What is 3D sound?

What is 3D sound?


3D Sound:


The 3D sound effect is to use a speaker to imitate a seemingly existing but fictional sound. For example, a plane on the top of the speaker mimics the plane flying from left to right. When you close your eyes, you will feel that there is a plane flying overhead from left to right. This is the 3D sound effect. About a few years ago, Diˉamond Multimedia boldly launched a new PCI-specific Monster Sound sound card. They used Microsoft's DirectSound API to solve the problem of game sound compatibility, and introduced the ISA card to be compatible with the old DOS games, which was one of the products that many audio cards dare to be incompatible with the Sound Blaster specifications. The reason why this card survives is that this sound card has its own API function library, also called A3D system. Its greatest strength is the 3D stereo sound.
Chinese name 3D stereo sound Foreign language name 3 d sound Interpretation Fictional sounds imitated with speakers Application range Includes graphics, sound effects, etc.
table of Contents

1 Technical introduction

▪ Sound effect positioning
▪ Echo effect
▪ Application range

2 A3D technology

▪ Technical brief
▪ Include content

3 Similar techniques

4 Technical Summary

Technical brief editor

 Sound effect localization

 3D sound positioning A3D

 The biggest difference between A3D technology and traditional practices is that it can use a set of speakers or headphones to deliver realistic stereo effects, locating sound sources that surround different locations around the user. This ability to track sound sources is called positioning sound, which uses the capabilities of the HRTF at the time to achieve this magical effect.
The full name of the so-called HRTF is Head-Related Transfer Function, which is how the human ear monitors and distinguishes the source of sound in a three-dimensional space. To put it simply, the sound waves are transmitted to your ears in a few millionths of a second, and our brains can discern those subtle differences, use these differences to distinguish the shape of the sound waves, and then convert The source of the position of the sound in space.
In most current 3D sound effects, the HRTF conversion algorithm is used to convert the sound effects in the game, misleading your brain to hear the sound coming from different places. A game that supports sound source positioning combines sound with the source of the game's objects, characters, or other sounds. When these sounds change position with you in the game, the sound card will adjust the sound signal transmission based on the relative position.
Echo effect
In addition to recreating the sound of the game, developers of 3D sounds try to use the effects of echo and other ambient sounds to make the sound of the game more stereo. In fact, the so-called reverb effect is basically sound. Reflection. 3D is more convincing
Many people may think that this is the boring requirement of music lovers. In fact, the sound effects in computer equipment are not only brought to the enjoyment of music lovers but also brought to game lovers. A certain shock.
If you are playing a CS or QUAKE 3 shooting game, plus a pretty good 3D sound device, it feels like being in it, the gunshots when shooting, the screams when you shoot, and A slight footstep can improve the quality of the game.
If you only use a PC speaker to watch the DVD, you can imagine that the effect will quickly make people crazy. If you have a set of powerful 3D sound effects equipment when watching DVD, the whole effect There will be a brand new change. Especially when watching an imposing film, high-quality sound can bring you into it.
The above is a brief introduction to 3D sound effects. Every one can imagine how beautiful they can be if they are in a high-quality sound place.
The current DirectSound3D is a fairly solid API, and the open architecture designed by it will make the game's 3D sound more convincing and powerful. It is estimated that in the future development, 3D sound effects will also develop like graphics cards.
Application range
The scope of 3D is actually very broad, including not only graphics but also sound effects. Friends who love 3D games may only care about the sleek and realistic graphics visual effects. In fact, to truly bring the feeling of presence, 3D sound effects are also essential. With Aureal and Creative launching their new sound technologies A3D and EAX, "3D Sound" has become more popular. Let's take a look at some of the most popular 3D sound technologies.
A3D technical editor
Technical brief
A3D is a brand new interactive 3D positioning sound technology developed by Aureal Semiconductor. Software (especially games) using this technology can output corresponding sound effects according to interactive scenes and sound source changes in the software. Extremely realistic 3D positioning sound for a true listening experience, all with just a pair of regular speakers or headphones.
Include content
A3D technology consists of two parts: A3D Surround and A3D Interactive. Let me explain it separately.

1. A3D Surround: This technology is "surround", which allows the sound source to be accurately positioned in the three-dimensional space surrounding the listener using only two ordinary speakers or a pair of headphones. A3D Surround combines surround sound decoding technology such as Dolby's ProLogic and AC-3. The surround sound decoder creates a sound field surrounded by 5 sets of audio streams through two speakers, which means you can experience Dolby with two speakers. Five speakers surround the effect, this technology was awarded "Virtual Dolby" certification by Dolby Laboratories.

2. A3D Interactive: This technology is "interactive", it can produce interactive 3D sound effects for interactive games and some interactive software applications, creating a very realistic and interactive 3D hearing environment. We know that the sounds heard, in reality, are not static, but that we are responding to changes in our actions, our environment, and the relative changes in the relative positions of sound sources and human ears. of interaction". Surround sound technology like Dolby Surround can achieve excellent surround sound with the help of multi-speaker systems, but these technologies are non-interactive and can't be used for today's interactive games and interactive software. To achieve these truly interactive listening experiences in a software application, these interactive sound effects must be simulated while the sound is being played back, which requires the audio processing system to calculate the audio changes and play them back in real time. And A3D Interactive can be said to be the pioneer of this technology on the PC. A set of A3D-enabled applications combined with the A3D sound processing system can produce extremely realistic 3D interactive sound effects.
The key technology of A3D is based on a theory called HRTF (Head-Related Transfer Function) (I will explain it to you later). The sound generated by the powerful HRTF filter in the Vortex chip can make the brain accurately locate the sound. The 3D orientation of the source. For the first time in A3D, Wavetracing algorithms developed by NASA have used reflections, reflections, and obstructions of obstacles. Accurately reproduce real-world sound effects, such as sound waves reflected from walls of different materials will produce different sound effects, and sounds from different angles will also have different feelings...
With the launch of A3D 2.0 and the proliferation of interactive games and interactive software that support A3D, A3D applications will be more widely available. Aureal's strength is unquestionable, and A3D's dominance in interactive sound effects cannot be shaken.
Similar technical editor
Department of the famous EAX
Faced with the challenge of A3D, Creative Lab., the industry leader who established the "Soundblaster-compatible" audio specification, has come up with its exclusive technology "Environment Audio", which is an innovative subsidiary EMu is a professional sound technology based on audio and effect technology developed by Hollywood. It relies on the powerful sound processing capability of the main chip EMU10K1 of Soundblaster Live!/value to realize real-time sound reverberation, transposition, echo, and delay. 3D sound effects. Even with the sound input from the microphone, the sound processed by the ambient sound can be played back in real time.
The Environmental Sound Extension Set EAX is a publicly available application programming interface (API) designed to allow game and software developers to use E-mu's Environmental Modeling Technology in the game through EAX. Preset different sound effects parameters of different scenes, such as the lobby, underwater, and indoor, etc., can be easily called when playing the game. When the player is in the room, the preset corresponding ambient sound parameters will be called. The sound becomes occluded, and when the player comes to the hall, the sound becomes empty again, achieving the realistic ambient sound. In addition, for games or software that support A3D, EAX can also call A3D indirectly through DirectX, which also enables realistic interactive sound effects.
The core of the environmental sound is mainly to adjust the audio parameters of Reverb, Chorus, Original Sound and multi-speaker assisted positioning to construct 3D space. So for some games or movies that don't support EAX, the player can adjust the audio parameters through the Mixer's own Mixer to match the sound effects with the software scene. Good results. But in any case, a multi-speaker surround system like PcWorks 4.1 is essential.
For now, although there is not much software supporting EAX, with the consistent appeal of Creative in the industry and the excellent sound performance of EAX in many multimedia software, I believe that its future is very good.
Popular lover SRS
SRS (Sound Retrieval System) is a 3D real-world technology promoted by SRS Labs Inc. SRS believes that the listening range of ordinary stereo is very small, the listener has to sit in an isosceles triangle with the two speakers, and even for the surround sound of multiple speakers, the sounds of the sounds emitted from each speaker are only flat. The sound on the vertical surface is very hollow. The sound processed by the SRS is stereoscopic, and the listener can hear a three-dimensional sound at any angle.
The core of SRS is also the use of HRTF, here we will find out what is HRTF? "HRTF" is an abbreviation for Head-Related Transfer Functions. The HRTF believes that the sound waves from different locations will enter the human ear at different angles. Due to the special structure of the auricle, the sound waves reflected by the auricle will be transmitted to the brain with sound information including frequency, delay, and loudness. The brain determines the spatial location of the sound source by analyzing different sound information. The spatial information provided by the auricle to the brain is called "HRTF". Since the recording device does not have the structure of the human ear, the sound of the plane can be simply recorded, and the three-dimensional information of the original sound on the vertical plane is buried. The principle of SRS is to restore and strengthen these buried three-dimensional spatial information according to the HRTF and use the Frequency Response Correction Curve to make the playback sound stereoscopic, and only one pair of speakers can make people completely in the body. In Hong Hong's broad and realistic sound field.
Compared to A3D and EAX, SRS debuted earlier, and it is widely used in computer multimedia sound cards, speakers and home theaters. And there is no requirement for the software, as long as the sound played back by the SRS sound card or SRS speaker is very three-dimensional, especially if the SRS is connected with the above A3D, EAX or Dolby (such as Live/MX300+SRS speakers), The effect can only be described by the word "shock".
Technical summary editor
In general, these three sounds have their own strengths: A3D wins in interaction, EAX is in sound, and SRS sounds wide and full and can be combined with other 3D sound effects. It seems that the three-nation romance of the 3D sound industry and the situation of small countries such as Q-sound and Spatializer 3D will continue. Who can finally dominate the world? let us wait and see.

The following are some of the sound cards that are officially licensed by Aureal to support 

  • A3D1.0/2.0:
  • Diamond Multimedia: Monster Sound M80/MX100/MX200/MX300, S90
  • Xitel: Storm 3D, StormVX
  • Orchid: NuSound 3D
  • Turtle Beach Systems: Montego A3D
  • Shark Multimedia: Predator 3D, Predator 3D PCI
  • Multiwave: Audio Wave
  • I/O Magic: Magic Wave
  • (ZSB-GiGi)

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