Research Publications

The Impact of Varying Frequency on the Perception of Audio-on-Audio Interference in Personal Sound Zones

Author(s): Luo, Jessica S; Roginska, Agnieszka

Paper Type: AES Convention Paper

Publication Date: 2024-10-14

Permalink: https://aes2.org/publications/elibrary-page/?id=23089

Abstract:

A personal sound zone (PSZ) is a section in a space in which audio content can be received and customized for a listener separate from other listeners when using the same loudspeaker system. The approach for this is the creation of a bright zone (BZ) and a dark zone (DZ) where the desired output is targeted and where the sound pressure level of that desired output is reduced respectively. When sharing a space and playback system, interference will occur as different content is played simultaneously. Previous research in minimizing this audio-on-audio interference and evaluating the perceptual experience of it has led to the determination of thresholds of acceptability between programs for certain listening tasks. However, further investigation within the tasks, specifically frequency content, has not been explored. This study investigates how varying frequency in classical and jazz program content impacts one`s perception of audio-on-audio interference in PSZs. With the BZ as broadband content and the DZ as band-limited content, 4 attributes concerning audio-on-audio interference were rated comparing the accepted thresholds and an optional new threshold made by participants. From the responses, the accepted thresholds were not robust across all frequency content and it is suggested that separate thresholds are needed to consider different hearing sensitivities across the frequency spectrum, especially at higher frequencies. This investigation evaluated predetermined thresholds of acceptability on the perception of audio-on-audio interference in personal sound zones, suggesting that further work is warranted to create new values that consider varying frequency content.

Impact of Steered Height Microphones of Large Sources on One`s Immersive Listening Experience

Author(s): Luo, Jessica S; Geluso, Paul

Paper Type: AES Convention Paper

Publication Date: 2025-10-14

Permalink: https://aes2.org/publications/elibrary-page/?id=23098

Abstract:

When recording immersive performances, height microphones are placed strategically to capture the image realistically. Of commercial immersive recording arrays capturing large ensembles, most arrays have height microphones placed non-coincident from the horizontal layer. For solo recordings of large sound sources like the piano or drumset, the spatial image may be treated similar to that of capturing a large ensemble -- as a wall of sound. To allow for more control in the post-processing stage, height microphones that can be steered during mixing are proposed and evaluated as a technique for immersive recordings of large sound sources. Through subjective listening tests, three differently-steered height microphone layers were compared to one another as well as a reference non-coincident height microphone layer on perceived realism, source width, source size, height, and tone color of a solo piano and solo drumset. The findings of this investigation conclude that differently-steered height microphones did not significantly impact the perceived realism of these two instruments. Additionally, different directions were preferred for each instrument.

Spatial Sampling of Binaural Room Transfer Functions for Head-Tracked Personal Sound Zones

Author(s): Qiao, Yue; Luo, Jessica; Choueiri, Edgar Y.

Paper Type: JAES Journal Article

Publication Date: 2024-07-09

Permalink: https://aes2.org/publications/elibrary-page/?id=22643

Abstract:

The spatial sampling of binaural room transfer functions that vary with listener movements, as required for rendering personal sound zone (PSZ) with head tracking, was experimentally investigated regarding its dependencies on various factors. Through measurements of the binaural room transfer functions in a practical PSZ system with either translational or rotational movements of one of the two mannequin listeners, the PSZ filters were generated along the measurement grid and then spatially downsampled to different resolutions, at which the isolation performance of the system was numerically simulated. It was found that the spatial sampling resolution generally depends on factors such as the moving listener’s position, frequency band of the rendered audio, and perturbation caused by the other listener. More specifically, the required sampling resolution is inversely proportional to the distance either between two listeners or between the moving listener and the loudspeakers and is proportional to the frequency of the rendered audio. The perturbation caused by the other listener may impair both the isolation performance and filter robustness against movements. Furthermore, two crossover frequencies were found to exist in the system, which divide the frequency band into three sub-bands, each with a distinctive requirement for spatial sampling.

The Impact of Height Microphone Layer Position on Perceived Realism of Organ Recording Reproduction

Author(s): Luo, Jessica; Treanor, Garrett

Paper Type: AES Convention Paper

Publication Date: 2024-09-27

Permalink: https://aes2.org/publications/elibrary-page/?id=22692

Abstract:

For on-site immersive recordings, height microphones are often placed carefully to avoid a distorted or unrealistic image, with many established immersive microphone arrays placing the height microphones 1.5 m or less above the horizontal layer. However, with an instrument so acoustically symbiotic with its space as the pipe organ, the impact of non-coincident height microphone placement has not previously been explored in-depth. Despite this, the pipe organs radiation characteristics may benefit from non-coincident height microphone placement, providing subjectively improved tone color without sacrificing perceived realism. Subjective listening tests were conducted comparing a pipe organ recording with coincident and non-coincident height microphone positions. The findings of this case study conclude that non-coincident height microphone placement does not significantly impact perceived realism of the immersive organ recording.

Exploring Immersive Recording and Reproduction Methods for Pipe Organs

Author(s): Treanor, Garrett; Luo, Jessica; Tsuaye, Jeremy; Songmuang, Parichat; Wu, Yi; Jaimes, Angel; Bobby, Joel; Li, Zhinuo

Paper Type: AES Convention Express Paper

Publication Date: 2024-09-27

Permalink: https://aes2.org/publications/elibrary-page/?id=22728

Abstract:

The pipe organ is often underrepresented in classical music recordings, particularly in immersive audio formats. This paper explores a novel approach to recording and reproducing the organ for immersive formats using a modified Bowles Array. Key considerations for immersive recording and reproduction are examined, including the balance between aestheticism and realism, the role of the LFE channel, and the acoustic characteristics of the recording and reproduction environments, as well as the instrument itself. The findings aim to enhance the immersive audio experience of pipe organ music and provide valuable insights for developing standards in immersive recording and reproduction methods for pipe organ performances.