How to Remove Excess Noise Using Audacity

Step 1 (a): To being this operation, first ensure that you are using a functional computer onto which audacity has been installed. To search for audacity, one might refer to three locations. The first and most convenient location would be the desktop. Once signed onto a computer, attempt to locate an icon comprised of a blue set of headphones with a yellow cloud, transfused with a jagged red streak across its middle. Immediately adjacent to this icon (or likely below it) shall be the title “Audacity”( indicating the nature of the program). If it is located on the desktop, double click on the icon (otherwise known as the ‘shortcut’) to launch the program.

Step 1 (b): If the icon is not located on the desktop, then there are yet two locations where the program might yet be found. Programs recently used on a computer are stored on a temporary basis in the start menu. To access this, simply move the cursor to the bottom left of the screen onto which shall be a Microsoft logo and/or the word “start” (the presence of the word start is entirely dependent upon the edition and model of the computer; regardless, the start menu is usually located at the bottom left of the screen). Click on the start menu. Directly above it shall be a series of icons/programs which have recently been used on the computer. If audacity is present, then click on the icon (refer to Step 1 (a) for a more elaborate description of the afore-mentioned logo).

Step 1 (c): If audacity has still not been located, click once again on the start menu located at the bottom left of the screen. Directly above it shall be written “All Programs”. This is essentially a tab which allows the user access to all programs which are currently on the computer. The programs are usually listed in alphabetical order, although occasionally some programs may occur out of this order depending on how recently it has been downloaded. Simply locate the icon (as described in Step 1 (a)) and click on the icon/word to launch the program.

Step 1 (d): If after attempting to locate audacity in the three previously cited locations, and to no avail, one can download the program at http://audacity.sourceforge.net/. Simply follow the onscreen instructions for installation, and then refer to Step 1 (a)/(b) and/or (c).

Step 2: Before the noise removal effect can be implemented, an audio track must first be recorded on which to operate. When audacity has been opened, there is always an available track onto which the recorded information goes. To begin the recording of the voice track, simply move the cursor to the top of the screen onto the taskbar. There shall be a number of functions near the top left, which shall be designated by symbols for convenience. Each symbol is representative of a unique function. Starting from left to right: the two, purple, leftwards pointing triangles adjacent to the line perform the operation “Skip to Start” when clicked. While listening to an audio clip, simply click this button to return to the beginning. The second button is a green rightwards facing triangle. This button plays the audio clip once it has been recorded. The third button is a red circle. Clicking this circle will commence the recording. The fourth symbol consists of two blue, erect, parallel, rectangles, which pause (or otherwise disable) the recording when clicked. The fifth symbol is a yellow square. This square stops the recording, whether it be while in the process of recording, or while listening to the playback version. The sixth and final symbol in this tab (i.e. those functions pertinent to the recording of the clip) is made up of two purple, rightwards pointing triangles affixed to a line. It is a reflection of the first button, and is thus responsible for the inverse of the “Skip to Start” button. Instead, this button is “Skip to End”, and immediately ends the audio track when being listened to in playback mode (i.e. after it has been recorded). Now you have the tools necessary to record a basic audio track. Simply click on the record button, and then the stop button when you are satisfied with the recording which you have made. Of course, to record anything viable, a microphone must be attached to the computer. Simply use any device which is meant to record audio and insert it into the audio jack on your computer (indicated by the image of a microphone).

Step 3: Quite frequently when recording in audacity, background noise, static, and other undesirable noises are recorded along with the intended audio. Luckily, audacity comes equipped with an effect which helps to eliminate this excess noise. After the audio track has been recorded and listened to for reference, highlight a section of the audio track that is comprised purely of undesirable noise (i.e. the very noise which you wish to remove from the track). After this region has been selected, simply select it by moving the cursor to one end of the desired segment, clicking and dragging to the end of the desired segment. After this has been highlighted, the section shall be a darker shade of blue than the remainder of the audio clip. This is how you are aware that is has indeed been selected.

Step 4: After the portion of excess noise has been highlighted, move the cursor up to the very top. First, move the cursor to the very top left, over the audacity logo and title Directly below this shall be a tab with various functions on it. Immediately beneath shall be the word “File”. File is the first option in this tab. Move the cursor to the sixth option in this tab, “Effect”. Click on “Effect”, after which a box shall appear with a myriad of options. These effects are dynamic and far-encompassing. However, for the purposes of this tutorial, only the Noise Removal option shall be required.

Step 5: Now that the effects tab is opened, there shall be a number of available options. Below “Effect” is the function “Repeat Last Effect Ctrl+R”, and beneath that in turn is a series of other options which are listed in alphabetical order, starting with “amplify”. Go to the fourteenth operation in this list, the title of which is “Noise Removal”. Click on “Noise Removal”. *Depending on the edition of Audacity, Noise Removal may or may not be the fourteenth option from Amplify. If not, then simply locate Noise Removal wherever it so happens to be under the Effect tab*

Step 6: After clicking “Noise Removal”, a new box shall appear, with “Step One” and “Step Two”. The instructions provided at this point are self-explanatory, but shall nevertheless be discussed in this tutorial. Audacity can only filter out noise when it is given proper direction by the user. To instruct audacity on what noise must be removed, a segment of ‘just noise’ is selected, so as to familiarize the program with what is undesirable. Now that the noise has already been selected, simply click on the button that says “Get Noise Profile”. What this essentially means is that audacity shall process the audio that has been selected and classify it as undesirable. Now the program is capable of eliminating only this variety of noise.

Step 7: After clicking “Get Noise Profile”, the box shall close itself, but the noise profile has now been successfully identified. At this point, you may highlight the section(s) of the audio clip which you wish to have the noise removed from. It may range from a small portion to the entire audio track. Simply click and drag to highlight (for more detailed instructions on how to highlight, refer to Step 3)

Step 8: Once more, locate the “Effect” tab and click on it (for more detailed information on how to locate the effect tab, refer to Step 4)

Step 9: After the “Effect” tab has been opened, simply locate and click on the “Noise Removal” option (as outlined in Step 5).

Step 10: Now that “Step 1” of the noise removal function has been completed, disregard it and proceed to “Step 2”. At this point, the noise profile has already been defined and selected. Ergo, audacity is aware of what information should be removed and which information should be preserved. There shall be a long horizontal line, the left end of which shall read “Less”, and the right end of which shall read “More”. Near the middle shall be located a downward-pointing pentagonal bar which may be dragged left or right. The degree to which you move this bar is entirely dependent upon how much noise must be removed from the highlighted section. Be mindful that removing too great an amount of noise may result in the distortion of the original track, whereas removing too little may allow the excess and undesirable noise to obscure the segments of the audio which are important. To avoid an unnecessary and tedious mutilation of the original audio track, there are two tabs located at the very bottom of the box. The one to the left that says “Preview” provides short sampling of the highlighted section, as it would sound subsequent to the application of the effect. This allows the user to experiment with the program, and arrive at a suitable degree of noise removal via trial and error. When you have adjusted the noise removal to your satisfaction, simply click “Remove Noise”. At this point the box has been removed, as well as the noise. The track shall now sound as it did in the preview (or rather the highlighted sections of the track). Congratulations, you have now successfully removed excess noise from an audio track using Audacity.