to Fo. |
What should the minimum dynamic range be? | 30 dB SPL (depending on the frequency) |
Dynamic Range is greater and less for what Fo? | Greater for Fo in the midrange and less for frequencies higher or lower than midrange. |
What is the Voice Range Profile (VRP)? | A graph that plots a person's phonational range against his/her dynamic range. |
How is the VRP set up? | Dynamic range is plotted on the vertical axis in dB SLP and Fo is plotted on the horizontal axis in Hz. |
How do you generate the Voice Range Profile? | The speaker phonates a vowel at different Fo levels. At each level, the speaker phonates as soft and as loud as possible. |
What do the upper and lower contours of the VRP show? | Upper: maximum intensity at each frequency. Lower: minimum intensity at each frequency. |
What is the characteristic shape of a VRP? | Roughly oval with narrower endpoints and a more expanded mid-section. |
What is the "dip" in the VRP? | Usually seen in the upper contour at around 390 Hz for men and 440 Hz for women. |
Why do children express a compressed VPR? | Due to reduced dynamic range. |
Is there a difference in VRP between trained and untrained voices? | Yes. |
What are the two types of Aperiodic Complex Waves? | Continuous: hissing noise; longer duration. Transient: short noise. |
Describe the characteristics of sound waves. | Frequency: # of cycles per minute. Period: length of cycle. Amplitude: height of cycle. Wavelength: distance between each cycle. |
How are the characteristics of sound waves depicted? | On a Waveform: a graph with Time on the horizontal axis and Amplitude on the vertical axis. |
What is a Sinusoid? | Smooth shape; pure tone. |
What is it called if all cycles of the waveform repeat themselves in a predictable fashion? | Periodic. |
What is it called if the cycles repeat themselves in the same way but the SHAPE is not Sinusoid? | Periodic Complex Sound. |
What is it called if cycles are different with different amounts of time? | Aperiodic. |
How can you determine the Fo of the Complex Periodic Sound? | By finding the largest peak. |
What CANNOT be seen on a waveform? | Harmonics of a Complex Periodic Sound. |
What is a spectrum? | A graph with frequency along the horizontal axis and amplitude along the vertical axis. |
What is a way to visualize Harmonics? | Line graph. |
What is on a line graph? | Horizontal axis: frequency. Lowest frequency to left, increasing to the right. Vertical axis: amplitude. |
How does a line graph display Fo, each frequency, and its amplitude? | As a vertical line. Height of line = amplitude of that frequency. |
What is not evident on a line graph? | Time. |
How are frequencies shown on a line graph? | At one particular instance at a time. |
Why is a line graph NOT used to represent a Complex Aperiodic Sound? | Because it is a broad band of frequencies. |
Aperiodic Complex Sounds use what? | Envelope of the wave. |
What is a Continuous Spectrum? | A horizontal line connecting all of the component frequencies of the sound. |
What can't you see on a line graph? | The duration of sound; can't tell if it's continuous or transient. |
What is the source of sound? | The vocal tract |
What does the rate of vibration of the vocal folds depend on? | Mass, tension, & length |
Vocal fold Fo is mainly determined by what? | Tension of the vocal folds. |
What happens to female Fo with age? | Gets lower |
What happens to male Fo with age? | Gets higher due to thinning of vocal folds. |
How is intensity controlled? | By regulating Subglottal pressure (Ps). This is done by decreasing and increasing Medial Compression. |
What does increasing Medial Compression cause? | Vocal folds to press together more tightly, causing Subglottal pressure to build up more strongly and when they're blown apart, they blow apart more forcefully and come back together more forcefully. |
What happens to a sound wave that's generated? | It has greater amplitude and intensity which affects the loudness of the sound. |
What happens to the vocal folds during speech? | The vocal folds continuously modify their tension characteristics to change Fo and intensity according to the verbal message. |
What do the changes in Fo and intensity affect? | Prosody (melody), intonation, mood, and emotion. |
What is Minimum Driving Pressure? | AKA: Phonation Threshold Pressure (Pth). For conversational speech: 3-5 cm H2O. |
What is needed for higher Fo? | More pressure is needed to set vocal folds in motion. |
What is needed for louder speech? | Higher pressure (50 cm H2O) |
What is Speech Science? | Concerns the quantitative, instrumental analysis of the anatomical, physiological, and acoustic bases of speech productions and perception, and of the cognitive processes involved in verbal & nonverbal communication. |
What does the study of speech production involve? | It primarily involves the use of systems and instruments for observing and recording respiration, resonance, and speech movements. Ex: vocal fold vibration and tongue movement. |
What does the study of speech perception cover? | It covers auditory capabilities in respect of physical parameters such as loudness and pitch, the relationship between these physical parameters and psychological percepts, & the categorization of speech sounds. |
What does the acoustic analysis of speech concern? | It concerns the physical properties, such as the frequency & intensity of speech sounds. |
What is research conducted in speech science relevant to? | Speech synthesis & coding, automatic speech recognition, human-computer dialogue systems, the medical application of speech & hearing technologies, the study of language acquisition by children and both native and non-native speakers. |
What is Hearing Science? | Speech perception, decoding the speech signal, identification & categorization of contextual and linguistic information, auditory function across a lifespan. |
What are more characteristics of Hearing Science? | Speech recognition & temporal processing, spectral analysis, noise-induced hearing loss, cortical pathways & higher function auditory processing. |