Sound Waves Resonance Flashcards
What are traveling waves?
Transverse medium- string
Consider a wave on a string
When traveling waves approach collide there is superposition and interference \
Two types of interference: constructive and destructive
What is the reflection string
when one end of the string is secured you get reflection and there is a phase change on reflection
The incident wave and the reflected wave interfere constructively and destructively
What are standing waves
When both ends are secured like a guitar
Waves keep reflecting off ends and you get standing waves ( this is resonance)
Resonance are natural frequencies of vibration
What is a longitudinal standing wave
Air in tube closed at one end, open at other
Very similar concepts to string: incident and reflected waves
But no phase change in pressure at closed end only open end of tube
Constructive and destructive interference, nodes and antinodes and fundamental and harmonics
Describe characteristics of an aproximant
-Most vowel like out of all consonants
-Sometimes called a semivowel and called an approximant given that articulators approach but do not make contact with one another
Types: semi vowel (glide) /w/ and /j/ and liquid
Follow a formant pattern during constriction interval
Key identifying features: Formant transition pattern from the approximant to the ensuing vowel
What is a constriction interval
Represented by a horizontal bar
mark of time period that you are constricting your vocal tract and then releasing it)
how does the formant transition from the approximant to the ensuing vowel differ for each approximant
Formant transition pattern for CV portion of VCV ( for most approximants, the main difference is the F3 transition pattern
Slope index is calculated by changing the F3 divided by the formant transition time
What is a nasal murmur
-Nasal murmur occurs when oral port is closed and VP port is open in nasal consonants):
Source- voice is complex quasi periodic source and located at the end of the tube
What are other characteristics of a nasal murmur
An example of Nasal murmur would be a child with cleft palate
Filter( different): Mouth end of the tube is closed and VP
port is open called shunt resonator
Filter Properties: Resonances- can also call them formants however that term is usually reserved for vowels or poles
What are Antiresonances
AKA antiformants and also called zeros ( white space)
Closed spaces ( closed oral cavity and sinuses ) Large enclosed spaces is low frequency and small enclosed spaces is high frequency
Are sharply tuned vs troughs which are at least as broad
Describe nasals
properties
Occurs for nasal consonants and results in low frequency resonance, antiresonances and higher formants have less energy than vowels
Higher formats have less energy than words
