Auditory perception is a complex phenomenon, in which the physical characteristics of received sound, the physiological of the ear and the neural activity of the brain interact in a subtle way. On these pages we wish to show how auditory perception should not be considered as a faithful image of received sound but rather a complex (and not very faithful) processing of it.
We should distinguish between effects and illusions intending that effects are “non-faithful” perceptions due to physiological characteristics of the receiving apparatus, while illusions – similarly to the more famous optical illusions – are a product of the brain’s direct action that does not limit itself to just registering sounds it receives but also interprets them.
I recently read an article where I found interesting examples of sound illusions. Since Noisyvision is born from the idea that we see and hear with their eyes and ears but with the mind and heart, illusions are a way to understand that also what we hear is filtered by rules basedon the experiences, memory, education, taste, knowledge. In the video below the sound seems to go on forever go down in pitch. You can also “build” on the contrary, in a tone that seems to rise indefinitely.
The illusion is obtained with the notes that belong to a set of scales descending (or ascending), the individual notes of the various scales are played simultaneously. Thus it seems that the scale fall or rise constantly in tone even if the end of the illusion you find yourself at the beginnign
This video also explains how the ear can be fooled by what the brain wants to hear
The video below is not a real illusion, but it shows how audio techniques can create a surprising imaginary thanks to the extraordinary potential of our brain to calculate the distances based on the perception of sound (I highly recommend keeping the eyes closed, as suggested by the video itself)