scholarly journals Binaural Rendering with Measured Room Responses: First-Order Ambisonic Microphone vs. Dummy Head

2020 ◽  
Vol 10 (5) ◽  
pp. 1631 ◽  
Author(s):  
Markus Zaunschirm ◽  
Matthias Frank ◽  
Franz Zotter

To improve the limited degree of immersion of static binaural rendering for headphones, an increased measurement effort to obtain multiple-orientation binaural room impulse responses (MOBRIRs) is reasonable and enables dynamic variable-orientation rendering. We investigate the perceptual characteristics of dynamic rendering from MOBRIRs and test for the required angular resolution. Our first listening experiment shows that a resolution between 15 ∘ and 30 ∘ is sufficient to accomplish binaural rendering of high quality, regarding timbre, spatial mapping, and continuity. A more versatile alternative considers the separation of the room-dependent (RIR) from the listener-dependent head-related (HRIR) parts, and an efficient implementation thereof involves the measurement of a first-order Ambisonic RIR (ARIR) with a tetrahedral microphone. A resolution-enhanced ARIR can be obtained by an Ambisonic spatial decomposition method (ASDM) utilizing instantaneous direction of arrival estimation. ASDM permits dynamic rendering in higher-order Ambisonics, with the flexibility to render either using dummy-head or individualized HRIRs. Our comparative second listening experiment shows that 5th-order ASDM outperforms the MOBRIR rendering with resolutions coarser than 30 ∘ for all tested perceptual aspects. Both listening experiments are based on BRIRs and ARIRs measured in a studio environment.

2020 ◽  
Vol 10 (11) ◽  
pp. 3747
Author(s):  
Markus Zaunschirm ◽  
Franck Zagala ◽  
Franz Zotter

Can auralization of a highly directional source in a room succeed if it employs a room impulse response (RIR) measurement or simulation relying on a first-order directional source, only? This contribution presents model and evaluation of a source-and-receiver-directional Ambisonics RIR capture and processing approach (SRD ARIR) based on a small set of responses from a first-order source to a first-order receiver. To enhance the directional resolution, we extend the Ambisonic spatial decomposition method (ASDM) to upscale the first-order resolution of both source and receiver to higher orders. To evaluate the method, a listening experiment was conducted based on first-order SRD-ARIR measurements, into which the higher-order directivity of icosahedral loudspeaker’s (IKO) was inserted as directional source of well-studied perceptual effects. The results show how the proposed method performs and compares to alternative rendering methods based on measurements taken in the same acoustic environment, e.g., multiple-orientation binaural room impulse responses (MOBRIRs) from the physical IKO to the KU-100 dummy head, or higher-order SRD ARIRs from IKO to em32 Eigenmike. For optimal externalization, our experiments exploit the benefits of virtual reality, using a highly realistic visualization on head-mounted-display, and a user interface to report localization by placing interactive visual objects in the virtual space.


Author(s):  
Nemat Dalir

Singular nonlinear initial-value problems (IVPs) in first-order and second-order partial differential equations (PDEs) arising in fluid mechanics are semianalytically solved. To achieve this, the modified decomposition method (MDM) is used in conjunction with some new inverse differential operators. In other words, new inverse differential operators are developed for the MDM and used with the MDM to solve first- and second-order singular nonlinear PDEs. The results of the solutions by the MDM together with new inverse operators are compared with the existing exact analytical solutions. The comparisons show excellent agreement.


2019 ◽  
Vol 9 (3) ◽  
pp. 460 ◽  
Author(s):  
Song Li ◽  
Roman Schlieper ◽  
Jürgen Peissig

Several studies show that the reverberation and spectral details in direct sounds are two essential cues for perceived externalization of virtual sound sources in reverberant environments. The present study investigated the role of these two cues in contralateral and ipsilateral ear signals on perceived externalization of headphone-reproduced binaural sound images at different azimuth angles. For this purpose, seven pairs of non-individual binaural room impulse responses (BRIRs) were measured at azimuth angles of −90°, −60°, −30°, 0°, 30°, 60°, and 90° in a listening room. The magnitude spectra of direct parts were smoothed, and the reverberation was removed, either in left or right ear BRIRs. Such modified BRIRs were convolved with a speech signal, and the resulting binaural sounds were presented over headphones. Subjects were asked to assess the degree of perceived externalization for the presented stimuli. The result of the subjective listening experiment revealed that the magnitude spectra of direct parts in ipsilateral ear signals and the reverberation in contralateral ear signals are important for perceived externalization of virtual lateral sound sources.


1925 ◽  
Vol 18 (3) ◽  
pp. 141-163
Author(s):  
Edwin W. Schreiber

It will be the function of this chapter to reveal the results of the relationships of the various abilities examined in Chapter II as measured by co-efficients of correlation, both of the zero and the first order (partial correlation). It will also deal in a limited degree with regression lines and equations.


Acta Acustica ◽  
2022 ◽  
Vol 6 ◽  
pp. 1
Author(s):  
Pedro Lladó ◽  
Petteri Hyvärinen ◽  
Ville Pulkki

Auditory localisation accuracy may be degraded when a head-worn device (HWD), such as a helmet or hearing protector, is used. A computational method is proposed in this study for estimating how horizontal plane localisation is impaired by a HWD through distortions of interaural cues. Head-related impulse responses (HRIRs) of different HWDs were measured with a KEMAR and a binaural auditory model was used to compute interaural cues from HRIR-convolved noise bursts. A shallow neural network (NN) was trained with data from a subjective listening experiment, where horizontal plane localisation was assessed while wearing different HWDs. Interaural cues were used as features to estimate perceived direction and position uncertainty (standard deviation) of a sound source in the horizontal plane with the NN. The NN predicted the position uncertainty of localisation among subjects for a given HWD with an average estimation error of 1°. The obtained results suggest that it is possible to predict the degradation of localisation ability for specific HWDs in the frontal horizontal plane using the method.


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