Psychoacoustics Flashcards
What is frequency?
Cycles per second, Hertz (Hz)
What is a cycle?
One full repetition of the condensation and rarefaction of the molecules.
What is frequency percieved as?
Pitch.
What is the range of human hearing in Hertz
20 - 20,000Hz
What is a period?
Time taken to complete one cycle.
Period and Frequency have an inverse relationship, meaning…
As frequency increases, the period decreases (and vice versa). When freq. doubles, period reduces by half.
Formula for Period (T)
1/f in Hertz
Formula for Frequency (f)
1/T in seconds
What symbol represents wavelength?
λ (lambda)
What is a wavelength?
Distance of a pure tone traveled in one cycle
Wavelength and Frequency are inversely proportional meaning…
Higher frequencies have shorter wavelengths; lower frequencies have longer wavelengths.
What is Starting Phase?
The starting point at which a cycle of vibration begins.
What is constructive interference?
[When adding waves together] When phases match up with each other.
What is destructive interference?
[When adding waves together] When phases are out of phase (line).
What is Amplitude?
The magnitude of a sound or how much the molecules are being displaced.
What is Amplitude perceived as?
Loudness
What is Intensity?
Related to the volume or amplitude of a sound or waveform
What is Sound Pressure?
Measure of force distributed over an area.
What is a Decibel?
A logarithmic unit (by 10s) to describe intensity of a sound made by Alex Bell.
What is the Threshold of the Audibility Curve?
A graph that shows the dB SPL needed for the average human ear to detect a sound at a given frequency
What does Threshold mean?
The softest sound (lowest intensity) a person can hear (perceive)
What are complex sounds?
Anytime there are 2 or more pure tones, this is a complex sound. They have periodic vibrations.
What is a pure tone?
Simple periodic vibrations.
What are aperiodic sounds?
White noise or static. Or voiceless speech sounds.
