Final Cut X Ripple 2 SOUND Flashcards
When a guitar string is plucked, or someone calls your name, ___ _________ are pushed together….
air molecules
When a guitar string is plucked, or someone calls your name, air molecules are pushed together, raising ___ ________
air pressure
These molecules under pressure ____ other nearby air molecules
push
As these high-pressure waves move through the air, low pressure areas follow, creating a series of _____ and _______
peaks and troughs
When these pressure waves reach our ears, they vibrate receptors, and we hear the vibrations as _____
sound
Looking at this simple waveform, the zero line represents the air pressure at ____.
rest
When the the wave rises above the line, this is higher ________
pressure
….and when the wave drops
below the line it represents lower ________
pressure.
_________ is the term used to describe the change in pressure from the highest peak to the trough
Amplitude
High amplitude waves are ____, low amplitude waves are ____.
loud, soft
_____ is used to describe a single repeated sequence of pressure change, from zero pressure to high pressure to low pressure and back to zero again.
Cycle
_________ is used to describe the number of cycles per second and is measured in hertz.
Frequency
A 1000 Hz waveform for example, emits 1000 ______ per second.
cycles
The higher the _________, the higher the pitch.
frequency
When two or more sound waves meet, they ___ __ ________ from one another.
add or subtract
If their peaks and troughs are perfectly in phase, each waveform is combined to produce a higher _________ waveform
amplitude
If their peaks and troughs mirror each other, the sound wave is said to be out of phase, they cancel each other out, resulting in no _________ and therefore, no sound.
amplitude
Generally, sound waves are out of phase in varying amounts, resulting in a combined ________ that is more complex than individual waveforms. When different sounds are combined like music, voice, background noise and so on, you get a more complex waveform.
waveform
In the analog world, sound is recorded as positive and negative _______ changes.
voltage
For example, speaking into a microphone, high pressure _____ become positive _______, and low pressure _____ become negative _______.
waves, voltage
These voltage changes are stored on tape as changes in ________ _______..
magnetic strength
When the tape is played back, the reverse happens: positive/negative _______ gets converted back into _____ ________, and vibrates the speaker cone to produce the sound.
voltage, sound pressure,
Unlike analog storage media like tape, computers store audio digitally, converting the sound waves into a series of _____ and ____
zeros and ones
In digital storage, the waveform is broken down into individual snapshots called _______
samples
The sampling process is often referred to as __________, or _ to _ __________.
DIGITIZING, A TO D CONVERSION.
The ______ ____ determines the number of digital snapshots of the waveform.
sample rate
The higher the sample rate, the more the digitized audio will faithfully reproduce the original analog ________.
waveform
Low sample rates, on the other hand, limit the number of ____________ that can be recorded, and results in poor quality audio.
frequencies
To reproduce a given frequency, the sample rate must be at least twice that _________.
frequency
For example, songs that you download from iTunes have a sample rate of 44,100 _______ per second, so they can reproduce ____________ of up to 22,050 Hz, which is just beyond the limits of human hearing.
samples, frequencies
When you record audio to your camera, or to a separate digital recorder, the A TO D CONVERSION happens in the ______.
device
When you record audio into your computer from a connected mic, the A TO D CONVERSION happens in the ________.
computer
___ _____ determines DYNAMIC RANGE.
BIT DEPTH
BIT DEPTH determines _______ _____.
DYNAMIC RANGE
DYNAMIC RANGE can be described as the difference between the _______ and _______ sounds in a WAVEFORM.
SOFTEST, LOUDEST
When a SOUND WAVE is SAMPLED, each sample is assigned an __________ _____ closest to the original sound wave’s amplitude.
AMPLITUDE VALUE
When a _____ ____ is SAMPLED, each sample is assigned an AMPLITUDE VALUE closest to the original sound wave’s amplitude.
SOUND WAVE
When a SOUND WAVE is _______, each sample is assigned an AMPLITUDE VALUE closest to the original sound wave’s amplitude.
SAMPLED
A 16-bit audio file, for example, will produce roughly _____ amplitudes
65,000
Whereas an 8-bit audio file will produce only ___ amplitudes.
256
The higher the ___ ____, the more faithful the sound it to the sampled sound.
bit rate
For most video production work, __-___ audio is more than adequate to maintain sound fidelity.
16-bit
.AIFF, which stands for _____ ___________ ____ ______, is a MAC OS file format designed for storing uncompressed audio data.
AUDIO INTERCHANGE FILE FORMAT
The windows equivalent to the .AIFF file type is a .___ file
.WAV
Other audio formats, like .___, .___, .___, are highly compressed formats, and are generally used for delivery, and not for production.
aac, .mp3, and .mp4
1 Hz = 1 ?
Cycle
