In order to understand what we are doing in this lab, it is helpful to go through some terminology and learn about sound and how it is stored. Once you understand a little about sound, we will record sound using a Zoom H4n device and edit it using Adobe Audition.
2.1 What is Sound?
The answer to the question of, "what is sound?" is really a physics answer. Have you ever struck a tuning fork and placed it in water or dropped something in water? If you have, you would have seen waves. Sounds are waves in air, which are picked up by sensors in our ears. Because sounds are waves, let us take a look at a basic sine wave (which we would hear as pure single tone).
cycle. Take a look at the graph and notice that there is one "up peak" and one "down peak". The completion of the up and down "wave" is one cycle.
amplitude. Notice how the graph starts at 0 and goes up to 1 and eventually goes down to -1. The distance from zero to the greatest (or least pressure) is the amplitude. In the diagram above, the amplitude is 1. "In general, amplitude is the most important factor in our perception of volume: if the amplitude rises, we typically perceive the sound as being louder" (page 147, Computing and Programming in Python, A Multimedia Approach by Mark Guzdial)
frequency. How often a cycle occurs is called frequency. Frequency is measured in cycles per second (cps) or Hertz (Hz). Frequency and pitch are related: the more cycles, the higher the pitch.
Questions:
Would the following diagram represent a sound with a higher or lower pitch than the original sine wave diagram?
Would we perceive this sound to be louder or quieter than the original sine wave diagram?
The sounds that we hear are not typically pure tones: they will be composed of waves of different frequency. When you are looking at sound waves in the following sections, you will see more rough edges than the smooth and regular sine waves. This is the result of several frequencies combining together.
1.2 How is Sound Stored?
If you want to capture a sine wave such as the above, you could use an array. For instance taking a sample at (π/2)t, your array would look something like this:
0
3
0
-3
0
3
0
The resulting "wave" would look very triangular. Ideally, more samples could be taken. However, you can understand the idea of representing the wave.
Two questions come in to play when storing sound:
What is the maximum amplitude to be stored? This will determine how many bytes in memory you will use for each sound sample or array element. For instance, if you want to capture amplitudes from 32 767 (215-1) to -32 768 (-215), then you will need 16 bits (2 bytes) for each element.
How many samples or array elements will you have for every second of recording? For instance, the array above could have more samples to "smooth" the wave. The rate at which samples are collected is the sample rate. Some typical sample rates are below:
For CD-quality sounds: 44 100 samples per second. That means that one minute has 60 x 44 100=2 646 000 elements.
Our telephone is designed to capture 8 000 samples per second. That means that one minute has 60 x 8 000=480 000 elements
Now that you understand a little more about sound, let us dive in with doing some recordings and editing.
3. Zoom H4n
Quick start guide on how to create your first recording:
More about levels, auto level (for levelling recordings with different soft and loud voices), comp/limiter (for evening out the soft and loud parts of one voice), get rid of wind noise, and more: https://www.youtube.com/watch?v=OwYZ3CwtxS8
If your audio is "clipping" (ie. the levels is showing up in the red and
your vocals are distorted), you should adjust your volume. Likewise, if
your recording is too quiet, you should also adjust your microphone
volume
There are Audio Files available in YouTube. If you sign into your google
account and go to: https://studio.youtube.com/, you will find on the left "Audio library"
Python Code and Concepts from: Computing and Programming in Python, a Multimedia Approach, by Mark J. Guzdial and Barbara Ericson (Chapters 6 and 7)
8. Exercise
Record a short poem, nursery rhyme, or story (around 20-30 seconds). Using Audition, add 3 additional sound recordings to tell your story.
Some sample nursery rhymes are here
8.1 Your submission:
Add an entry into your learning journal. Your submission should contain:
A heading/project name for Lab 5 and a brief description of what tool was used and what you did (ie. for this lab, it might be something like Lab 5: Audition Nursery Rhyme)
One image of your final Audition work environment with all the tracks(use Command-Shift-4 and space on a mac to take a snapshop of your Audition window). If you do not have a picture of your Audition work environment
(and all of your tracks),
I may withhold your marks until you show me your Audition work environment in the lab.
A link to your finished audio that you've uploaded to SoundCloud: https://soundcloud.com
. Because we are using Behance this semester, you can upload your file to Behance instead. Please note that it seems to take awhile to show up in Behance.
A learning journal entry which will contain:
a heading image that summarizes your project
a description, which contains the goal of your project or the "why are you doing it"
a story, which describes the process that you went through to complete your project. This can be the different stages that your project went through.
design info, which indicates what you used to complete your project. For illustrator, this could be colours and font used. For photoshop, this could be images used. For audition, this could be sounds used.
gratitude. Thank the reader and give credit to any sources of video, audio or images that you have used
