Your SlideShare is downloading. ×
0
An Introduction to Digital Audio
An Introduction to Digital Audio
An Introduction to Digital Audio
An Introduction to Digital Audio
An Introduction to Digital Audio
An Introduction to Digital Audio
An Introduction to Digital Audio
An Introduction to Digital Audio
An Introduction to Digital Audio
An Introduction to Digital Audio
An Introduction to Digital Audio
An Introduction to Digital Audio
An Introduction to Digital Audio
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

An Introduction to Digital Audio

528

Published on

0 Comments
4 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total Views
528
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
0
Comments
0
Likes
4
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. SOUND EDITINGIntroduction to Sound Vilina Hutter, Instructor Digital Communications/49er ROP
  • 2. Sound Waves• Sound is caused by vibrations in the air – Guitar strings, vocal cords, speaker cones• Air molecules are pushed together, causing subtle air pressure changes – Ear drums interpret the pressure changes as sounds• Analog sound waves represent the shifts in air pressure
  • 3. Measuring Sound Waves
  • 4. Amplitude• Distance from the peak to the trough of the wave• The higher the amplitude, the louder the sound
  • 5. Frequency• Number of wave cycles per second• Measured in Hz• The higher the frequency, the higher the pitch
  • 6. Cycle/Phase• Cycle – Single sequence of pressure changes from zero to high to low, and then back to zero• Phase – Position in the cycle – Measured in degrees• Wavelength – Time it takes to complete one cycle
  • 7. Interaction of Sound Waves• In Phase – Waves that are perfectly in phase reinforce each other• Out of Phase – Waves that are perfectly out of phase cancel each other
  • 8. Interaction of Sound Waves• Waves that are out of phase in varying amounts combine to form a more complex wave
  • 9. Recording Sound Waves• Microphones convert pressure changes into voltage changes – High pressure becomes positive voltage – Low pressure becomes negative voltage• Voltage changes can be recorded as changes in magnetic strength on tape for analog recording• Digital recording is done by sampling the analog waveform
  • 10. Sampling• Each sample is a snapshot of the voltage value of the analog wave• The more often the sample is taken, the more accurate the digitization of the sound will be
  • 11. Sampling Rates
  • 12. Bit Depth• Size of each sample• Higher the bit depth, the better audio quality is possible
  • 13. Audio File Formats• Uncompressed – WAV (AIFF on the Mac) • Files can get very large • 5 MB per minute for a mono file at 44,100 sampling rate• Lossless compression – File formats that save space by not recording data for silence – FLAC, WavPack• Lossy compression – Complex algorithms that attempt to reproduce sound using less data – MP3, Ogg Vorbis, WMA (includes DRM), ra, AAC (I-Tunes)

×