Indeed. That's absolutely correct.

Mantras are repetitive sounds - used to penetrate the depths of the unconscious mind and adjust the vibration of all aspects of your being.

Mantras are vibrated through chanting aloud, mental practice, or by listening to them. Though it can be even practiced silently but that's the later part of Mantra Meditation. As the primary focus of it is to chant aloud and listening to the sound (not the Mantra in particularly).

In yoga, mantras are typically chanted in Sanskrit. The Sanskrit word mantra is derived from the root of man which means “to think,” and tra from trai which means “to protect or to free from bondage” or “to free from the mind.”

Thanks & have a Blessed Day ahead... :)