 In this screencast, we are going to discuss the three main steps of editing an audio file. First of all, we will check and adjust the sampling rate and the resolution, then we will continue with the removal of background noise and the deletion of unnecessary sections. Finally, we will normalize our audio file. Now, let us assume we are working with the welcome message for our language index. First, we want to check and adjust the sampling rate and the resolution. In order to do that, we go to the menu, to edit and then to preferences. A new pop-up window will open and we have to select the quality. We have to set the default sample rate to 22,050 Hz and the default sample format to 16-bit. As you can see here, then we have to confirm with the OK button. Any audio file you import afterwards should be displayed with these settings. Both the frequency of the imported audio track and the project frequency, which is displayed in the lower left corner of the audio track, should be set to 22,050 Hz. If this is not the case, you can change the frequency and the sampling format manually. In the audio track, click on the little black arrow and go to set sample format. There you can select 16-bit as well. If we go to the little black arrow again and to set rate, we can also select the 22,050 Hz again. Another important point is to have the file in mono and not in stereo sound. You can easily separate stereo files and convert them to mono files. Select the file by clicking in the cutting window and then go to tracks in the menu and select stereo track to mono. Now we want to remove background noise or other unnecessary sections. In order to find these, we have to listen to our sound file first. Then we can select the area we want to delete and use the cut button or the delete key on our keyboard. It is sometimes very important to have a short pause between two sentences like in our welcome message for instance. So we will generate a silence. If we go to the menu bar, we can select silence and we can also select the duration of the silence. As the last step, we will normalize the file to a level volume. Recordings that are too loud or too quiet need to be normalized to a level volume. In the menu, go to effect and normalize. In the dialog, you should not choose the highest possible value, but a value that is a little lower for example between minus 1 and minus 2 decibel and confirm with the OK button. Before you export your completed audio track as an mp3 file, you should save the project. For this, you need the lame plugin to be installed, which you can download from the Audacity homepage. The completed audio file should be an mp3 with the highest possible quality.