CDO 463 3 Resonance
Card Set Information
CDO 463 3 Resonance
Basic Acoustics Resonance
String vibrate at
even and odd multiples
Tubes vubrate at
object vibrating at its natural frequency
ex) tuning fork, string, column of air in a tube closed at one end
Natural frequency is determined by
length, mass, and stiffness of an object
using on vibrating system to cause another to vibrate
ex) holding a tuning fork on a table - forcing it to vibrate
the energy being supplied (tuning fork)
the system to which the energy is being supplied (table)
Will every driving force make the driven system vibrate?
Resonance is all about
the frequency of the driving force and the natural frequency of the driven system
when the frequency of te driving force is at or near the driven system
the closer the frequency of the driving force is to the natural frequency od the driven system...
the lower the amplitude of the forced vibration
Resonance curves (frequency response curves) show the relationship between
the frequency of the driving force and the amoplitude of forced vibration.
Peaks of amplitude occur when
the frequency of the driving force matches the natural frequency of the driven system (resonance).
high amplitude of forced vibration, restricted range of frequencies resonated
low amplitude of forced vibration, broad range of frequencies resonated
Is the vocal tract highly or lightly damped?
What can be resonated?
Anything that can vibrate
Examples of air-filled resonators
simple Helmholtz resonator
double Helmholts resonator
What are important characteristics of air filled resonators?
length of neck
Which example if an air-filled resonator is a model for the vocal tract?
Double Helmholts Resonator
In the double Helmholtz resonator,
l1 and A1 represent
l2 and A2 represent
In tube vibration f0, f3, f5 correspond with
fo = F1
f3 = F2
f5 = F3
In string vibration, f0, f2, f3, f4 correspond with
f0 = F1
f2 = F2
f3 = F3
f4 = F4
The resonant frequencies of the air-filled tube will match the..
natural frequencies of the tube when pulsed
Perturbation theory describes
the effects of constriction, or perturbations, on the resonant frequencies / quality of sound of the tube
Pertrbation theory explains that
constriciton near antinodes decrease resonant frequencies
constriction near nodes increase resonant frequencies
The tube will resonate frequencies that
match its natural frequencies
opposite sid eof the rsonator coin
resonation looks at the
output in terms of the frequencies that are enhanced
filters look at
the output in temr of the frequencies that are absorbed or reduced in energy