Fresco is the most common ancient technique for mural decoration. Inevitably, the conservation of frescoes is affected by almost every environmental factor: temperature, humidity, pollutants, biodeterioration agents, and physical shock, for instance, from earthquakes. The vast majority of current diagnoses on frescoes are still performed by experts who rely on their auditory and visual skills. However, to support and help the human senses during the diagnosis, several techniques based on the analysis of acoustic and vibrational signals have been proposed. In this context, this thesis aims to compare different methods proposed in the literature, such as Laser Doppler Vibrometry (LDV), impedance tube, thermographic analysis, and ultrasound analysis, to evaluate the acoustic properties of layers.