APL at the International Congress on Acoustics 2022

Hyunkook Lee was invited to give a special lecture on spatial and immersive audio at the ICA Student Camp, which took place one day before the main conference started. 40+ students from different countries attended the 3-hour-long lecture titled “Psychoacoustic Engineering in Spatial and Immersive Audio”. The session first discussed what it means by “immersive” audio, based on Hyunkook’s conceptual model of immersive experience in extended reality , followed by various psychoacoustic factors that need to be considered to make spatial audio truly immersive. This talk was accompanied with the demonstrations of 3D sound recording examples that were binauralsed using the APL’s upcoming binaural renderer.

Alan Pawlak, a PhD student at the APL, presented a paper “Spatial segmentation of an early part of the room impulse response into prominent sound events” in a poster session A12 Room Acoustics. This work proposes a new method to quantise residual information to the directions of arrival of prominent early reflections within the framework of the spatial decomposition method (SDM). The listening test results suggest that there is no audible difference between the original SDM and the proposed method. This finding allows for the efficient and perceptually accurate segmentation and manipulation of spatial information obtained from spatial room impulse responses. Alan’s project (OpAurEx) is fully funded by Genelec and the University of Huddersfield.

On Day 4, Hyunkook Lee and Dale Johnson presented their paper “Playback level calibration by hand rubbing for remote listening test” in the session A11: Psychoacoustics. This work formally measured and reported the sound pressure levels of hand-rubbing for the first time in history, and a new method to calibrate the sound playback level using hand-rubbing in a remote listening test was proposed. The hand-rubbing method had already been used in an online listening test platform, but there had been no formal data provided and the validity of the method had not been confirmed. This research aims to validate the method and further provide a procedural guideline to use the method in remote listening tests. The second part of the study, which is to examine the inter-subject consistency of levels matched using the method, will be conducted and presented this year.

On the last day of the conference, Hyunkook also presented a short paper “Online acoustic recording education using MARRS” in A22: Education, Public outreach and History in Acoustics. This session introduced the MARRS for Web, an interactive app for simulating and auralising recordings made using stereo microphone techniques. The algorithm is based on Hyunkook’s previous work on time-level difference trade-off for stereophonic localisation, and the Web app was developed by Nikita Goddard, a former Masters by Research student at the APL.  This app was found extremely useful for teaching sound recording during the pandemic period when physical recording sessions were not allowed. MARRS for Web is used a lot to help students and sound engineers understand the concept of stereophonic recording angle and the implications of microphone configurations on stereophonic imaging.

The papers we presented can be found in the links below.

Pawlak. A. and Lee, H. “Spatial Segmentation of An Early Part of The Room Impulse Response into Prominent Sound Events” In Proceedings of International Congress on Acoustics (ICA) 2022.

Lee, H. and Johnson, D. “Playback level calibration by hand rubbing for remote listening test” In Proceedings of International Congress on Acoustics (ICA) 2022.

Lee, H. and Goddard, N. “Online acoustic recording education using MARRS” In Proceedings of International Congress on Acoustics (ICA) 2022.