Scientists from the École Polytechnique fédérale de Lausanne or EPFL have developed a new invention that is able to split any kind of sound into several frequencies. This type of acoustic prism can find its best use in sound detection. Several centuries ago the famous scientist Isaac Newton has proved and showed how a prism can split the regular white light into the specter of rainbow colors. Every color was in accordance with different frequency. This type of optical prism is reliant on the refraction which splits the light into several frequencies. So now finally the scientists have found a prism for the sound as well.
This new invention is an acoustic prism that can split the sound in different frequencies just by using physical properties. Unlike the optimal prism, this acoustic prism is completely man-made, without help from machines or robots. So how exactly does it work? Well, sound decomposing into constituent frequencies is reliant on the proper interaction between the structure of the acoustic prism and the sound wave. The prism is modifying each separate frequency from the sound wave, without the need for electronic components.
How does the prism look like? The acoustic prism is an aluminum-based tube with the rectangular shape. It has ten aligned holes on the one side. Each and every hole ends with a cavity within the rectangular tube, and there is also a membrane between two cavities. When sound enters into the tube from one end, the components with high frequencies exit out of the tube from the holes that are near the source. The low frequencies, on the other end, exit through those holes that are away at the other tube end. Similarly like in the optimal prism, sounds get dispersed and angle of dispersion depends on the frequency of the sound wave. The key for the prism to function are the membranes. This is because they are vibrating and sending the sound to the cavities with a slight delay depending on the sound frequency. Delayed sound goes through the cavities and towards outside, which disperses the sound.
To take this invention one to next level, the scientists have found out that they can use the prism as an antenna in order to locate the precise direction of the sound in the distance, just by measuring the sound frequency. Due to the fact that every angle of dispersion corresponds with particular sound frequency, it would be enough just to measure the main component of the frequency from the incoming sound in order to determine the precise location from where it comes. This can be done without even moving the acoustic prism.
The key behind the acoustic prism is the design of the membranes, ducts and cavities, which can be miniaturized or fabricated easily. That could lead towards cost-effective detection of the sound without using moving antennas or expensive microphone arrays. This new invention still needs modifications and improvements, but the future looks bright. It can completely revolutionize the way we hear sounds and it can give the scientists a solid base to work on.