The first step was to download wav files to edit. A quick internet search took me to a website called http://www.wavsource.com which provides internet using with free wav files to download, mainly clips from films.
The task specified to identify four or five, upto 150KB in size. I did accordingly, with the largest of my five being an extract from Apocalypse Now which was 99KB in size and also to note their duration, which were as follows:
- Back to the Future "you can achieve anything" - 5 seconds
- Braveheart "they may take our lives" - 5 seconds
- Apocalypse Now "insane" - 30 seconds
- Cast Away "Wilson" - 12 seconds
- Shrek "Singing" - 5 seconds
I opened up the Cast Away file and played it. In Cool Edit Pro, the sound waves appeared as follows:
By looking carefully, you can see a yellow cursor at the start of the wave. This can be moved by the user. If it is moved and you click play, then the playing will commence from the where the yellow cursor starts. The below image depicts the yellow wave starting further on.
As you can see the yellow cursor is now stationed further along the wave. Another way of noticing that the sound is set to only be partially played is the number underneath the sound. The first image is "0:00.000" whereas the second is "0:06:790" meaning that upon clicking play the sound will be played from roughly 6.8 seconds until the end.
This part of the file can be saved on its own by highlighting the area using the mouse (similar to how you would in a word processing package) and then clicking File > Save Selection. It is crucial to give it at least a slightly different file name, so your first file does not become overwritten. I simply added "_2" to the file name whilst saving, making it "cast_away_wilson_2.wav".
Here is a result of saving the section. The wave now appears in a different shape, and the total duration has been trimmed from 12 seconds to under five seconds.
The task then recommended to try the standard edit commands in cool edit pro:
- Copy
- Paste
- Delete
- Trim
- Select Entire Wave
- Undo
The above wave incorporates the features, cut and paste. By highlighting a wave similarly to how I mentioned before and right clicking, I clicked "cut" I then chose the area I wished the section to now play at. For simplicity reasons, I chose to add it to the end of the file, right clicking and then selecting "Paste", you can audibly hear the difference, as the end of the clip contained music which gave a "fade-out" atmosphere. The edited wave hears the music fade-out, before playing the desired section from the start. I then tested the undo function, clicking "Edit > Undo Paste" followed by "Edit > Undo Cut" which reverted the image to its original state.
I then tested the "Copy" command, taking the same section that I previously "Cut" and again placing it on the end of the file. This time, as I chose "Copy" and not "Cut" instead of the sound being moved to the end of the wave, it's repeated at the start of the wave, now playing twice, increasing the duration from twelve seconds to roughly sixteen. The wave appears as such:
I then attempted the "trim" function next. This function crops a wav file, leaving only the highlighted part and making the rest of the file disappear. This can be handy if you are looking to extract a small part of a file, a single word perhaps. This is how my attempt at trimming appears:
The final command was "select entire wave". This one was fairly self explanatory, it just highlights the entire wave. This can be done by using the edit menu, or by pressing "ctrl" and "a" which is almost universal in computer programs for meaning "select all".
The next task was to "File > Open Append" two other sounds onto one which was originally loaded. Upon doing this, the system highlights to you with red and blue toggle functions where each sound starts and finishes. This basically adds the two files that were imported through the "open append function" to the file which is already open.
By default, Cool Edit Pro measures time in seconds, but I'm going to experiment with a different time measurement. This is done by clicking "View/Display Time", which gives you a list of options. I chose to change from "decimal" (seconds) to "samples"
The waveform itself does not change, but the units of measurement do. In samples, they range from 0 to roughly 55000, where as in decimal the range is from 0 to roughly 50.
Next I explored the different options available in the vertical axis. Below are screenshots of each of the settings for the vertical axis, which depicts the volume of the sound at each point of the wave. The difference in values is visible on the right hand column next to the wave.
1. Sample Values (Default)
2. Normalised Values (Ranging from -1 to 1)
3. Percentage (0% being the minimum, 100% being the maximum)
4. Decibels (dB standard measurement)
For the next part of the exercise, I opted to open another wav file. This part of the exercise required select parts and zooming in and out. The wave appeared as follows without any alterations
Zooming in on a certain section, by using the buttons underneath the wave leaves it looking like this:
This zooms in on the first word in the clip. Words are recognisable in Cool Edit Pro as the parts with high amplitude. Parts with prolonged sections of low amplitude are gaps in speech. Although I was able to determine where the first word would start and finish. I double checked by playing the sound back.
If you zoom in far enough you can see each individual sample as shown below. After exploring this, I zoomed out to give the image its original state.
I then went on to try some effects with the sound, which were as follows:
Invert- brings the amplitude closer together and cut's down on harsh sound between words.
Reverse- plays the sound backwards.
Silence- removes the amplitude of the sound, meaning it appears as silence.
Modifying the amplitude of an image is also a feature of Cool Edit Pro. In its original state, the peak amplitude of the waveform is 100%, by clicking Effects > Amplitude > Constant Amplitude and choosing the 6dB cut option, it decreases the amplitude, making the peak 50%. Both the images are shown below, the original followed by edited one. Having played the second one back, the sound is not quite as loud. Afterwards I boosted the amplification by 3db, which showed a peak of approximately 70% and then added 3dB once again to bring it back to it's original state. The third image is also shown below. The user can normalise the amplitude by clicking Effects/Amplitude/Normalise and you can select a percentage to normalise to.
Fade In/Out
Two other effects of Cool Edit Pro are too "Fade In" the amplitude and to "Fade Out". The former means the sound is edited in a way in which it starts off quietly and increases towards the end. "Fade Out" is the opposite, it's starts loudy but quietens down as the sound progresses. Both are shown below, "Fade In" first, followed by "Fade Out". Notice that in the first one, the higher maximum amplitude is towards the end of the wave, whereas in the second it is fairly close to the beginning.
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