According to the World Health Organization (WHO), the harm caused by noise to human health ranks second only to air pollution in urban areas. In several of Vietnam’s major cities, noise levels frequently exceed the allowable limit and tend to worsen. In order to improve urban management, particularly noise pollution, proper noise level assessment equipment is required. Furthermore, the col- lection and processing of audio data for automatic and intelligent control applications is currently a promising research fi eld. For the reasons stated above, we have decided to carry out the graduation thesis on the topic "Design and implementation of a portable audio signal spectrum analyzer". The objective of the project is to study and implement a compact, aff ordable device for measuring and displaying sound intensity levels. The design employs the ESP32 central control board to communicate with the MEMS ICS43434 Microphone via the I2S (Inter-IC Sound) standard, allowing for high- quality and effi cient sound recording directly from the environment. In real time, the audio data is analyzed using the Fast Fourier Trans- form (FFT) algorithm. The magnitude of each frequency component of the recorded sound can be directly observed on the LCD screen or magnifi ed for display on an LED panel (if necessary). Experi- ments using the designed equipment to analyze a variety of sound sources yielded very promising preliminary results.