Week 4 - Goldwave

This entry will be discussing the use of Goldwave and its various features.

To start off, here is an image of the UI with a sound file loaded into it.

Loading a file into Gold Wave is as you would expect for most software in Windows, by simply clicking on File -> Open and then navigating to the appropriate file. The wave form is displayed in the center in green.

The main display of the sound is little more than a simple chart, with an X and Y axis. In this case, the X axis represents time in hours, minutes and seconds and the Y-axis is a normalized scale ranging from -1.0 to 1.0. In this situation, normalization refers to putting values from one scale into another scale, in this case from 1 to -1 (http://mathforum.org/library/drmath/view/60433.html). You can change what the X and Y axis measure with by clicking Options -> Window. Changes that you make to the Y axis will not alter the waveform (even in the display), only the units that the amplitude is measured with.

This is the control window, which is used for playback purposes. The green play button will play the entire  sound from the current position of the cursor. The yellow play button will play from the beginning to the end of the currently selected portion of the waveform, regardless of the position of the cursor.

This is simply showing what a selected portion looks like. To highlight a part of the sound, simply left click and drag over the portion of the sound you wish to focus on. The yellow playback button will only concern itself with this portion of the file until you de-select it. This is also necessary if you want any edits from simple ones (cut, paste) to more complicated ones (altering amplitude, filters) to only affect a given part of a sound, instead of the entire thing.

You can also save the selection through File -> Save Selection As.

This portion is for control and monitoring of the sound. The top bar is Volume, which is self explanatory. The second is balance, which is to say how much to split the volume between Left and Right. Center is balanced. The third bar is speed, which is again self explanatory. These are all things that can alter the sound while it's playing back, without actually editing the sound itself.

The final bar is the VU meter (Volume Unit meter). This concerns itself with the loudness of the sound at present, the bar itself will push a line which has a delay before it descends back to the left whose purpose is to indicate the peak loudness of the sound. Red indicators are at the left of the bar and will light up if a wave's amplitude is so large that clipping occurs (which means information is lost).

This selection of buttons in the main toolbar control zoom levels. The left-most is "View All", which will fit the entire sound into the available window space. The second button, "View Selection", zooms until the current selection fits within the available window space. Previous Zoom just returns to the last zoom setting. Zoom in and Zoom out are self explanatory. Zoom 1:1 will zoom the view up so that each pixel on the screen represents 1 sample. (http://hbkurs.gymnasium.sundsvall.se/HB_05_Le_mum1210/lj87togr/Projekt%20X/GoldWave/GoldWave.htm#Zoom 1:1).

Effects of Inverting and Reversing

The Effect menu has a number of functions in it, but this section will only concern itself with the effects of two of them. A particular part of the wave form is selected for the purpose of this.

After applying the invert effect (Effect -> Invert), the wave now looks like this:

Visually, the wave is quite different. However, it doesn't actually sound any different. This is because all invert does is alter the phase of the wave by 180 degrees. The order of the fluctuations in frequency is still the same however, so the resultant sound is completely unaltered.

After applying the reverse effect (Effect -> Reverse):

Now of course the sound is completely altered, as the fluctuations in frequency have the inverse order to the original wave.

Attenuation

For this section I'll be editing the below pictured part of the wave form. The sample is the word "equality".

Chosen as there is a very clear difference in the amplitudes of various sections, the middle is far larger than either side.

It can be altered to be as large as the other parts through the Effect menu, namely through Effect -> Volume -> Change Volume. So, selecting that part of the wave and then bringing up the menu:

Some relevant values:

• -6dB reduces the sound by 50.12%
• Increasing it by 3dB increases the sound by 141.25%
• Increading it by 6dB inreases the sound by 199.53%

It's close enough to determine that a 6dB rule applies here, where a sound's volume doubles every 6dB gain and halves every 6dB reduction.

So let's reduce the wave to match the rest of the waveform's level close enough.

There is an audible difference, but it's only slight. This could be useful for making sure a given wave form has a consistent loudness level, which might be necessary when mixing it with other sounds.

So how would I go about bringing this sound to the maximum loudness level possible while avoiding clipping? I could manually adjust the volume over and over until I get it right, or I could just go to Effect -> Volume -> Maximize Volume. This will raise the volume for the selection until the wave with the highest amplitude hits maximum. The result is the loudest this sound can get before information would be lost due to clipping.

The result:

.