Srila Prabhupada said:
The prayers of Narottama dasa Thakura. This sound is above the material platform. It is directly from the spiritual platform. And there is no need of understanding the language. It is just like a thunderburst. Everyone can hear the sound of thunder–there is no misunderstanding. Similarly, these songs are above the material platform, and they crack like thunder within your heart.
From Srila Prabhupada-lilamrta