Sound 1 Flashcards
(31 cards)
What is sound?
- Sound waves are variatons of pressure traveling through a medium.
- They are created by vibrations from an object.
- The waves then travel from the object to the ear, through air, causing the eardrums to vibrate.
What is Audio?
Audio is the reproduction of sound.
*specially the sound range that is dectable to the human ear.
20 Hz - 20 kHz (20,000 Hz)
What are the properties of a sound wave?
- Wavelength
- Frequency (Hz)
- Amplitude (dB)
- Velocity
Define Wavelength
The distance traveled by a sound wave in one cycle.
Define Frequency.
The number of times the wavelength occurs in one second.
Human range: 20 Hz - 20 kHz
Define Amplitude
The maximum displacment from the center line.
Volume is subjective to the listener.
Define Velocity
The speed at which the sound wave is moving.
Define Timbre
The tone-colour or tone quality of a sound. It is how we identify the difference between the quality of tone of one instrument/voice from another
Use the frequency specturm to define your timbre or “tone quality”
Define Space
The interaction between the environment and sound source will create alteration to the sound.
Peak
Measurment of the maxium positive or negative signal level of the wave
Peak-to-Peak: total measurment of positive and negative peak.
RMS
Root Mean Spuare
A measurment of how we hear
Compression
A high value on sound wave. increased air pressure.
Rarefaction
Low point on a sound wave. Air molecules are spread out.
Fundamental
Lowest frequency of a sound.
Ex 440 Hz
Harmonics
A integer of the fundamental.
(integer is a whole number)
Ex: 440 Hz x 2 = 880 Hz
880 Hz is a Harmonic of the fundamental.
Overtones
Frequencies that are not integers of the fundamental.
Ex: 440 Hz x 0.5 = 220 Hz or 440 Hz x 1.5 = 660 Hz
440 Hz and 660 Hz are overtones of the fundamental.
Formants
Frequencies that do not alter with relation to the pitch being produced.
Subharmonics/Subtones
Frequencies that are below the fundamental frequency
Acoustic World
The world we live in! Everything we hear is acoustic energy.
Measured in SPL
0 dB - 140dB
Analog World
Occurs when an audio signal is turned into an electrical signal via mic, line, or instrument.
(Has Headroom)
Signal is in the analog world as it’s running through the cable.
-infinity - 0 dB
Digital World
When the audio signal is transduced via a analog-to-digital converter.
(no headroom)
froms 0s and 1s to a waveform.
Attack
The time it takes a signals inital transient to reach full volume.
1st stage in acoustic envelope
Decay
The time it takes a signal to drop from the height of the attack level to its sustained volume.
2nd stage in acoustic envelope
Sustain
Time from end of decay to the release.
3rd stage in acoustic envelope
