Resonance and Vibration
Identify the difference between a node and an antinode
Node = points along a wave that vibrate with minimum amplitude, happens at the closed end of tubes
Antinode = points along a wave that vibrate with maximum amplitude/pressure change
The relationship between amplitude and intensity.
What is intensity is proportional to the square of amplitude
What is a logarithmic relationship
What is greater intensity and amplitude = louder sound
Define formant.
What is resonances of the vocal tract
Define constructive interference
What is waves that combine and increase the amplitude of the resulting wave
Define low-pass filter
An acoustic resonator that filters out higher frequencies
Define a standing wave.
A wave pattern that appears stationary because two waves of the same frequency travel in opposite directions and interfere with each other, creating fixed points called nodes and areas of maximum movement called antinodes.
Sound that a pair of normal hearing ears can detect 50% of the time under ideal listening conditions; represented by 0 dB.
What is threshold of hearing
Describe what determines F2
What is length of the oral cavity and tongue advancement
Describe how temperature affects a sound wave
What is refraction towards cooler air
Describe the threshold of pain.
What is an intensity level of 130 dB that causes pain in the ears.
List the types of resonators we have discussed in class.
Helmholtz Acoustic Resonator = vibrating container filled with air
Half-wave resonator = tube open at both ends
Quarter-wave resonator = tube closed at one end
Reference sound in dB scale for intensity.
What is 10-12 W/m2
What is 10-16 W/cm2
Describe 4 major characteristics of the resonator of the human vocal tract
What is a quarter-wave resonator, series of resonators connected to each other, broadly tuned resonator, and variable resonator
Describe how an echo occurs.
What is when an incident wave vibrates the eardrum but the eardrum has time to stop vibrating before it is set into motion again by the reflected wave
What is a reflected wave is heard as a separate sound
The point on a resonance curve where the intensity has decreased to half its maximum value.
What is half power point
The difference between a half-wavelength resonator and a quarter-wavelength resonator.
Half-wave resonator = tube open at both ends, fits half a wave
Quarter-wave resonator = tube closed at one end, fits a quarter wave
Reference sound in dB scale for amplitude.
What is 20μPa
What is 0.0002 dynce/cm2
What is 0.0002 μbar
Describe the relationship between vowel height and F1.
What is high vowels, low F1 and low vowels, high F1
The two locations in a standing wave where the air particles experience either maximum or minimum displacement.
What is nodes and antinodes
The range of frequencies humans are capable of hearing.
What is ~20-20000 Hz
The resonant frequency of a 0.25 m quarter-wavelength resonator when the speed of sound is 343 m/s.
What is 343 Hz
(fundamental frequency = speed of sound/4*length)
(Hz=343/4*0.25)
Occurs to intensity when a 1 dB change occurs.
What is a 26% change in intensity
What is the smallest change in sound intensity that can be detected by someone with normal hearing
Describe how vowels with the tongue in the back position affect the oral cavity and resulting F2.
What is results in lengthened oral cavity and lower F2.
The difference between free and forced vibration.
Free vibration occurs without a continuous external driving force, while forced vibration is caused by a continuous external force
List five aspects of a decibel (dB).
1. involves a ration
2. uses a logarithm
3. is nonlinear
4. is expressed in terms of various reference levels
5. is a relative unit of measure, not a discrete one