Sometimes, in museums, you can find some very interesting exhibits. Here’s one lying on the floor at the Schwarzenberský palác museum in Prague. I snapped a photo right away, and did a bit of research upon returning home.
This device is a product of Soundlazer, a company that launched on Kickstarter back in 2012 by Richard Haberkern. The device is a speaker that focuses an audio “beam” in a special way. As you can see in the picture, it consists of an array of tiny speakers, each of which is ultrasonic, meaning they emit sound beyond the audio spectrum audible to us. These ultrasonic waves interfere with each other, and as a result, we hear sound within the audible spectrum. Interestingly, you can create this interference at a certain spot in space, so that only there will the input to this device be clearly audible. In practice, this means you hear sound only in specific spots in a room where the device is directed. And if you reflect the sound off the walls… it can well be used to effectively voice hauntings, because the sound seems to come “out of nowhere” 🙂 Or in a museum, it could make a guide that speaks about a sculpture only to a person standing in front of it, while someone only a meter away hears almost nothing. I haven’t tested, but I suspect there must be some high-frequency whistling sound. Does anyone know?
It’s particularly intriguing that such a device can be assembled at home for just a few tens of dollars. It’s really very simple in its minimal form. However, if you think about buying it – I have disappointing news: Soundlazer has long been closed, and a company called Audio Spotlight by Holosonics sells their devices at very high prices, starting at $500. Devices from Ultrasonic-Audio are also quite expensive. VideoTel’s HSS 3000 speakers cost $1275. There are also good solutions from Brown Innovations. But all these are very costly.
Soundlazer was cheap and, interestingly, open source. Although, as we see in the picture, it also used cheap piezoelectric elements to generate sound at frequencies of 40-45 kHz, which probably compromised the sound quality. But it should have been suitable for museums! And interestingly, there is no direct replacement. The cost of a Soundlazer kit ranged from $170 to $200! According to videos, the sound quality was pretty good.
I’ll post a link to the video in the comments.
Hi, I'm Rauf Aliev. 