AES New York 2019
Paper Session P1
P1 - Applications in Audio
Wednesday, October 16, 9:00 am — 11:30 am
Kevin Bastyr, Harman International - Novi, MI, USA
P1-1 Personal Sound Zones: A Comparison between Frequency and Time Domain Formulations in a Transportation Context—Lucas Vindrola, LAUM - Les Mans, France; PSA Group - Rueil-Malmaison, France; Manuel Melon, Le Mans Université - Le Mans cedex 9, France; Jean-Christophe Chamard, PSA Group - Rueil-Malmaison, France; Bruno Gazengel, Université du Maine - Le Mans Cedex 9, France; Guy Plantier, LAUM - Les Mans, France
This paper compares the formulation of a least-squares pressure matching algorithm in the frequency and time domains for the generation of Personal Sound Zones (PSZ) for a transportation application. Due to variations in the transportation’s acoustic environment, the calculation time is added to the usually found metrics in the PSZ bibliography (like Acoustic Contrast, Effort, etc.). Both formulations are implemented to control two zones in three configurations (4, 6, and 8 sources), using monopole simulations and anechoic measurements. In spite of not always presenting perfectly causal filters—pre-ringing in some filters occurs in some cases—the frequency domain formulation allows achieving equal levels of Acoustic Contrast, Effort, and Reproduction error more than 500 times faster than the time domain formulation.
Convention Paper 10216
P1-2 Mitigating the Effect of In-Vehicle Road Noise Cancellation on Music Playback—Tao Feng, Harman International - Novi, MI, USA; Kevin Bastyr, Harman International - Novi, MI, USA
A Road Noise Cancellation (RNC) system is an Active Noise Cancellation (ANC) system implemented in a vehicle in order to minimize undesirable road noise inside the passenger cabin. Current RNC systems undesirably affect the frequency response of music playback. The RNC system’s error microphones sense all the sound in the passenger cabin, including the music. Hence, RNC systems will cancel this total sensed sound and not only the road induced noise. A new True Audio algorithm can directly remove the music signal from the error microphone signals and leave only the interior noise portion. In order to correctly estimate the music portion at the error microphones, True Audio implements a novel control topology based on a new multiple channel, real time modeling of the music’s secondary path transfer function. To validate the effectiveness of the proposed algorithm, experimental and numerical simulations were performed. The numerical studies use logs of real sensors mounted on a vehicle forming an RNC system with six reference accelerometers, five control speakers and six error microphones. Both the models and measurements show that the True Audio algorithm preserves the frequency response of music when the RNC system is activated.
Convention Paper 10217
P1-3 Effect of a Global Metronome on Ensemble Accuracy in Networked Music Performance—Robert Hupke, Leibniz Universität Hannover - Hannover, Germany; Lucas Beyer, Leibniz Universität Hannover - Hannover, Germany; Marcel Nophut, Leibniz Universität Hannover - Hannover, Germany; Stephan Preihs, Leibniz Universität Hannover - Hannover, Germany; Jürgen Peissig, Leibniz Universität Hannover - Hannover, Germany
Several rhythmic experiments with pairs drawn from a group of 23 subjects were performed to investigate the effect of a global metronome on the ensemble accuracy in Networked Music Performance (NMP). Artificial delays up to 91 ms were inserted into the audio transmission between the subjects. To investigate the dependencies between delay times, ensemble accuracy and the highly synchronized global metronome, the experiments were evaluated in terms of tempo acceleration, imprecision and subjective judgment of the ensemble play. The results show that the global metronome leads to a stabilization of the tempo acceleration caused by the delay. The imprecision stays constant to a threshold of about 28 ms and 36 ms, depending on the delay compensating strategy the subjects used.
Convention Paper 10218
P1-4 Evaluation of Multichannel Audio in Automobiles versus Mobile Phones—Fesal Toosy, University of Central Punjab - Lahore, Pakistan; Muhammad Sarwar Ehsan, University of Central Punjab - Lahore, Pakistan
Multichannel surround and 3D audio are slowly gaining popularity and eventually commercial content in these formats will become common. Many automobiles still have a stereo sound system with some firmware or software that is capable of rendering multichannel audio into stereo. This paper shows the results of a listening test for multichannel audio conducted in a medium-sized car. The results of this test are compared to the results of a listening test for the same audio excerpts but conducted on a mobile phone with headphones. The results show that on mobile phones, multichannel audio clearly outperforms stereo in terms of perceived audio quality as rated by a user. However in automobiles, multichannel audio only shows marginal improvement in the rated audio quality.
Convention Paper 10219
P1-5 Realizing An Acoustic Vector Network Analyzer—Marcus MacDonell, University of Waikato - Hamilton, Waikato, New Zealand; Jonathan Scott, University of Waikato - Hamilton, Waikato, New Zealand
Acoustic absorption, reflection, and transmission is typically measured using an impedance tube. We present the design and initial measurements of a radically different measurement system. The instrument builds on the rich history and deep mathematics developed in pursuit of electromagnetic Vector-corrected Network Analyzers (VNAs). Using acoustic directional couplers and a traditional VNA mainframe we assembled an “Acoustic Vector Network Analyzer” (AVNA). The instrument measures acoustic scattering parameters, the complex reflection and transmission coefficients, of materials, transmission lines, ported structures, ducts, etc. After the fashion of electromagnetic VNAs we have constructed millimeter-wave measurement heads that span the 800 Hz–2200 Hz (420–150 mm) and 10 kHz–22 kHz (35–15 mm) bands, demonstrating scalability. We present initial measurement results.
Convention Paper 10220