Table 1.
Overview of Current Spatial Audio Reproduction Techniques Aimed to Create Physically Correct or Plausible Sound Fields.
| Reproduction technique | Example systems and listening environments | Number of LSs | Benefits | Drawbacks |
|---|---|---|---|---|
| Binaural technology: Headphones, CTC (Blauert, 1997; Atal et al., 1966) | ITA,a Virtual Acoustics (ITA Aachen, 2018; Wefers, 2015), RAVEN (Schröder, 2011); Sound Scape Renderer (Geier & Spors, 2012); TU Berlin,j WONDER (WONDER Suite, 2017) | Small | Accurate sound source localization, physically correct sound field reproduction in a wide frequency range including room acoustic simulations, flexible source positioning, adaptive sweet spot through head tracking | Tracking system and measurement system for individual HRTFs or individualized HRTFs needed, high processing power for real-time room acoustic simulations needed, coloration artefacts in CTC playback, degraded channel separation especially in nonanechoic rooms |
| Discrete loudspeaker arrays | TUM,b SOFE (Seeber et al., 2010) | Medium to high | Accurate sound source localization, listening with own HRTFs, possible simulation of room reflection patterns | Low simulation flexibility, modelling of “real” sound sources and simulated reflections at LS positions only |
| Panning techniques: VBAP, DBAP, MDAP (Pulkki, 2001), HOA (Daniel, 2000; Williams, 1999; Zotter, 2009); NFC-HOA (Daniel, 2003; Spors et al., 2011) | ITA,a virtual reality laboratory (Pelzer, Sanches, Masiero, & Vorlände, 2011); SoundScape Renderer (Geier & Spors, 2012); IEM,c CUBE (Zmölnig, Sontacchi, & Ritsch, 2003) and mAmbA (IEM mAmbA, 2014); CIRMMT,d VIMIC (Peters, Matthews, Braasch, & McAdams, 2008); IRCAM,e EVERTims (Noisternig et al., 2008), ESPRO 2.0 (Noisternig, Carpentier, & Warusfel, 2012); DTU,f LoRA (Favrot & Buchholz, 2010); Hörtech,g TASCARpro (Grimm, Luberadzka, Herzke, & Hohmann, 2015); HUT,h DIVA (Savioja et al., 1999); T-Labs,i Sound field synthesis toolbox (Wierstorf & Spors, 2012) | Medium to high | Flexible sound source positioning, possible simulation of reflection patterns based on VSSs, fair sound source localization and distance perception | VBAP or DBAP or MDAP: Plausible reproduction, possible discontinuities in VSS movements, increased apparent sound source width, distortion of binaural and monaural cues. (NFC-)HOA: upper frequency limit (spatial aliasing), pronounced sweet area, spectral imbalance, phase distortion, comb filter artefacts, simulation of near-by VSSs only in NFC-HOA systems. |
| Wave field synthesis (Ahrens, 2012; Melchior, 2011; Spors, 2005) | SoundScape Renderer (Geier & Spors, 2012); WONDER (WONDER Suite, 2017); T-Labs,i Sound field synthesis toolbox (Wierstorf & Spors, 2012); Patent DE102007054152 A1 (Schulkrafft, 2002) | Medium to (very) high | Physically correct sound field reproduction up to a spatial aliasing frequency, large sweet area, flexible source positioning, fair localization and distance perception, multilistener suitability | Lack of height information for elevated VSSs, upper frequency limit (spatial aliasing), amplitude and truncation errors, coloration artefacts |
Note. CTC = crosstalk cancellation; HRTF = head-related transfer function; LS = loudspeaker; VBAP = vector base amplitude panning; DBAP = distance-based amplitude panning; MDAP = multiple-direction amplitude panning; HOA = higher-order Ambisonics; NFC-HOA = near-field compensated higher-order Ambisonics; VSS = virtual sound source.
Example reproduction systems for each technique, including their benefits and drawbacks, are provided in addition to an estimation of the amount of LSs required. This table makes no claim to completeness.
Institute of Technical Acoustics, RWTH Aachen University, Germany.
Faculty of Electrical Engineering and Information Technology, Technical University of Munich, Germany.
Institute of Electronic Music and Acoustics, University of Music and Performing Arts Graz, Austria.
Centre for Interdisciplinary Research in Music Media and Technology, McGill University Montréal, Canada.
Institut de Recherche et Coordination Acoustique/Musique, Paris, France.
Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark.
HörTech gGmbH, Competence Center for Hearing Aid Technology, Oldenburg, Germany.
Department of Computer Science, Helsinki University of Technology, Helsinki, Finland.
Telekom Innovation Laboratories, Berlin, Germany. jTechnical University of Berlin, Germany.