Lesson 2 - Chapter 2: Sound Flashcards
Sound waves in the natural world are analog. What is analog?
Continuously variable
To record sound, a computer has to do what?
convert the analog input to digital format through sampling
What does sampling mean?
capturing the state/quality of a sound wave a set number of times per second
What is sampling rate measured in?
kilohertz (KHz)
units of thousands of cycles per second
[the more often a sound is sampled per second, the truer the reproduction of that sound]
Amplitude is another word for what?
loudness
What is frequency?
how high or low a sound’s tone is
What is timbre? (pronounced “tamber”)
differentiates the same note played on different instruments
What is bit depth in terms of sounds?
the number of characteristics of a particular sound captured during sampling
(like color depth, the more bit depth used to capture a sample, the more characteristics are re-created)
16-bit sample = captures 216 different characteristics
What is it called when you capture a single track or two tracks?
Single = monoaural
Two = stereo
What makes a sound “CD quality”?
When it’s captured at 44.1KHz with 16-bit depth and in stereo
Pulse Code Modulation [PCM] (1960’s telephone calls) is now known as what format today?
WAV (“wave”)
Why are WAV files stored as compressed MP3?
due to the file size issue of WAV
What is bit rate?
the number of bits per second the sound file uses that determines its (compressed) quality
For MP3, what bit rate is “passable” and what is considered high-quality?
passable - 96 Kbps (kilobits per second)
HQ - 256 Kbps
(uncompressed WAV has a bit rate of 1411 Kbps)
What are codecs?
the code instructions that do the compression
(MPEG-1 Layer 3 codec = MP3)
