We have selected for you the most notable materials from our Hi-Fi World: from acoustic levitation to money transfers using sound and almost one hundred percent sound insulation.
If these topics are of interest to you, we invite you to cat.
A photo Sara rolling / Unsplash
- Musical roads – what is it and why they are not in Russia. We talk about how roads sound in different countries. The principle of operation is as follows – on the road surface grooves of a certain depth are made, they are located at different distances from each other. And if you drive through them at the right speed, you can hear the melody. The closest analogy from the world of audio is playing vinyl. Interestingly, in Denmark such coatings were tested in the early 90s, other well-known experiments were in South Korea and California.
- “We Heard You”: Audio Technologies in Retail. We all heard the phrase: “To improve the quality of service, all conversations are recorded.” Now it’s not just about call centers. So, Walmart installed near the cash desks audio systems that record the communication of employees with customers. Then these records are analyzed and evaluated. Even in retail, there were some voice assistants: orders for coffee through Alexa, purchase of products through Google Assistant. In general, “the future is here.”
- “It was possible”: unusual, but effective ways to use “audio” technologies. Did you know that aerophobia can be dealt with with odor headphones? An ordinary “jack” can be turned into a thermometer, an oscilloscope and an entire portable weather station. And with the help of sound waves of a certain frequency and amplitude, you can lift small objects into the air. In addition to gadgets and research, we discuss the use of audio technologies for health – we talk about the “lung flute”, which helps to get rid of some sores with the help of low-frequency waves.
- What is 8D audio: discussing a new trend. We must say right away that this is not a new technology, but a different way of delivering material. The technology is based on the structure of our ear and the so-called transfer function of the head, it is also HRTF. But the reaction to such music (there are examples in the article) is ambiguous – after all, HRTF is individual for each person.
- How to read the sound of a packet from under the chips or what is a “visual microphone”. This article is about technologies that allow you to record sound from a distance. A bit about laser microphones, NASA technology and the horn antenna. And for dessert – a visual microphone. It allows you to restore sound based on the footage. The creators of the technology say that while the quality of such a sound leaves much to be desired, but they are working on it.
- How digital money “sounds”. In this article, we study the payment system introduced by Google in India. The technology of data transmission using sound is not new in itself – IBM developed something similar back in the 40s of the last century. Nevertheless, this method is on a par with Bluetooth, NFC and other contactless communication methods. In the article, we understand how it all works, how data security is ensured, what are the advantages (spoiler: so far exclusively related to Indian characteristics) and disadvantages.
- Release of “HD-plate”: a new technology will be released next year. We analyze what “improved vinyl” is. Stages of production – from converting the audio file into a “topographic three-dimensional map” of the future record to pressing. We are also discussing other approaches that are beginning to be applied due to the growing demand for vinyl.
- Directional sound: technology that can replace headphones – how it works. About the dream of everyone who hates teens with speakers. And how to make a sound that in a room with several people only one of them will hear. This problem began to be solved back in the 80s, but at a rather primitive level. It was assumed that the listener stands in one place. And in our days in Israel have developed an acoustic system with sensors that track the position of the head of the listener. So far, the technology has drawbacks, but they are being eliminated, and there are more applications – from museums with audio guides to shelves with audio equipment in stores. Many hope that soon they will not have to listen to the next Feduk on the bus with a crowd of teenagers, but each has his own way of listening.
A photo Blaz erzetic / Unsplash
- Audiotechnology: how pieces of plastic are moved using ultrasound and why is it needed. We talk about the development of the “acoustic tweezers” technology, which allows you to lift small objects into the air using ultrasound. If earlier it was possible to raise only one object in this way, then this approach allows you to work with several at once and even control their movement. There are many fields of application – from medicine to the sphere of entertainment and the creation of three-dimensional holograms. The article also contains information on similar developments: from acoustic printing to the creation of ultrasonic fields of various shapes.
- A sound insulation method has been developed that dampens 94% of noise – we tell how it works. The ring printed on a 3D printer works more efficiently than the most advanced soundproofing systems. The principle of operation is based on the Fano resonance – due to the special shape of the ring, the energy of two waves during interference is distributed asymmetrically. At one point, the acoustic pressure reaches maximum values, and at another point it drops to almost zero. The article has a video with a prototype and a discussion of technology.
Even in our blog on Habré we talk about forgotten audio formats:
- Beginning of an era of compact audio or “first shift” for bobbin
- The era of compact audio: how tapes came into cars