3D Sound

Περίληψη Η παρούσα διπλωματική εργασία ερευνά την σύνθεση ηχοτοπίων αμφιωτικού ήχου. Πέραν του κειμένου συνοδεύεται από δυο ηχοτοπιακές συνθέσεις (σπουδές) που αποτελούν το πρακτικό σκέλος της έρευνας. Για την ολοκληρωμένη προσέγγιση του ερευνητικού ζητούμενου, στο θεωρητικό πλαίσιο εξετάζεται η έννοια του ηχοτοπίου και του τρισδιάστατου (αμφιωτικού) ήχου. Παρουσιάζεται μια προτεινόμενη μεθοδολογία σύνθεσης ηχοτοπίων αμφιωτικού ήχου καθώς και μια σειρά από συμπεράσματα που προκύπτουν τόσο από την βιβλιογραφική έρευνα όσο και από την πρακτική εφαρμογή. Λέξεις κλειδιά: ηχοτοπίο, αμφιωτικός ήχος, επαυξημένα ηχοτοπία.

This dissertation determines the knowledge and the characteristics that define a 3D soundscene. The objective is to optimize the perception and reproduction of mu- sical instruments and their diffuse field within a 3D musical production.
Firstly, the contribution of knowledge on acoustic ecology within a 3D sound pro- duction is studied.
This notion is defined and associated with 3D sound, then separated into two cate- gories, environmental and mental acoustic ecology.

Subsequently, a current definition of the diffuse field is proposed. The importance of aesthetic considerations for the diffuse field is emphasized, as is its major role in a 3D sound production. 

In fine, the dissertation addresses all the concepts related to spatial perception:

⁃ The study of psycho and acoustic psychology notions.

⁃ The observation of the anthropological limits of spatial perception.

⁃ The identification of the diffuse field realized by Man.

⁃ The description of perceptual effects in order to best understand the role they
can have on a 3D soundscene.

This knowledge and understanding ensures complete control of a 3D soundscene.
This allows aesthetic and artistic intentions to be even more relevant and coherent with the production choices made by the sound engineer or artist when spatializing sound sources.

In addition, one of the aims of this dissertation is to suggest ideas for the realization of tools to offer greater control over the perception and restitution of a 3D sound- scene, and therefore over 3D music production.

The Immersive Computer-controlled Audio Sound Theater (ICAST, pronounced “eye-cast”) is an on-going research project that addresses performance issues in electroacoustic music. By exploring a variety of differing performance modes through a computer-controlled loudspeaker environment that is malleable, adaptable and intuitive, we are able to explore new and novel metaphors for sound control using both conventional and unconventional interfaces. ICAST is a hardware and software solution, based on a client-server computer control system, commodity audio interface hardware, and high-quality audio amplifiers and loudspeakers. Our system has been deployed for concerts and conferences throughout the past year. Through this initial deployment phase, we have identified critical issues with respect to our client/server systems design, our client software control, and our audio server. This paper identifies both the successes and the struggles we have had, and outlines the solutions we have t...

Despite the recent advantages on multichannel audio coding and playback technologies, 3D audio positioning is frequently required to be performed over legacy stereo loudspeaker setups, due to certain application limitations and restrictions mainly presented in portable and low cost systems. In this work, a 3D audio platform is introduced which allows the real-time conversion of any stereo audio signal to a high-quality immersive audio stream using binaural technology. Due to a number of advanced binaural processing algorithms and features, the proposed conversion platform demonstrates perceptually improved 3D audio spatialization, rendering it suitable for implementing high-quality immersive audio applications.

This paper describes an integration of a 3D sound convolution engine into a telephone conference server software. Our system virtually places participants of a telephone conference to different positions around the listeners by using Head Related Transfer Functions (HRTFs), which helps to identify active speakers in an audio conference. Intelligibility of communication is also increased by making use of the cocktail party effect which helps to concentrate on one specific participant, even if there are more simultaneously active speakers. To support regular telephone systems, we focus in particular on compatibility to existing Voice over IP (VoIP) infrastructure by using standardized protocols like the Session Initiation Protocol (SIP) and the Real-Time Transport Protocol (RTP). Both traditional telephone devices and software clients are put into one heterogeneous conference. While the conference server transmits the down-mixed, mono single-channel conference signal to regular phones, the software clients can receive a stereo-signal enabling full 3D audio.

Sound Field Synthesis reproduces a desired sound field within an extended listening area using up to hundreds of loudspeakers. The perceptual evaluation of such methods is challenging, as many degrees of freedom have to be considered. Binaural Synthesis simulating the loudspeakers over headphones is an effective tool for the evaluation. A prior study has investigated, whether non-individual anechoic binaural synthesis is perceptually transparent enough to evaluate human localisation in sound field synthesis. With the used apparatus, an undershoot for lateral sound sources was observed for real loudspeakers and their binaural simulation. This paper reassesses human localisation for the mentioned technique using a slightly modified setup. The results show that the localisation error decreased and no undershoot was observed.

The article presents the course and the results of an experiment, which aimed at the subjective assessment of the multi-channel impulse responses. The assessment was conducted considering the usefulness of the received responses for the conducting operation of the digital convolution. The resulting sound material is generated for the simulation of the characteristics of the room. In a medium-sized, rectangular reverberation room (74 m 3) a number of measurements of impulse responses were conducted with the use of multi-channel microphone techniques and with the use of SoundField type microphone. In identical conditions the raw sound material was recorded (in conditions of free eld). Next, the convolution was performed between the raw material and the recorded impulse responses. The group of experts, whose members had at least 5 years of experience in the eld of sound engineering, was subjected to the psychoacoustic tests aiming at comparison of the sound materials achieved in the convolution and in the recording.

Paper presented at NEM Summit 2017. In this publication we present two innovative software tools for editing and rendering immersive audio that allow taking the post-production process outside professional studios. The Binaural Home Studio allows to post-produce either 3D or binaural audio while offering special 3D effect functionalities. The contents produced can be listened and therefore tested with head-tracking headphones throughout the Binaural Player. The binaural output produced by the player is interactive, in the sense that adapts to head movements using a head-tracking headphone which gives to both content creators and end-users more realism and sense of presence.

The AES has launched an opportunity to recognize student members who author technical papers. The Student Paper Award Competition is based on the preprint manuscripts accepted for the AES convention. A number of student-authored papers were nominated. The excellent quality of the submissions has made the selection process both challenging and exhilarating. The award-winning student paper will be honored during the Convention, and the student-authored manuscript will be considered for publication in a timely manner for the Journal of the Audio Engineering Society. Nominees for the Student Paper Award were required to meet the following qualifications: (a) The paper was accepted for presentation at the AES 134th Convention. (b) The first author was a student when the work was conducted and the manuscript prepared. (c) The student author's affiliation listed in the manuscript is an accredited educational institution. (d) The student will deliver the lecture or poster presentation at the Convention.

The AES has launched an opportunity to recognize student members who author technical papers. The Student Paper Award Competition is based on the preprint manuscripts accepted for the AES convention. A number of student-authored papers were nominated. The excellent quality of the submissions has made the selection process both challenging and exhilarating. The award-winning student paper will be honored during the Convention, and the student-authored manuscript will be considered for publication in a timely manner for the Journal of the Audio Engineering Society. Nominees for the Student Paper Award were required to meet the following qualifications: (a) The paper was accepted for presentation at the AES 134th Convention. (b) The first author was a student when the work was conducted and the manuscript prepared. (c) The student author's affiliation listed in the manuscript is an accredited educational institution. (d) The student will deliver the lecture or poster presentation at the Convention.

One of the main advantages of Wave Field Synthesis (WFS) is the existence of an extended listening area contrary to the sweet spot in stereophony. At the moment there is only little literature available on the actual localization properties of WFS at different points in the listening area. One reason is the difficulty to place different subjects reliable at different positions. This study systematically investigates the localization performance for WFS at many positions within the listening area. To overcome the difficulty to place subjects, the different listening positions and loudspeaker arrays were simulated by dynamic binaural synthesis. In a pre-study it was verified that this method is suitable to investigate the localization performance in WFS.

Spatial Audio Reproduction Over Patented Headphone AN IMMERSIVE 3D AUDIO HEADSET FOR VIRTUAL AND AUGMENTED REALITY Nguyen Duy Hai1, Santi Peksi1, Rishabh Ranjan3, Jianjun He2, Boon Siang Tan4, Rishabh Gupta1, Woon-Seng Gan1; 1School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore; 2Maxim Integrated, San Jose, United States; 3Immerzen Labs Pte. Ltd., Singapore; 4Sivantos Pte. Ltd, Singapore

The aim of this paper is to examine how to design nonlinear music systems that allow for music events to coincide and correspond with dynamically changing game events. We address the challenges of connecting nonlinear music systems to gameplay and distinguish three approaches for timing time music events and game events: Trail, Sync and Lead. We explore these three approaches in the design case study Gluddle versus The Supervision, a game created by the authors. Our preliminary findings illustrate the benefits of combining Trail, Sync and Lead, positively influencing the game experience, but also the need for extra attention to gameplay balance and technical implementation.

One aspect for a platformer game to be challenging to play is the NPC (Non Playable Character). An NPC is often placed as an obstacle for player to finish at each level. However, an effort must be done to create a behavior of an NPC to be challenging enough and not monotonous. Creating random behavior is one way. But the problem with this approach is a less interactive NPC behavior because of its inability to respond from the game state accordingly. In this paper, we propose an implementation of Sugeno Fuzzy to create behaviors for the NPCs. This methodology takes player’s state and NPC’s state to determine what action will be done. The inputs are player to NPC distance, NPC’s health and player’s weapon ammunition. The outputs are retreat, defense and attack. We applied this methodology in an educational game about Rubela virus vaccination “Healthy Hero” for its boss enemies. Evaluation shows that by applying Sugeno Fuzzy, the NPC behavior can responds to player’s state and its own ...

This study defines the pipeline for digital fashion contents production using CLO 3D, a 3D fashion design software that supports virtual clothing visualization as a cutting-edge simulation technology for fashion, and vuforia, a mobile platform augmented reality (AR) development kit for creating AR applications. The proposed production pipeline is organized in a method to produce a virtual clothing model through CLO 3D software through works of patterns, sewing lines, textures, etc., and AR contents based on computer vision techniques using the functions and properties of vuforia development kits in the Unity engine development environment. In addition, we present application method that can be practically utilized from the perspective of practical users, such as fashion designers and directors, by creating a new type of AR digital fashion contents directly as a flow of the defined production pipeline.

By directly addressing the hearing sensation, auralization is an intuitive means for the assessment and communication of noise scenarios. Authenticity can be fu1iher improved by offering visual information. Currently, various auralization and visualization systems exist, that differ with respect to their sound and image signal generation as well as their reproduction strategy. Within the past few years, the entertainment indushy has launched several virtual reality (YR) products such as head-mounted displays or game engines that appear attractive for applications in environmental sound auralization. This contribution gives an overview of current VR systems and inti·oduces evaluation criteria for comparison and assessment. Focus here is on the application to different railway noise scenes. This involves the generation of stimuli for experimental studies and the use as a demonstrator. To achieve maximal flexibility with respect to scenarios and the reproduction systems, the synthesis ...

The media industry is currently being pulled in the often-opposing directions of increased realism (high resolution, stereoscopic, large screen) and personalization (selection and control of content, availability on many devices). We investigate the feasibility of an end-to-end format-agnostic approach to support both these trends. In this paper, different aspects of a formatagnostic capture, production, delivery and rendering system are discussed. At the capture stage, the concept of layered scene representation is introduced, including panoramic video and 3D audio capture. At the analysis stage, a virtual director component is discussed that allows for automatic execution of cinematographic principles, using feature tracking and saliency detection. At the delivery stage, resolution-independent audiovisual transport mechanisms for both managed and unmanaged networks are treated. In the rendering stage, a rendering process that includes the manipulation of audiovisual content to match the connected display and loudspeaker properties is introduced. Different parts of the complete system are revisited demonstrating the requirements and the potential of this advanced concept.

The purpose of this paper is to analyze the changes of the digital music platforms and digital profit distribution issues which are considered to be the most important part of the application to the Global music industry based on the block chain system. This attempt is not to reveal the success of the block chain and the value judgment in the societies that will come in the future. How to apply the original function of the block chain in the field of the music industry, which has changed a lot in the digital era, this paper focused on what we need to work on. First, I will briefly review the structure and major functions of the block chain system and the crypto-currency, and examine the link between the blockchain and the music industry. In addition, I will focus on some overseas’ cases that are actually applied, and examine the possibility of applying them in the domestic music industry. Through this, I expect that this article will become a cornerstone for discussing the developme...

To progress from surround sound to true 3-D requires an updating of the psychoacoustical theories which underlie current technologies. This paper shows how J.J.Gibson’s ecological approach to perception can be applied to audio perception and used to derive 3-D audio technologies based on intelligent pattern recognition and active hypothesistesting. These technologies are suggested as methods which can be used to generate audio environments that are believable and can be explored.

To progress from surround sound to true 3-D requires a more psychoacoustically complete depiction of the audio environment. This paper defines an important element of the interaction of sounding objects and their environment that we have termed ’ambience labelling information’. However, complex scenes can be cartoonified in order to preserve only perceptually significant information and thus greatly simplify rendering.

We report on on-going work investigating the feasibility of using tissue conduction to evince auditory spatial perception. Early results indicate that it is possible to coherently control externalization, range, directionality (including elevation), movement and some sense of spaciousness without presenting acoustic signals to the outer ear. Signal control techniques so far have utilised discrete signal feeds, stereo and 1st order ambisonic hierarchies. Some deficiencies in frontal externalization have been observed. We conclude that, whilst the putative components of the head related transfer function are absent, empirical tests indicate that coherent equivalents are perceptually utilisable. Some implications for perceptual theory and technological implementations are discussed along with potential practical applications and future lines of enquiry. 1.

Snd3D is a software based real-time 3D sound system based on ambisonics (Gerzon, 1980) and reproduction over loudspeakers aiming at VR and interactive applications. The system is able to perform real-time simulation of direction, distances and movements as well as the acoustic environment. The system is implemented in PD (Puckette, 1996), a graphical programming environment for audio and MIDI processing. One of the novelties with Snd3D is its ability to represent and simulate environmental sounds.

The present work studies the perceptual performance of a Virtual Acoustic Imaging System which utilises loudspeakers, under suboptimal conditions of implementation. The system is based on the binaural reproduction technique over loudspeakers, realised with a crosstalk cancellation network. An experimental procedure is devised in order to obtain the required objective and subjective results for the evaluation of the system's performance. Suboptimal conditions are defined and two major ones are examined. These are the presence of reflections in the reproduction space and the use of non-individualised plant models in the stage of the inverse filtering design. Based on the correlation between subjective and objective results, the perceptual performance is found to degrade severely in the first case and notably in the second case. Design parameters are discussed, in order to improve the performance or relax the control effort of the system.

OMPrisma is a library for the control of sound source spatialization and spatial sound synthesis in the computer-aided composition environment OpenMusic. In this article we describe the basic concepts underlying this library and its integration into compositional workflows ranging from high-level symbolic control structures to spatial sound synthesis and reproduction. A generic framework is presented, consisting of authoring environment, rendering engines and real-time decoding application. We particularly focus on periphonic spatialization processes and the usability of ambisonics from a compositional perspective.

An earlier paper [1] examined the performance of "Classic" horizontal Ambisonic surround sound systems with speakers arranged in regular polygons or as diametrically opposite pairs. We extend the work to non-traditional Ambisonic systems; ITU-R BS775 5.0 layouts supposedly used for domestic surround sound and also non-optimal decode, where the speaker array does not correspond to the decoder. Our interest is in simple enhancements possible with present day technology that could benefit the listener at home.

The idea of No-Input Mixing may appear at first difficult to understand, after all there is no input, yet artists, performers and sound designers have used a variety of approaches using such feedback systems to create music. This paper uses ethnographic approaches to start to understand the methods that people employ when using no-input systems, and in so doing tries to make the invisible, visible. In unpacking some of these techniques we are able to render understandings, of what at first appears to be a random and autonomous set of sounds, as a set of audio features that are controlled, created and are able to be manipulated by a given performer. This is particularly interesting for researchers that involved in the design of new feedback-based instruments, Human Computer Interaction and aleatoric-compositional software.

Spatial localisation of sounding objects is affected not only by auditory cues but also by other modalities such as vision. This is true particularly in the context of distance perception where the number of auditory cues is limited in comparison to e.g. localisation in horizontal and vertical planes. In this study we investigate the influence of vision on the perception of audio. In particular, the effect of incongruent audiovisual cues is explored in the context of the perception of auditory distance in photorealistic virtual reality environments. Preliminary results show that one can allow for a significant mismatch in rendered auditory and visual distance before an audiovisual scene ceases to be perceived as consistent by most of the participants.

By convolving an audio stream with a given pair of impulse responses between a source position and the two ears, virtual sound scenes can be created over headphones. Typically, the set of these filters for an ensemble of spatial positions, termed the Head-Related Impulse Response (HRIR) is used to render position information of a sound object to a listener. However, HRIRs are measured in free-field conditions, ignoring room reflections. In the real world, multiple reflections and reverberation exist, producing complex rich sound spaces. Including room reflections and reverberation with the HRIR results in a binaural room impulse response (BRIR). The length of a given BRIR depend on the shape and volume of the room, with BRIRs having typical duration of several seconds, resulting in computationally long processing. When the virtual environment is updated in response to head/body movement, BRIRs need to be updated according to the relative direction of a sound object within the perceptual detection threshold of system latency. This poses complications for mobile devices where processing power is limited, such as the case of augmented reality. In this paper, the architecture of a new signal processing method by distributed computers is proposed for convolution of BRIRs applicable to such conditions.

We report on on-going work investigating the feasibility of using tissue conduction to evince auditory spatial perception. Early results indicate that it is possible to coherently control externalization, range, directionality (including elevation), movement and some sense of spaciousness without presenting acoustic signals to the outer ear. Signal control techniques so far have utilised discrete signal feeds, stereo and 1st order ambisonic hierarchies. Some deficiencies in frontal externalization have been observed. We conclude that, whilst the putative components of the head related transfer function are absent, empirical tests indicate that coherent equivalents are perceptually utilisable. Some implications for perceptual theory and technological implementations are discussed along with potential practical applications and future lines of enquiry.

Traditional multichannel-reproduction systems are mainly used for recreation of pantophonic soundfields. Fully periphonic reproduction has been limited by computational power to manipulate large numbers of audio-channels as well as needed speaker-layouts. Since in the last years digital hardware has become fast enough to meet the computational requirements, a medium-sized concert-hall for reproduction of periphonic electro-acoustic music, the so called IEM-Cube, has been installed at the the IEM. The room is equipped with a hemisphere consisting of 24 loudspeakers, that allows reproduction of three-dimensional soundfields following ambisonic principles of at least 3rd order. To make use of this, a linear 3Dmixing system on PC-basis has been developed. The system may be used as a production-tool for periphonic mixing into a set of ambisonic-channels, as a reproduction-environment for recreating a 3D-soundfield out of such set of ambisonic-encoded channels, and as a live-instrument th...

Harmony of the Spheres is a concert programme based on cosmology during the renaissance. Historic philosophical and astronomical concepts from ancient Greece until the modern age are accessed through the music of the 16th and 20th century. The five musicians of the ensemble ORLANDOviols play on violas da gamba of several sizes, but also employ the potential of electronics and digital signal processing to craft musical concepts in space. Low-delay real-time spatial processing is applied to the instruments and presented via a multi-channel speaker setup.

This thesis is the account of cross-disciplinary research that explores spatial audio experiences in multimodal contexts. The practice of arranging dynamical modifications of spatial attributes of sound to create impressions of movement through sound has been applied to dance choreography and theatre. Using wave field synthesis and ambisonics technologies for spatial audio sound playback, two projects have been created: Stranded (2013), a joint choreography for three dancers and sonic movement in collaboration with choreographer Jalianne Li, and I Hear You See Me (2014), an audiovisual installation featuring participatory theatre, sonic movement, and motion graphics, in collaboration with theatre artist Silvia Mercuriali and visual artist Simon Wilkinson. These works are the outcome of a complex collaborative exchange between the author and the mentioned artists and a comparison at multiple levels (aesthetic, technical, cultural) between the different disciplines involved, and propo...

The media industry is currently being pulled in the often-opposing directions of increased realism (high resolution, stereoscopic, large screen) and personalization (selection and control of content, availability on many devices). We investigate the feasibility of an end-to-end format-agnostic approach to support both these trends. In this paper, different aspects of a formatagnostic capture, production, delivery and rendering system are discussed. At the capture stage, the concept of layered scene representation is introduced, including panoramic video and 3D audio capture. At the analysis stage, a virtual director component is discussed that allows for automatic execution of cinematographic principles, using feature tracking and saliency detection. At the delivery stage, resolution-independent audiovisual transport mechanisms for both managed and unmanaged networks are treated. In the rendering stage, a rendering process that includes the manipulation of audiovisual content to match the connected display and loudspeaker properties is introduced. Different parts of the complete system are revisited demonstrating the requirements and the potential of this advanced concept.

The media industry is currently being pulled in the often-opposing directions of increased realism (high resolution, stereoscopic, large screen) and personalization (selection and control of content, availability on many devices). We investigate the feasibility of an end-to-end format-agnostic approach to support both these trends. In this paper, different aspects of a formatagnostic capture, production, delivery and rendering system are discussed. At the capture stage, the concept of layered scene representation is introduced, including panoramic video and 3D audio capture. At the analysis stage, a virtual director component is discussed that allows for automatic execution of cinematographic principles, using feature tracking and saliency detection. At the delivery stage, resolution-independent audiovisual transport mechanisms for both managed and unmanaged networks are treated. In the rendering stage, a rendering process that includes the manipulation of audiovisual content to match the connected display and loudspeaker properties is introduced. Different parts of the complete system are revisited demonstrating the requirements and the potential of this advanced concept.

co-editors of the International Computer Music Association's Array newsletter, collected and edited the original stimulus and several replies for their publication. We reproduce it here with minor edits as a "guest editorial," with thanks to the authors and editors.]

The paper describes the recording/reproduction technique and the subjective listening experiment aimed to the assessment of the effect of the background noise on the perceived quality of the sound being reproduced inside a car. The noise inside 3 different cars was recorded at various speeds both with a binaural microphone and with a Soundfield microphone. These background noise recordings are reproduced inside a special listening room, by means of a very sophisticated reproduction chain, designed so that at the ears of the listeners the same sound pressure is presented as inside the original car. A computer-based system is finally employed for collecting subjective responses to sound stimula, constituted by the reproduction of music or speech on an automotive sound system in presence of the background noise.

Multimodal sensory presentations are now commonplace in many aspects of everyday life. Cinematic or gaming experiences are probably two of the most popular examples. In some of these applications, the intention is to immerse the user so that the perceived virtual ...

This article approaches binaural interactive environments from an artistic research perspective. Beyond content production, an aesthetic reflection of binaural media requires pervasive access to digital processing means and ways to employ them in composition. However, most conventional workflows separate media-specific rendering algorithms from object-based scene authoring. Such a delimitation between binaural engineering and its application restricts transdisciplinary creation that crosses both areas. This article assumes that the full potential of immersive media cannot be explored without investigating technology in the context of aesthetic experience. A case study is presented in which artistic references are regarded together with its technical realization. Contemporary user experience evaluation methods are adopted and refined with reference to the aims of the artist. A subsequent revision of the work is discussed along with implementation adjustments and conceptual alteration...

This paper describes a computational model for the prediction of perceived spatial quality for reproduced sound at arbitrary locations in the listening area. The model is specifically designed to evaluate distortions in the spatial domain such as changes in source location, width and envelopment. Maps of perceived spatial quality across the listening area are presented from our initial results.

Ambiophonics, Panorambiophonics, and Periambiophonics are related surround sound paradigms that reliably deliver up to full 360-degree spherical localization for both direct and ambient sound via two, four, or six DVD/SACD/MLP/DTS/Dolby/ADAT coding/media channels. They reproduce old or new, standard, 2, 4, 6, or ITU 5.1-channel music discs with unprecedented spatial realism and binaural-like localization accuracy via direct sound radiating front/rear/overhead stage-producing Ambiopoles and virtually any desired number of ambience surround speakers. Alternatively, superior acoustic recordings can be made using the described Ambiophones (or using algorithms if fabricated) to capture images of startling depth and presence for music in the round, 3D movie sound tracks, virtual reality, or electronic music soundscapes. Six-channel Periambiophonics adds elevated direct sound to the fully spherical hall ambience vectors already provided by basic Ambiophonics which drives essentially any number of hall ambience speakers regardless of their positions. All the versions of surround Ambiophonics easily deliver a "you-are-there", psychoacoustically correct, home listening experience, via home theater media, albeit best limited to one or two listeners. .

Ambiophonics, Panorambiophonics, and Periambiophonics are related surround sound paradigms that reliably deliver up to full 360-degree spherical localization for both direct and ambient sound via two, four, or six DVD/SACD/MLP/DTS/Dolby/ADAT coding/media channels. They reproduce old or new, standard, 2, 4, 6, or ITU 5.1-channel music discs with unprecedented spatial realism and binaural-like localization accuracy via direct sound radiating front/rear/overhead stage-producing Ambiopoles and virtually any desired number of ambience surround speakers. Alternatively, superior acoustic recordings can be made using the described Ambiophones (or using algorithms if fabricated) to capture images of startling depth and presence for music in the round, 3D movie sound tracks, virtual reality, or electronic music soundscapes. Six-channel Periambiophonics adds elevated direct sound to the fully spherical hall ambience vectors already provided by basic Ambiophonics which drives essentially any number of hall ambience speakers regardless of their positions. All the versions of surround Ambiophonics easily deliver a "you-are-there", psychoacoustically correct, home listening experience, via home theater media, albeit best limited to one or two listeners. .

Several types of microphone techniques exist to record music performances for surround sound reproduction. Variations between different techniques are found in the distance and angle between the microphones, and the choice of directivity patterns. All the arrays are targeted to produce an accurate spatial impression at the sweet spot, the listening area of a speaker arrangement in which the spatial cues are reproduced with sufficient accuracy. The aim of this investigation is to determine how different microphone techniques affect the size of the sweet spot. In particular, the common belief that spaced techniques lead to larger sweet spot areas than coincidence and near-coincident techniques is investigated. For this purpose recordings which was made with 3 different microphone techniques simultaneously are presented through a surround loudspeaker set-up in two different large rooms. Binaural recordings were produced to capture sound fields at different positions inside the listening area. In a psychoacoustic experiment, listeners were asked to rate these binaural recordings according to the spatial impression provided by different recording techniques. The results of the listening test are also compared to the data of an binaural auditory model simulation.