This bachelor's thesis deals with the simulation of electronic circuits with a focus on the processing of audio signals. At the beginning of the work a detailed procedure and instructions for work in the selected simulation program LTspice are described. The program is free to download, so anyone can try the simulations. The import, processing and export of audio files are also described. The sound of an electric guitar, a spoken word in a male voice, rock and synth recording are then discussed in more details. The last part is devoted to detailed examples of the functions of the tested circuits. The circuits tested are high-pass filter, diode limiter and effect pedal Fuzz Face which is compared with real constructed unit. The verification ...