Sound

Question 1

.AIFF

Answer 1

Audio Interchange File Format

-a standard digital audio file on the Macintosh and some windows computers.

Question 2

.AU

Answer 2

-a digital audio format popular on the internet.

Question 3

.WAV

Answer 3

-a .WAV sound file is most often used on the Windows platform.

It is also acceptable on the Macintosh.

Therefore it is a good choice for cross-platform compatible sound files. We will use .WAV files for some sounds on our multimedia projects.

Question 4

QuickTime Sound-Only Movie

Answer 4

-the QuickTime format, most often used for digital video, is also an efficient method of digitizing sound.

We will use QuickTime sound-only movies for longer sounds in our multimedia project

Question 5

Compressed Sound

Answer 5

• a sound file that has been altered so that it requires less memory.
• Compressing a sound always reduces sound quality.
• Generally, the higher the compression ratio, the lower the sound quality.
• We will not be using compressed sounds in ourmultimedia project.

Question 6

Decibels (dB)

Answer 6

• Units for measuring sound level differences.

Question 7

Sound Quality

Answer 7

• Determined by the “sampling rate” the “sampling resolution,” and the “compression ratio” of a sound.

Question 8

Sampling Rate

Answer 8

• The number of sampling intervals per second used to capture a sound when it is digitized.
• The higher the sampling rate, the higher the quality.
• The Macintosh (as well as audio CDs) are capable of sampling at 44,100 cycles a second

Question 9

Dynamic Range - Determined by the sampling resolution

Answer 9

The difference between the loudest sound and the softest

sound that can be recorded without distortion.

Question 10

8-bit sounds

Answer 10

• Sounds that have a dynamic range of 48 dB

Question 11

16-bit sounds

Answer 11

• Sounds that have 96 dB.

* Human hearing ranges from silence to 120 dB.

Question 12

Downsampled Sound

Answer 12

• A sound that has been converted to a lower sampling rate.

- Decreases the memory required to store the sound, but reduces sound quality.

Question 13

Waveform

Answer 13

• A graphic representation of a sound.

- The height of the waveform represents the amplitude, or loudness.

Question 14

Amplify

Answer 14

• To adjust the strength or loudness of a sound.

Question 15

Amplitude

Answer 15

• The strength or loudness.

Question 16

Wavelength (period)

Answer 16

• The distance between two successive peaks in a waveform.

- The number of wavelength per second is the “frequency.”

Question 17

Frequency

Answer 17

• The number of wave peaks or cycles in one second.
• Specified in hertz (Hz) or kilohertz (kHz),
• Also know as “Pitch” when applied to our perception of
  sound.