1. Radio production worktext

2.  Analog to Digital  Analog signal – continuously variable electrical signal whose shape is determined by the shape of the sound produced.  An electromagnetic representation of the sound wave can be stored on electromagnetic tape.  Mic>sound pressure>changes in voltage strength>mic cable>recorder>records changes as changes in magnetic strength  Resource  http://www.adobe.com/products/audition/pdfs/a udaudioprimer.pdf http://www.adobe.com/products/audition/pdfs/a udaudioprimer.pdf

3.  All analog measurements are on a continous line with no discreet points.  Like drawing a line on a graph  Reproduction of this signal can lead to generation loss

4.  Digital records the audio waveform as a series of samples consisting of discreet on and off points recorded as binary numbers.  Computers associate these binary numbers to letters of the alphabet and numbers, then computers manipulate these binary numbers.  Analog to digital – analog can be converted to digital by the following four stages:  Filtering  Sampling  Quantizing  Coding

5.  Audio Sound passes through filters  Low pass: eliminates high freqs above human hearing  Can be aliased or anti-aliased back into human hearing range  Audio is sampled many times per second  Converted to (stored as) binary data  Sample rate  32khz, 44.1 khz, 48khz  Sample rate must be twice the highest audio frequency to ensure high quality encoding  Sound frequency example video:  http://videos.howstuffworks.com/hsw/19064-exploring- sound-frequency-explained-video.htm http://videos.howstuffworks.com/hsw/19064-exploring- sound-frequency-explained-video.htm

6.  Quantizing and coding  Makes amplitude samples into manageable, discreet numbers  Bit depth is the max number of “steps” or levels between measurements/conversions  1-bit = two steps (on or off)  16-bit = 65K+ values  Higher bit-depth = higher fidelity  Coding assigns binary numbers to quantized samples

7.  Computer based  Plus some peripherals  2-track vs. multi-track software/hardware  Some systems have both  PCI-slot audio card  USB I/O device  Software  Pro tools, audition, logic, sound forge, audacity

8.  Sound files  Ability to mark a region

9.  Non-destructive editing  Multi-track recording  Transport controls  Timeline

10.  Digital Audio Workstations  Computer  Hard drive  Software interface  I/O hardware  Examples  Pro tools, Logic  Software that work with off-the-shelf hardware  Cakewalk Sonar, m-audio ozone (pro tools m- powered)

11.  Timing of reading audio “words” to a common clock to avoid pops and clicks when switching between unsynchronized audio sources  MIDI (musical instrument digital interface) – allows digital audio equipment to communicate (“talk” to each other)  SMPTE (society for motion picture and television engineers) – timecode  00;00;00;00 = hours;minutes;seconds;frames

12.  Improved audio signal quality  Superior tech specs  Frequency response  Signal to noise ration  Reduced wow and flutter  Non-destructive editing  Copies of edits  Undo  Easy edits and effects  More time and energy spent on creative  metadata

13.  Learning curve  Loss of “warm” sound  Equipment noise  Fans, HDs

14.  DAWs  Production  On-air playback  Logging  bookkeeping

15.  Sound signal  Produced naturally, such as a voice or an instrument  Audio signal  Produced from an audio device such as a recorder, computer, or MIDI

16.  Sound defined Sound defined  Sound is a mechanical wave which results from the back and forth vibration of the particles of the medium through which the sound wave is moving. If a sound wave is moving from left to right through air, then particles of air will be displaced both rightward and leftward as the energy of the sound wave passes through it. The motion of the particles are parallel (and anti-parallel) to the direction of the energy transport. This is what characterizes sound waves in air as longitudinal waves.mechanical wavelongitudinal waves

17.  Resources Resources

18.  Volume measured in decibels  Frequency = pitch; faster = higher  Cycles per second measured in hertz and kilohertz  Pure tone is a sine wave  Without overtones  Fundamental  Voice waveform with timbre, or combination of many fundamentals