Zenton has extensive experience and knowledge of directed sound and how directed sound should be used in different environments with different conditions.
If you turn on a light bulb in a dark room, the whole room will be illuminated, but if you turn on
with a flashlight, you only illuminate the part you point the beam at. The same is now possible
to achieve with directional sound.
You can also “project” sound. This involves bouncing the sound off a hard surface which in turn
causes the sound to originate from the surface from which it bounced.
So you can create a virtual speaker from any hard surface.
Directed sound can be used in a number of areas, for example:
– Shop environments
– Shopping centers
– Digital signage
– Trade fairs
– Sound masking
The only limit is your own imagination.
How does directional sound work?
The directivity of a wave-producing source depends on the size of the source compared to the wavelength it produces. Audible sound has wavelengths ranging from a few centimeters to a few meters, and since these wavelengths are comparable to a pair of normal-sized speakers, the sound spreads. Only by making a sound source much larger than the wavelengths it produces can the sound be directed in a narrow beam.
It is hardly practical to use speakers that are tens of meters in size. To get a narrow sound beam out of a small acoustic source, you have to generate ultrasound instead. The wavelength of ultrasound is only a few millimeters, which is much smaller than the size of the source, so the sound travels in an extremely narrow beam. The ultrasound emitted contains frequencies of about 50,000Hz. In comparison, the human ear can perceive between about 20-20,000Hz.
When high-frequency sound travels in a narrow beam through the air, it is distorted in a predictable way. This distortion emphasizes parts of the audible bandwidth that can be precisely controlled. By generating the right ultrasonic signal, we can create virtually any sound in the air. If you break the sound beam, the sound occurs where you are standing and is perceived as coming from inside your head. The sound is only audible to those in the direct path of the sound beam.
Sound can also be reflected against a hard surface to place sound in a location where you would not normally be able or willing to use normal sound sources. This is called ‘projected sound’. Projected sound is perceived as coming from the part from which the sound was reflected. The sound beam is about 0.5 m in diameter and spreads only about 5-10 degrees from the sound source.
See which products we can offer under products – directional audio or contact us for more information on which product is best for you.