nabhasah sabda-tanmatrat

 kala-gatya vikurvatah

sparso ’bhavat tato vayus

 tvak sparsasya ca sangrahah

 

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 

 

From ethereal existence, which evolves from sound, the next transformation takes place under the impulse of time, and thus the subtle element touch and thence the air and sense of touch become prominent.

 

Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 

 

In the course of time, when the subtle forms are transformed into gross forms, they become the objects of touch. The objects of touch and the tactile sense also develop after this evolution in time. Sound is the first sense object to exhibit material existence, and from the perception of sound, touch perception evolves, and from touch perception, the perception of sight. That is the way of the gradual evolution of our perceptive objects.