Beside neurosurgical applications, one of the most common application field is the monitoring of the vocal cord nerves during thyroid surgery.

Surgical manipulations at motor nerves lead to mechanical nerve irritations which result (through action potentials) in contractions of the innerved muscles. These contractions can be measured with needle or surface electrodes (EMG) and represented acoustically over a loudspeaker or optically on a display. The surgeon "hears" or sees any muscle activity caused by surgical manipulations.

The nerve can be stimulated simultaneously with a special stimulation probe leading to muscle contractions if the nerve is still intact.