MDPI - Publisher of Open Access Journals

17 pages, 3474 KiB

Open AccessCommunication

Listen to the Brain–Auditory Sound Source Localization in Neuromorphic Computing Architectures

by Daniel Schmid, Timo Oess and Heiko Neumann

Sensors 2023, 23(9), 4451; https://doi.org/10.3390/s23094451 - 2 May 2023

Cited by 3 | Viewed by 2637

Conventional processing of sensory input often relies on uniform sampling leading to redundant information and unnecessary resource consumption throughout the entire processing pipeline. Neuromorphic computing challenges these conventions by mimicking biology and employing distributed event-based hardware. Based on the task of lateral auditory sound source localization (SSL), we propose a generic approach to map biologically inspired neural networks to neuromorphic hardware. First, we model the neural mechanisms of SSL based on the interaural level difference (ILD). Afterward, we identify generic computational motifs within the model and transform them into spike-based components. A hardware-specific step then implements them on neuromorphic hardware. We exemplify our approach by mapping the neural SSL model onto two platforms, namely the IBM TrueNorth Neurosynaptic System and SpiNNaker. Both implementations have been tested on synthetic and real-world data in terms of neural tunings and readout characteristics. For synthetic stimuli, both implementations provide a perfect readout (

100 %

accuracy). Preliminary real-world experiments yield accuracies of

78 %

(TrueNorth) and

13 %

(SpiNNaker), RMSEs of

41^{\circ}

and

39^{\circ}

, and MAEs of

18^{\circ}

and

29^{\circ}

, respectively. Overall, the proposed mapping approach allows for the successful implementation of the same SSL model on two different neuromorphic architectures paving the way toward more hardware-independent neural SSL. Full article

(This article belongs to the Special Issue Advanced Technology in Acoustic Signal Processing)

► Show Figures

Figure 1

18 pages, 1140 KiB

Open AccessArticle

A Diversity Combination Model Incorporating an Inward Bias for Interaural Time-Level Difference Cue Integration in Sound Lateralization

by Sina Mojtahedi, Engin Erzin and Pekcan Ungan

Appl. Sci. 2020, 10(18), 6356; https://doi.org/10.3390/app10186356 - 12 Sep 2020

Cited by 1 | Viewed by 2460

Abstract

A sound source with non-zero azimuth leads to interaural time level differences (ITD and ILD). Studies on hearing system imply that these cues are encoded in different parts of the brain, but combined to produce a single lateralization percept as evidenced by experiments indicating trading between them. According to the duplex theory of sound lateralization, ITD and ILD play a more significant role in low-frequency and high-frequency stimulations, respectively. In this study, ITD and ILD, which were extracted from a generic head-related transfer functions, were imposed on a complex sound consisting of two low- and seven high-frequency tones. Two-alternative forced-choice behavioral tests were employed to assess the accuracy in identifying a change in lateralization. Based on a diversity combination model and using the error rate data obtained from the tests, the weights of the ITD and ILD cues in their integration were determined by incorporating a bias observed for inward shifts. The weights of the two cues were found to change with the azimuth of the sound source. While the ILD appears to be the optimal cue for the azimuths near the midline, the ITD and ILD weights turn to be balanced for the azimuths far from the midline. Full article

(This article belongs to the Section Acoustics and Vibrations)

► Show Figures

Figure 1

26 pages, 559 KiB

Open AccessArticle

Evaluating the Impact of Age, Acoustic Exposure, and Electrical Stimulation on Binaural Sensitivity in Adult Bilateral Cochlear Implant Patients

by Tanvi Thakkar, Sean R. Anderson, Alan Kan and Ruth Y. Litovsky

Brain Sci. 2020, 10(6), 406; https://doi.org/10.3390/brainsci10060406 - 26 Jun 2020

Cited by 17 | Viewed by 3739

Abstract

Deafness in both ears is highly disruptive to communication in everyday listening situations. Many individuals with profound deafness receive bilateral cochlear implants (CIs) to gain access to spatial cues used in localization and speech understanding in noise. However, the benefit of bilateral CIs, in particular sensitivity to interaural time and level differences (ITD and ILDs), varies among patients. We measured binaural sensitivity in 46 adult bilateral CI patients to explore the relationship between binaural sensitivity and three classes of patient-related factors: age, acoustic exposure, and electric hearing experience. Results show that ILD sensitivity increased with shorter years of acoustic exposure, younger age at testing, or an interaction between these factors, moderated by the duration of bilateral hearing impairment. ITD sensitivity was impacted by a moderating effect between years of bilateral hearing impairment and CI experience. When age at onset of deafness was treated as two categories (<18 vs. >18 years of age), there was no clear effect for ILD sensitivity, but some differences were observed for ITD sensitivity. Our findings imply that maximal binaural sensitivity is obtained by listeners with a shorter bilateral hearing impairment, a longer duration of CI experience, and potentially a younger age at testing. 198/200. Full article

(This article belongs to the Special Issue Central Auditory Plasticity)

► Show Figures

Figure 1

21 pages, 12545 KiB

Open AccessArticle

Interaural Level Difference Optimization of Binaural Ambisonic Rendering

by Thomas McKenzie, Damian T. Murphy and Gavin Kearney

Appl. Sci. 2019, 9(6), 1226; https://doi.org/10.3390/app9061226 - 23 Mar 2019

Cited by 10 | Viewed by 5037

Abstract

Ambisonics is a spatial audio technique appropriate for dynamic binaural rendering due to its sound field rotation and transformation capabilities, which has made it popular for virtual reality applications. An issue with low-order Ambisonics is that interaural level differences (ILDs) are often reproduced with lower values when compared to head-related impulse responses (HRIRs), which reduces lateralization and spaciousness. This paper introduces a method of Ambisonic ILD Optimization (AIO), a pre-processing technique to bring the ILDs produced by virtual loudspeaker binaural Ambisonic rendering closer to those of HRIRs. AIO is evaluated objectively for Ambisonic orders up to fifth order versus a reference dataset of HRIRs for all locations on the sphere via estimated ILD and spectral difference, and perceptually through listening tests using both simple and complex scenes. Results conclude AIO produces an overall improvement for all tested orders of Ambisonics, though the benefits are greatest at first and second order. Full article

(This article belongs to the Special Issue Psychoacoustic Engineering and Applications)

► Show Figures

Figure 1

20 pages, 908 KiB

Open AccessArticle

Binaural Sound Localizer for Azimuthal Movement Detection Based on Diffraction

by Keonwook Kim and Anthony Choi

Sensors 2012, 12(8), 10584-10603; https://doi.org/10.3390/s120810584 - 3 Aug 2012

Cited by 8 | Viewed by 5971

Abstract

Sound localization can be realized by utilizing the physics of acoustics in various methods. This paper investigates a novel detection architecture for the azimuthal movement of sound source based on the interaural level difference (ILD) between two receivers. One of the microphones in the system is surrounded by barriers of various heights in order to cast the direction dependent diffraction of the incoming signal. The gradient analysis of the ILD between the structured and unstructured microphone demonstrates the rotation directions as clockwise, counter clockwise, and no rotation of the sound source. Acoustic experiments with different types of sound source over a wide range of target movements show that the average true positive and false positive rates are 67% and 16%, respectively. Spectral analysis demonstrates that the low frequency delivers decreased true and false positive rates and the high frequency presents increases of both rates, overall. Full article

(This article belongs to the Section Physical Sensors)

► Show Figures

Search Results (5)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI

Saved Queries

Search Filter Reset All

Years

Feature Papers

Subjects

Journals

Article Types

Countries / Regions

Search Results (5)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI