Articles and whitepapers

Whitepaper: Holophony - A New Sound Perception System (1/3/2006)

By Alita Howe, Holophonic

ÔHolophonyÕ or Ô3D soundÕ is an innovative sound perception system based on the synthesis of the sound processed along the three stages of the human ear currently being marketed in Europe by Swiss company ÔHolophonic.Õ The potentially revolutionary holophony is far in advance of the stereophonic system currently used in mainstream home entertainment systems, audio equipment and audio products such as CDs and DVDs.

Holophony creates a sound product which, in the final stages of listening, is decoded and interpreted as a genuine primary sound; thus arousing an unmatched sense of reality. In essence, holophony creates a sensation and emotion of reality so authentic, that it appears as though the sound is right next to the listenersÕ ear.

The Development of Holophony

By the 1950Õs, audio techniques had been developed to record and replay sound in stereo using two channels; one for each of our ears. These stereophonic developments facilitated attempts to improve the spatial realism of sound. However, attempts to increase the naturalness and spatiality were only partially successful, as listeners correctly noted that in reality, sound is rarely located as coming from only the left or right hand side. Thus an authenticity of sound through stereophonic means wasnÕt highly noted.

Subsequently, the 1970Õs saw experimentations in ÔquadrophonicÕ sound; allowing projections in four directions; and surround sound. Whilst both providing advancements from the stereophonic research; true authenticity proved elusive. Therefore, starting in the 1980Õs, a research path was developed whose aim was to construct special Ôholophonic transducer microphonesÕ, allowing the reproduction of the spatial characteristics of sound through a traditional stereophonic installation.

Holophonic sound works on the same Ômultiple exposureÕ premise as holograms. Holograms are produced by mixing reflected laser light with a second laser beam hitting an object from another angle. It is this Ôinterference patternÕ that is actually recorded. By recording the interference pattern generated when a soundÕs original recorded signal is combined with an inaudible digital reference signal, a genuinely realistic noise is produced; holophonic sound. Thus, when the brain decodes the holophonic sound, it reproduces the original ambient conditions; creating an unmatched sense of reality.

Sounds are perceived as so authentic additional brain stimulation occurs; inducing other sensory responses such as smell or taste which our brains expect to accompany a sound, creating a truly realistic and emotional effect. Therefore, hearing the holophonic sound of an egg frying may lead people to illicit feelings of hunger and perceptions that they can actually smell the food product. In short; the reality of holophonic sound triggers additional sensory responses. Researchers also intriguingly report that people with audio impairments can receive holophonic sound; because their brains are still stimulated even though there is a hearing disability.

Holophony

During this period, Umberto Maggi; producer, inventor and former member of the Italian band ÔNomadiÕ, began experimenting with holophonic sound and set up a small sound research centre at the Umbi Studios in Modena. There, in 1983, with the help brother Maurizio and a trusted group of sound engineers, Maggi developed the first working ÔHolophoneÕ - a special microphone able to capture 3D sound in all its dimensions by simulating the functions of the human ear and mirroring how the human brain decodes sound.

The resulting Ôholophony Õ system patented by Maggi remained unused and undeveloped in a marketplace with no demand for its revolutionary potential until a meeting between Maggi and businessman Vincenzo Tirella, now Chief Executive of Holophonic, in 2000. Tirella, excited by holophonyÕs potential, became the sole investor in the project, and created ÔHolophonicÕ to market it.

Holophony is an innovative sound perception system based on the synthesis of the sound processed along the three stages of the human ear and works on the same principles of holophonic sound; thus eliciting the same emotional effects and sense of reality. However, twenty years after experiments with holophonic sound began, ÔHolophonicÕ believe they have a marketable version of the technology which can revolutionise the home entertainment market.

Holophony is achieved through balancing an accurate reproduction of materials and dimensional ratios with an electronic supervision via microcomputers that intelligibly superimposes spatial vectors and environmental effects of the sound. This information is then faithfully and accurately reproduced; allowing an unmatched reality of sound to be transmitted; complete with this information.

The ÔHolophone,Õ developed and patented by Maggi, integrates the holophonic function and is therefore far in advance of the stereophonic microphones currently in use. This active unit processes the sound perceived in the environment in which it is placed and superimposes a set of micro items of information that would have otherwise been irredemably lost with traditional systems. The hearing sensation perceived during reproduction is so true-to-life that analysis has proven that it is virtually equal to direct listening of real (ÔdirectÕ) primary sources. Therefore in sum, holophony brings the listener back to the environment where the sound was originally produced, in the exact position in which the sound was recorded.

Evidence

So what evidence exists that holophony genuinely elicits emotional responses and is far superior to current audio transmission and recording systems? Extensive research into holophony was conducted by Tito Pavan and Roberto Caterina at the Department of Psychology, The University of Bologna in 2004. Research into holophony was seen as having a significant scientific relevance in that it facilitated understanding into the impact that quality of sound may have on the meaning we attribute to it.

Thus the research aimed to test the extent to which the holophonic technique can play an important role in inducing emotions through exposing 25 testers to six stimuli; A Tibetan bell, a carillon, a pair of castanets, a hairdryer noise and two human voices which were reproduced in stereophonic, monophonic and holophonic sound and relayed to testers in a random sequence through headphones.

During the course of the research, testers were given a questionnaire to complete, asking them to indicate the direction of sound, whether frontal, left, right, high or low; the degree of movement attributed to the stimulus on a six point scale ranging from 0 (motionless) to 6 (extremely animated); the degree of pleasantness on a seven point scale ranging from -3 (extremely unpleasant) to +3 (extremely pleasant) and the naturalness of the sound on a seven point scale ranging from -3 (extremely unnatural) to +3 (extremely natural).

The hypothesis, unsurprisingly, was that the holophonic stimuli should be perceived by testers as more animated, more pleasant and more natural compared with the same stimuli reproduced in the monophonic or stereophonic mode. Findings from the research broadly confirmed the initial hypothesis and testers clearly perceived the difference between stereophonic, monophonic and holophonic sounds. Stereophonic sounds were perceived as mainly frontal and monophonic sounds were perceived as frontal or originating from the left or right hand side. However, holophonic sounds were perceived as multi-dimensional.

Additionally, holophonic stimuli were perceived as more animated compared to stereophonic and monophonic sounds by testers with an average of 4.280 (out of six) compared to 2.407 for stereophonic and 1.147 for monophonic sound.

Finally, considering that -3 was classed as highly unpleasant and +3 as highly pleasant, findings confirmed that holophonic stimuli are perceived as significantly more pleasant with an average of +1.480 compared to +0.240 and -0.67 for stereophonic and monophonic respectively.

Additionally, results from EEG data taken during the research, coupled with changes in the cardiac and respiratory rhythm of testers suggests that holophonic stimuli can have emotional connotations compared with stereophonic and monophonic stimuli. For example, when listening to the hairdryer stimuli; testers reported feelings of anxiety at the ÔharshnessÕ of sound and changes in their cardiac and respiratory rhythms suggested increased sense of anxiety and panic as listeners reported trying to identify the sound and its proximity.

Conclusively therefore, holophony is perceived by listeners to be a more pleasant and natural listening experience and, based on this initial testing information, it can be argued that the holophony allows real life listening and a more effective transfer of the emotional information intended to be induced.

Applications

Applications of holophony are wide-reaching and span many sectors.

However, the potential for the home entertainment industry is truly exciting. ÔHolophonicÕ are currently working with manufacturers to combine the holophony system with existing home entertainment products such as DVD players, televisions, Hi-Fi and speaker units as well as audio systems, creating a cohesive unit able to fulfil traditional functions but with the added benefit of using holophonic sound.

Consider the potential if holophonic technology was to be combined in a surround sound system; arousing a totality of sound experience whilst listening. This could be implemented across homes, businesses and transport networks as well as being integrated into existing home entertainment applications; allowing the listener to create aural attachments with the sounds they receive, whether this is a televised nature programme or the sensation of a concert taking place within your very own living room through your stereo system.

Holophony can already be used as an original system of sound recording; whereby artists can record using holophonic sound technology at the ÔHolophonicÕ purpose-built studios at Holophonic Village, Bologna. This system of audio recording facilitates the exportation of sound, complete with its original spatial and emotive information, to be reproduced in various locations; therefore, a concert recorded in holophony can be manufactured into a CD and enjoyed by listeners at home as though they were a member of the original audience.

Several successful musical productions have already used holophonic sound. Pink Floyd used holophonic technology during the recording of their ÔFinal CutÕ album and Italian singer Zucchero&Co used holophonic technology when he performed at The Royal Albert Hall in May 2004.

ÔHolophonicÕ has additionally secured worldwide copyright approval from The Vatican City, allowing the successful recording of two DVDs honouring the PopeÕs legacy in holophonic sound.

Whilst the audio sector of the consumer home entertainment market is a saturated one, holophony offers a genuinely innovative, and lucrative option for manufacturers of new home entertainment systems to combine holophonic systems in our everyday home entertainment, theatre equipment and audio systems, since at present, holophonic sound loses most of its spatial particularities and emotional effects when played through regular speakers commonly found in many home entertainment systems. However, the holophonic elements of products already manufactured by Holophonic are easily available to listeners at home; simply by using normal headphones with their existing audio equipment.

Alita Howe is Media Consultant for Holophonic and responsible for UK media enquiries.

http://www.holophonic.ch