Q & A
What is Lite2Sound?
It’s a portable audio device that lets you hear sounds from light. Plug in headphones and point it toward light sources. Many lights are varying in brightness rapidly but your eyes can’t detect that information. Lite2Sound accurately senses fluctuations in light intensity and amplifies those waveforms into audible sound.
What is Lite2Sound not?
It’s not a synthesizer. The sounds it makes are not generated internally. It can’t generate sound from everything you point it at.
Is it a kind of microphone?
No. Lite2Sound is not a microphone because it doesn’t sense acoustic vibrations (variations in air pressure). The audio that you hear from Lite2Sound might be very different than what you hear with your ears. Nevertheless, the technique of positioning a Lite2Sound device to capture a subject is sort of like microphone technique. If you have experience with microphones you already know that sometimes small changes in the position and angle can make big a difference in the sound quality.
When and where does it work best?
Lite2Sound is best at night or in low light indoor spaces. The more daylight illumination in a scene, the quieter its output will be. Thats because diffuse daylight from the sun is not modulated, therefore it is silent. So if you’re just starting out, wait until night.
So you can actually hear light?
Not exactly. What you hear is fluctuations in light intensity that have frequencies in the audible band, between 20 Hz – 20 kHz. Any light source that lacks modulation will add silence to the Lite2Sound output. Also, lights that are modulated more rapidly than 20,000 times per second don’t make sound either because their frequency is outside the range of hearing.
Where does modulated light come from?
Many technologies emit modulated light. Common and legacy type light bulbs are often modulated at harmonics of your AC mains grid frequency. Newer lamps that are dimmable or use high-efficiency technology are modulated at various frequencies. Automotive lighting often emits modulated light at multiple frequencies simultaneously.
Light can also be modulated naturally by passing through turbulent air.
Light can also be modulated deliberately for creative purposes by making it reflect off of a vibrating or changing surface. When light bounces off of the surface of moving water, audio information is carried with it. Or, light can be modulated by occlusion if it passes through a moving barrier such as a spinning fan or vibrating insect wings. Spinning discs called tonewheels are marked with patterns of dots,stripes or lines to modulate light for sound synthesis.
Can you hear colors with it?
No, Lite2Sound does not distinguish colors. There’s no fundamental difference between the sounds made by different colors of modulated light. However, it is also sensitive to infrared light. So its possible to hear sounds from completely dark scenes when infrared sources are present.
What does Lite2Sound connect to?
Lite2Sound’s output is analog audio. You can connect any headphones that have a standard 3.5mm plug. You can also plug in an Aux cable between Lite2Sound and any audio device that has an analog Aux In jack. That means you can connect it to portable speakers, bookshelf audio units or car audio systems for listening. For recording, you can use an Aux cable to connect it to the Mic/Line input of many portable recording devices. Or with simple audio adapters it can be connected to the analog line inputs of any pro audio system.
I noticed there are different versions of Lite2Sound. Do they sound different?
Not really. This isn’t like the world of synthesizers where every model can make unique sounds. It’s more like cameras or microphones. Lite2Sound is type of sensor so there are differences in the sound quality between versions. As the Lite2Sound versions have progressed, their performance has been refined by reducing the circuit’s self-noise, increasing the dynamic range and improving rejection of interference. This makes a difference in how far a distance you can be from a signal’s source without its sound quality being compromised by circuit noise or unintentional reception of electromagnetic field (EMF) sounds.
Model | Audio Channels | Sensor Size | Phones Output | Record Output | Tripod Mount | Internal Speaker | Aperture Size | Field of View (deg) | DC In | EMI Shield |
| Lite2Sound PX / PX2 | 1 (mono) | 1 mm2 | Yes | Yes (PX2) | – | – | 5 mm | 20 | – | – |
| Lite2Sound QB Stereo | 2 (stereo) | 1 mm2 | Yes | Yes | Yes | Yes | 5 mm | 20 x 30 | Yes | Yes |
| Lite2Sound EP | 1 (mono) | 8 mm2 | Yes | – | Yes | – | 22 mm | 10 | – | Yes |
| Lite2Sound HD Stereo 40mm | 2 (stereo) | 96 mm2 | Yes | Yes | Yes | – | 40 mm | 20 x 40 | – | Yes |
| Lite2Sound HD Stereo 62mm | 2 (stereo) | 96mm2 | Yes | Yes | Yes | – | 62 mm | 24 x 14 | – | Yes |
With Lite2Sound PX and PX2, the basic versions, you will generally get cleanest audio when it is close to a light source, a few inches or feet away. With our later Lite2Sound devices you can capture quality audio from much farther away. This allows a greater area of view for blending sounds together. The later versions also offer advantageous sound quality for up close work in the studio.
Other differences between Lite2Sound versions are a matter of stereo vs. monophonic output, and convenience features like power supply options, internal speaker, number of audio outputs,and camera tripod mount.
What kind of sensor does it have?
Lite2Sound devices use silicon PIN photodiodes. These receive wavelengths between 400nm and 700 nm, which includes all colors of visible light from deep blue to deep red. These sensors also pick up infrared light in the range 700 nm to 1100 nm. This is the domain of IR data links, night vision camera lights and other hidden technologies. However, it does not sense ultraviolet UV light.
What is its image resolution?
This is a trick question, because its is not an imaging device! The monophonic versions of Lite2Sound have resolution of 1 pixel, and the stereophonic versions could be considered 2 pixels. In contrast to cameras and video imaging devices, the bandwidth of the signal aka the effective shutter speed of Lite2Sound is much higher. A video sensor would need to deliver a frame rate of more than 20,000 FPS in low light scenes to match the bandwidth of Lite2Sound’s sensor electronics. Its unlikely that any consumer video device in past or near future could duplicate what Lite2Sound does.