Auscultation is the procedure by which the condition of an infrastructure is evaluated, when it is in use or in good condition, and without interfering too much with the normal users of the infrastructure.[1]​ It is a common procedure in large engineering works, such as dams, bridges, railways and in aviation.

Monitoring of railway lines is carried out periodically on all lines, more frequently on high-speed lines, or when a problem is detected. Monitoring is carried out through monitoring trains or monitoring cars coupled to conventional trains, which are capable of measuring the parameters of the infrastructure while they circulate through it.

The values ​​that a monitoring car can measure are several and can vary from one to another: vertical acceleration, horizontal acceleration, slope, tension of the catenary "Catenary (railway)"), height of the catenary "Catenary (railway)"), operation of the beacons, etc. The values ​​are measured to mark those that go beyond what is established as normal parameters. At those points where the track is out of range, the infrastructure is repaired to return it to its original state and it is monitored again to see if the solution adopted is correct.[2]​.

Auscultation in prey is continuous throughout the life of the prey. Different measuring instruments are placed along it that work all the time, and that those responsible for the dam consult periodically. These devices measure different values, such as the opening of the joints, the inclination or the presence of radon gas. The technicians decide at all times to what extent the dam can be filled according to the data they obtain from the auscultation.[3]​.

By auscultating slopes, the following variables are controlled:

Through auscultations and surveys of interurban roads, highways, among others; You can get to know different parameters such as:

Inter alia.