Thomas Edison's first wax cylinder recordings in 1877 contained a lot of hiss, crackle and noise. You could say that all of the advancements that have been made in sound recording since that time have been focused on producing clearer, cleaner and more authentic sounding recordings. Improvements in recording technology were made through the early decades of the 20th century. By the late 1950s, techniques had been developed to both record and re-play music, sound effects and recordings of the human voice more faithfully and in stereo. Stereo sound is played with two channels, essentially one channel for each ear.
Even with the high fidelity stereo recordings, audio engineers and audio enthusiasts noticed that sound effects and voice recordings never seemed to fully reproduce life-like sounds. Sound has a physical presence as well as an audible presence. A sound carries a message with it about its location in time and space. That message resonates within the listener. Sound effects are not heard only by your ears, they are actually felt by the whole person.
High quality sound recordings of sound effects are often made using "binaural" recording techniques. A two-track digital recording device is connected to two microphones that are mounted on a dummy's head. The head has ears, sinus cavities and mimics other features of the human head. This helps the microphones pick up and record sound more like the way the human ear hears it.
In the 1970s the new audio rage was quadraphonic sound. Quadraphonic sound was recorded and then played back in four directions. Surround sound was born when the four channels of quadraphonic sound were joined by a fifth channel. 5 channel surround sound uses 5 recording and playback positions: left, right, front, back and center. 5.1 surround sound adds an additional subwoofer channel of low frequency (or LFE) sounds to add more realism and allow the listener to really feel the sounds and sound effects. The addition of the subwoofer to create a more realistic audio experience is the next step in the path toward the development of holophonic recording - a step beyond surround sound.
Holophonic sound recording was developed by Hugo Zuccarelli in the 1980s. How does it go further than surround sound?
Holograms use multiple exposures of an image to create holograms. Holophonic recording uses multiple exposures of a sound recording to create a holophonic sound. How do you produce a Holophonic sound recording? You add layers to the recording by including the interference pattern that is generated when the original recorded signal is combined with an inaudible digital reference signal.
It is hard to explain, but the recorded sound produced in this way is so realistic that some people claim they can smell sulfur when they listen to a holophonic recording of someone striking a match. The Holophonic Sound waves appear to stimulate the brain to reproduce very realistic and three dimensional sounds within us. That includes stimulating other responses within us like sensations and smells that usually accompany a sound. Even more interesting is the fact that researchers report that some hearing impaired people can "hear" Holophonic Sound - again because it stimulates their brains even though their audio receiver mechanisms are not working properly.
Holophonic sound recording is being used by a growing number of professional recordists and sound designers for broadcast, film and multimedia applications. Even at this point, more than 20 years after its invention, the best way to experience this breakthrough recording style is through specially designed speakers or with headphones; it is not ready for home theater demonstrations.