Sound Theory Flashcards
In humans, what is the audible range of frequencies?
20Hz-20kHz.
What is the speed of sound in air at normal temperatures?
343.2m/s.
A hall being used for music recordings has its gallery supported by square-sectioned pillars. These are 0.5m by 0.5m cross-section. What frequency range of sound will be reflected from each pillar?
Above roughly 700Hz.
A note has a frequency of 200Hz. What is the frequency of the note an octave above?
400Hz.
A note has the frequency of 200Hz. What is the frequency of the note an octave below?
100Hz.
What is the wavelength of a 40Hz sine wave?
8.58m.
How do you calculate wavelength (λ)?
Wavelength (λ) = Velocity (v) / Frequency (f)
How do you calculate frequency (f)?
Frequency (f) = Velocity (v) / Wavelength (λ)
When does diffraction occur?
Diffraction only occurs to a significant effect if the wavelength is greater than the dimensions of the obstacle (the dimensions as ‘seen’ by the waves).
What is power (P)?
Power is the rate at which work is done or at which energy is produced or consumed.
What is intensity (I)?
Intensity is the power falling on, emitted by, or passing through a specific area.
What is pressure (p)?
Pressure is the force acting on a unit area.
What is the decibel (dB)?
The decibel is a unit of comparison of two powers, pressures, voltages, etc.
What is the dB(A)?
The dB(A) is a reasonably good approximation to most people’s assessment of loudness.
What is a the fundamental frequency in a musical sound?
The fundamental frequency in a musical sound is the lowest frequency.
