If you hear a pure sine wave, then you are hearing coherrent sound. A pure sine wave is completely absent of timbre. From the spectra that I've seen, a flute produces the most timbre absent sound. If you remember the Atari, it has a very timbre free tone generator (not all of its sounds, but some). If you know how to use Matlab, you can write a vector whose components depend sinusoidally on the index, and then use the ?SOUND? (I think that's the command, use the help command to find out for sure) command to make your computer play it. Once you've heard a pure sine wave, the timbre is unmistakeable. The point is, any timbre in the sound is a deviation from the monochromonance. The stringed instruments have a very rich spectrum. The piano and harpsicord are exceptionally timbre rich.Originally posted by Glenn
Can sound waves be created that are coherent in the same way that laser light is coherent?
The concept of coherence of sound waves is a well-established scientific principle and therefore, it is a reality. Coherence refers to the relationship between two waves, where their phase difference remains constant over time. This means that the peaks and troughs of the two waves line up consistently.
The main difference between coherence of sound waves and regular sound waves is the consistency of their phase relationship. In regular sound waves, the phase difference between two waves can vary over time, while in coherent sound waves, the phase difference remains constant. This results in a more organized and predictable pattern of sound waves.
The coherence of sound waves is typically measured using a coherence function, which calculates the correlation between two waves. This function takes into account the amplitude and phase of the waves and produces a value between 0 and 1, with 1 representing perfect coherence.
One example of coherence of sound waves is in noise-cancelling headphones. These headphones use the principle of destructive interference, where two sound waves with opposite phases cancel each other out, to block out external noise and create a more coherent sound for the listener. Another example is in concert halls, where the design and materials of the room are carefully chosen to produce a coherent sound for the audience.
Yes, coherence of sound waves has various practical applications, such as in medical imaging techniques like ultrasound and MRI. In these techniques, the coherence of sound waves is used to create detailed images of the body's internal structures. Coherent sound waves are also utilized in telecommunications and fiber optic communications to transmit information over long distances with minimal loss.