You will need
  • Microphone, computer with sound card, software audio editing program.
Check the settings of the sound card. In order to do this, open the control panel of your audio device (usually located in the lower right corner of the screen, near the clock).
In the opened window find volume controls, which are responsible for the connector that you put a microphone (depending on the model of the sound card and may be referred to as "Mic", "Front Pink in", "Rear pink in" or similar). Expose these controls for maximum volume, make sure they are turned off (the channel is usually a red cross on a schematic image of a speaker to turn up the volume, click on this symbol). Make sure that the "Recording" tab selected your sound card, and controller of the recording level there is also exhibited to the maximum.
Find it in the settings select "microphone boost". For example, in one of the most popular models of embedded sound cards it appears when you press a small button located under the volume control for your recording channel. After clicking it, a window will appear in which you need to put a check in the "microphone boost".
To increase the volume level after recording. Modern audio editors have a convenient means to do this. Usually functions that work with the amplitude of the sound are located in the "Effects," "Amplitude," "Normalization". Or similar, depending on the editor.
For example, select the function "Normalization". Specify the level at which you want to normalize the audio track (e.g., 100%) and click OK. Weak recorded signal will become louder.