Isaiah 6:9 And he said, Go, and tell this people, Hear ye indeed, but understand not; and see ye indeed, but perceive not.

Light is invisible to the human eye. How we perceive objects is the absorption of different color frequencies and the reflection of some color frequencies within the light spectrum which then enter the eye and then are transmitted from the retina to the brain forming images. If light were visible, we would not see anything except the overwhelming issue of light from its source, the sun.

Then we have the ultra-violet and infra-red wave lengths that are just outside the range of the human eyes ability to perceive. Beyond that there are more waves with the same properties as light but with different frequencies. We have instruments to record and measure those so we do know they exist.

Hearing is similar as sight in that frequencies exist that are beyond the human’s range of capability to perceive. Perception only exists in as much as we can naturally hear and see or detect by invention to analyze and record by non-human means, instrumentation. Even then science has to rely upon a fair amount of theory to explain the unexplained. Particles that move faster than the speed of light cannot be seen or felt, yet have been deemed to exist because of causal effect.

Matthew 13:16-17 But blessed are your eyes, for they see: and your ears, for they hear. For verily I say unto you, That many prophets and righteous men have desired to see those things which ye see, and have not seen them; and to hear those things which ye hear, and have not heard them.

How is it that some can see and hear what others cannot? What instrument of perception makes this possible?

Acts 2:38 Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost.

The gift of the Holy Ghost i.e. Holy Spirit is the instrument of perception. He is the eyes that see and the ears that hear, but only to them who believe.