Just as there is an entire spectrum of light out there, so is it with sound. But both our sight and hearing is limited. We seek more information on these from https://en.wikipedia.org/wiki/Electromagnetic_spectrum
The electromagnetic spectrum covers electromagnetic waves with frequencies ranging from below one hertz to above 1025 hertz, corresponding to wavelengths from thousands of kilometers down to a fraction of the size of an atomic nucleus. This frequency range is divided into separate bands, and the electromagnetic waves within each frequency band are called by different names; beginning at the low frequency (long wavelength) end of the spectrum these are: radio waves, microwaves, terahertz waves, infrared, visible light, ultraviolet, X-rays, and gamma rays at the high-frequency (short wavelength) end. The limit for long wavelengths is the size of the universe itself, while it is thought that the short wavelength limit is in the vicinity of the Planck length.Gamma rays, X-rays, and high ultraviolet are classified as ionizing radiation as their photons have enough energy to ionize atoms, causing chemical reactions. Exposure to these rays can be a health hazard, causing radiation sickness, DNA damage and cancer.Radiation of visible light wavelengths and lower are called non-ionizing radiation as they cannot cause these effects.In most of the frequency bands above, a technique called spectroscopy can be used to physically separate waves of different frequencies, producing a spectrum showing the constituent frequencies.
So is it with sound. We refer to https://www.education.vic.gov.au for more clarity on this.
All sounds come from things that vibrate. The faster they vibrate the higher the sound they produce. When things vibrate faster than about 25 vibrations per second we begin to hear a sound of very low pitch. As things vibrate faster the pitch of the sound rises (middle C is 256 vibrations per second, high C is 512.) Even the best human ear can no longer hear sounds when the source of the sound is vibrating faster than about 20,000 vibrations per second. The pitch of a sound is not connected to the volume of the sound.
As the human ear ages it becomes less sensitive and its frequency range reduces, particularly in the upper range above 14,000 vibrations per second.
Scientists call the number of vibrations per second the frequency. Vibrations per second are measured in Hertz.
Sound travels through solids, liquids and gases at different speeds. The sound spreads out from the source in the same way as ripples do on water after a stone is thrown into it. As a result of this spreading out the sound striking our ear at a distance is much less intense than it is close to the source. This is why sounds become quieter as we walk away from them and louder as we approach.
The human ear detects vibrations that strike the ear drum and converts these into nerve signals that travel to the brain. The brain uses previous experiences to interpret these as voices, music, noise, etc. Having two ears helps us to better detect where a sound is coming from.
Many animals can detect sound over a much larger frequency range than the human ear. For example, dolphins, bats and dogs can hear vibrations that we cannot.
Just because we cannot see and hear the extreme ends of light and sound we do not dismiss them. So is it with the many unseen phenomena that takes place in other realms, planes and dimensions. The irony is that when it comes to spiritually we want prove of the emergence of certain phenomena, to belief in it.
We do not need further prove of the existence of a creator or God or a supreme being, if only we take a look within us and begin the questions from here. Right from the outermost sheath, a layer of skin to the microscopic bacteria that resides in this body of ours, is definitely not your creation or mine.
Frank Sherwin in a seminar on "The Miracle of the Human Body" says,
Think of a larger symphony producing the works of Mozart or Beethoven. It all begins with the individual playing his part. This is much like how our body operates with its 11 systems working in concert. Sadly, schools and the media erroneously teach that the human body is the result of “millions of years” of Darwinian evolution. No credit is given to the One who created these amazing systems designed to work as one. Consider our eye construction, the dynamic skeleton, the ability to hear the faintest sound, the brain’s amazing circuitry. The human body – a testament to our Creator’s wonderful intellect!Jordan Gray states,
You have been fed so many lies about your body. Just like there is no wrong tree in nature, there is no wrong body among humans.You are exactly as you need to be. Everything about you is beautiful.Your body works for you tirelessly around the clock, from before you’re born until you die. And yet you never slow down to appreciate it. In fact, you do the opposite. You condemn it. You insult it. You resent it.And it still loves you.
The National Association of the Deaf (US) at its site https://dcmp.org describes the human body as "With its interconnected systems is the most advanced structure in the known universe. It is a marvel of biomechanical engineering."
From http://www.ba-bamail.com, "There is so much going on and everything fits together so well, that it's almost impossible to comprehend. There are miracles going on inside your body every single day."
Who are we then, that are residing in this body, thinking, and performing the various movements and task, and putting those thoughts into action? How is it that we can move this body to perform accordingly to our whims and wishes? When did we begin to reside in this wonderful body of ours? Where do we reside in this body? Where are we in this body this moment? Where are we the moment we doze off ?
But if these are all mind boggling questions and queries that cannot be comprehended and understood, nevertheless to make this life a fruitful and well lived one, the Siddhas have drawn up 4 distinctive paths and simple means, according to one's age and spiritual maturity. For a child he is shown that God dwells in the statue, his abode being the temple. Since children love toys and connect with them seeing them as companions and playing for hours on hand with them, idols easily fascinate them. The child is taught to look at these with reverence and connect with Erai. Growing up they sit together with their parents and learn to conduct rituals both at home and again in temples. Growing older they pick up yoga asanas and pranayama, learning from authentic and trained teachers, to keep their body fit. Finally as they age they will learn to go within and connect with their soul. All the above questions will be answered then from within. An enriched soul carries with it all these experiences and knowledge, while the enlightened spirit makes its way back to the abode of the holy spirit and merges with it, going back home once again to its source.
These four paths can be distinctively classified and categorized as sariyai, kriyai, yogam and gnanam respectively.
External worship first brings one to a state of discipline. With the chanting of mantras and performing rituals, concentration on the task on hand, sets in. With continued faith, a bonus is thrown in. Miracles are shown to bind the devotee with Erai. When simple asanas are done, it tones up the body. All these now help to condition the mind, improving retention and memory, concentration and brings about discipline. With yogasanam, both mind and body is perfected for the divine to dwell within. With the coming of divinity into us, gnanam arises. With gnanam one makes headway in reaching the kingdom of Erai.
Everything has been placed beautifully and has its place and role to play in this divine play of Erai. It is just a matter of us taking it up. In this age of rampant destruction and distractions the Siddhas have given us a very simple path and simplified the means of achieving spiritual progress.
The way of bakti or devotion brings immediate results and progress. Just as one will make quick progress with the guidance and monitoring of a master, so is it possible to make quick progress by taking the hands of the Siddhas. One who has gone the way can easily show us to it. One who has walked the path can lead us to it within a short span of time. One who has worked his way can warn us of its dangers. One who has gone through much in life, can provide solutions to the daily problems that we encounter, provided we asked for it, only after having exhausted our minds thinking of an amicable solution. Take the hand of the Siddhas and you shall see quick progress. The effects of our past actions both in this life and the past, which would otherwise have to be borne squarely on our shoulders, is lightened by Erai and the Siddhas who help us carry it, giving us the additional strength and vigor.