Lecture 1 Flashcards
Frequency
The number of oscillations/cycles in a given unit of time
To what range of frequencies is the human ear sensitive?
20 - 20,000 Hz
Fundamental frequency
The lowest frequency at which a particular object naturally vibrates (e.g. an individual’s vocal cords)
Periodic sounds
Sounds that have regular oscillating patterns of compressions and rarefactions
Aperiodic sounds
Sounds that do NOT have a regular oscillating pattern; i.e. “noise”
Complex sound wave
Consists of more than one frequency. Each complex wave is the combination of simple simple sine waves or “pure tones”
Wavelength
The distance traveled by one cycle of the waveform
Phase
The starting point of a cycle with respect to another tone. Sounds are “in phase” when they begin their cycle at the same time
Amplitude
The degree of change (positive or negative) in atmospheric air pressure caused by the sound waves. Directly related to the acoustic intensity of the sound
What is the difference between decibel IL and decibel SPL?
Decibel IL measures the intensity level (i.e. energy - therefore measured in watts) and decibel SPL is a measure of the sound pressure level in pascals
Spectral analysis
The process of analysing any complex waveform into its simple sinusoidal components
Harmonics
A whole number multiple of the fundamental frequency
Pitch
The psychological correlate of the fundamental frequency of a periodic sound wave
Loudness
The psychological correlate of the amplitude of a periodic sound wave
Sone
A psychological SCALE of loudness. As sound intensity increases, the human perception of loudness also increases (but more slowly). That is, as the sound gets louder, the human ear needs a progressively greater and greater change in intensity to perceive an equal degree of loudness change
