scholarly journals Sound localization in headphone reproduction by simulating transfer functions from the sound source to the external ear.

1991 ◽  
Vol 12 (5) ◽  
pp. 203-216 ◽  
Author(s):  
Jun'ichi Kawaura ◽  
Yoiti Suzuki ◽  
Futoshi Asano ◽  
Toshio Sone
Keyword(s):  
Sound Localization ◽  
Sound Source ◽  
Transfer Functions ◽  
External Ear

scholarly journals Short-term effects of sound localization training in virtual reality

2017 ◽  
Author(s):  
Mark A. Steadman ◽  
Chungeun Kim ◽  
Jean-Hugues Lestang ◽  
Dan F. M. Goodman ◽  
Lorenzo Picinali
Keyword(s):  
Sound Localization ◽  
Sound Source ◽  
Game Design ◽  
Transfer Functions ◽  
Polar Angle ◽  
Active Listening ◽  
Head Tracking ◽  
Localization Accuracy ◽  
Design Elements ◽  
Listening Group

ABSTRACTHead-related transfer functions (HRTFs) capture the direction-dependant way that sound interacts with the head and torso. In virtual audio systems, which aim to emulate these effects, non-individualized, generic HRTFs are typically used leading to an inaccurate perception of virtual sound location. Training has the potential to exploit the brain’s ability to adapt to these unfamiliar cues. In this study, three virtual sound localization training paradigms were evaluated; one provided simple visual positional confirmation of sound source location, a second introduced game design elements (“gamification”) and a final version additionally utilized head-tracking to provide listeners with experience of relative sound source motion (“active listening”). The results demonstrate a significant effect of training after a small number of short (12-minute) training sessions, which is retained across multiple days. Gamification alone had no significant effect on the efficacy of the training, but active listening resulted in a significantly greater improvements in localization accuracy. In general, improvements in virtual sound localization following training generalized to a second set of non-individualized HRTFs, although some HRTF-specific changes were observed in polar angle judgement for the active listening group. The implications of this on the putative mechanisms of the adaptation process are discussed.

scholarly journals Influence of head morphology and natural postures on sound localization cues in crocodilians

2019 ◽  
Vol 6 (7) ◽  
pp. 190423 ◽  
Author(s):  
L. Papet ◽  
N. Grimault ◽  
N. Boyer ◽  
N. Mathevon
Keyword(s):  
Sound Localization ◽  
Sound Source ◽  
Social Life ◽  
Transfer Functions ◽  
Azimuthal Angle ◽  
Sound Sources ◽  
Low Frequencies ◽  
Top Predators ◽  
Head Morphology ◽  
Interaural Level Differences

As top predators, crocodilians have an acute sense of hearing that is useful for their social life and for probing their environment in hunting situations. Although previous studies suggest that crocodilians are able to localize the position of a sound source, how they do this remains largely unknown. In this study, we measured the potential monaural sound localization cues (head-related transfer functions; HRTFs) on alive animals and skulls in two situations, both mimicking natural positions: basking on the land and cruising at the interface between air and water. Binaural cues were also estimated by measuring the interaural level differences (ILDs) and the interaural time differences (ITDs). In both conditions, HRTF measurements show large spectral variations (greater than 10 dB) for high frequencies, depending on the azimuthal angle. These localization cues are influenced by head size and by the internal coupling of the ears. ITDs give reliable information regarding sound-source position for low frequencies, while ILDs are more suitable for frequencies higher than 1.5 kHz. Our results support the hypothesis that crocodilian head morphology is adapted to acquire reliable localization cues from sound sources when outside the water, but also when only a small part of their head is above the air–water interface.

scholarly journals Short-term effects of sound localization training in virtual reality

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mark A. Steadman ◽  
Chungeun Kim ◽  
Jean-Hugues Lestang ◽  
Dan F. M. Goodman ◽  
Lorenzo Picinali
Keyword(s):  
Sound Localization ◽  
Sound Source ◽  
Game Design ◽  
Transfer Functions ◽  
Polar Angle ◽  
Active Listening ◽  
Head Tracking ◽  
Localization Accuracy ◽  
Design Elements ◽  
Listening Group

AbstractHead-related transfer functions (HRTFs) capture the direction-dependant way that sound interacts with the head and torso. In virtual audio systems, which aim to emulate these effects, non-individualized, generic HRTFs are typically used leading to an inaccurate perception of virtual sound location. Training has the potential to exploit the brain’s ability to adapt to these unfamiliar cues. In this study, three virtual sound localization training paradigms were evaluated; one provided simple visual positional confirmation of sound source location, a second introduced game design elements (“gamification”) and a final version additionally utilized head-tracking to provide listeners with experience of relative sound source motion (“active listening”). The results demonstrate a significant effect of training after a small number of short (12-minute) training sessions, which is retained across multiple days. Gamification alone had no significant effect on the efficacy of the training, but active listening resulted in a significantly greater improvements in localization accuracy. In general, improvements in virtual sound localization following training generalized to a second set of non-individualized HRTFs, although some HRTF-specific changes were observed in polar angle judgement for the active listening group. The implications of this on the putative mechanisms of the adaptation process are discussed.

scholarly journals Sound Localization for Ad-Hoc Microphone Arrays

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3446
Author(s):  
Muhammad Usman Liaquat ◽  
Hafiz Suliman Munawar ◽  
Amna Rahman ◽  
Zakria Qadir ◽  
Abbas Z. Kouzani ◽  
...  
Keyword(s):  
Sound Localization ◽  
Sound Source ◽  
Ad Hoc ◽  
Dimensional Space ◽  
Computation Time ◽  
Location Estimation ◽  
Microphone Arrays ◽  
Sound Signal ◽  
Experimental Arrangement ◽  
Advantages And Disadvantages

Sound localization is a field of signal processing that deals with identifying the origin of a detected sound signal. This involves determining the direction and distance of the source of the sound. Some useful applications of this phenomenon exists in speech enhancement, communication, radars and in the medical field as well. The experimental arrangement requires the use of microphone arrays which record the sound signal. Some methods involve using ad-hoc arrays of microphones because of their demonstrated advantages over other arrays. In this research project, the existing sound localization methods have been explored to analyze the advantages and disadvantages of each method. A novel sound localization routine has been formulated which uses both the direction of arrival (DOA) of the sound signal along with the location estimation in three-dimensional space to precisely locate a sound source. The experimental arrangement consists of four microphones and a single sound source. Previously, sound source has been localized using six or more microphones. The precision of sound localization has been demonstrated to increase with the use of more microphones. In this research, however, we minimized the use of microphones to reduce the complexity of the algorithm and the computation time as well. The method results in novelty in the field of sound source localization by using less resources and providing results that are at par with the more complex methods requiring more microphones and additional tools to locate the sound source. The average accuracy of the system is found to be 96.77% with an error factor of 3.8%.

Subjective evaluation of the combining effect between the virtual bass and head related transfer functions

2021 ◽  
Vol 263 (5) ◽  
pp. 1488-1496
Author(s):  
Yunqi Chen ◽  
Chuang Shi ◽  
Hao Mu
Keyword(s):  
Fundamental Frequency ◽  
Sound Source ◽  
Transfer Functions ◽  
Subjective Evaluation ◽  
Low Frequency ◽  
Localization Accuracy ◽  
Frequency Sound ◽  
Listening Tests ◽  
Listening Experience ◽  
Missing Fundamental

Earphones are commonly equipped with miniature loudspeaker units, which cannot transmit enough power of low-frequency sound. Meanwhile, there is often only one loudspeaker unit employed on each side of the earphone, whereby the multi-channel spatial audio processing cannot be applied. Therefore, the combined usage of the virtual bass (VB) and head-related transfer functions (HRTFs) is necessary for an immersive listening experience with earphones. However, the combining effect of the VB and HRTFs has not been comprehensively reported. The VB is developed based on the missing fundamental effect, providing that the presence of harmonics can be perceived as their fundamental frequency, even if the fundamental frequency is not presented. HRTFs describe the transmission process of a sound propagating from the sound source to human ears. Monaural audio processed by a pair of HRTFs can be perceived by the listener as a sound source located in the direction associated with the HRTFs. This paper carries out subjective listening tests and their results reveal that the harmonics required by the VB should be generated in the same direction as the high-frequency sound. The bass quality is rarely distorted by the presence of HRTFs, but the localization accuracy is occasionally degraded by the VB.

Interdependence of Spatial and Temporal Coding in the Auditory Midbrain

2000 ◽  
Vol 83 (4) ◽  
pp. 2300-2314 ◽  
Author(s):  
U. Koch ◽  
B. Grothe
Keyword(s):  
Sound Localization ◽  
Feature Detection ◽  
Transfer Functions ◽  
Temporal Structure ◽  
Temporal Coding ◽  
Sound Recognition ◽  
Spatial Cues ◽  
Auditory Midbrain ◽  
Binaural Cues ◽  
Binaural Processing

To date, most physiological studies that investigated binaural auditory processing have addressed the topic rather exclusively in the context of sound localization. However, there is strong psychophysical evidence that binaural processing serves more than only sound localization. This raises the question of how binaural processing of spatial cues interacts with cues important for feature detection. The temporal structure of a sound is one such feature important for sound recognition. As a first approach, we investigated the influence of binaural cues on temporal processing in the mammalian auditory system. Here, we present evidence that binaural cues, namely interaural intensity differences (IIDs), have profound effects on filter properties for stimulus periodicity of auditory midbrain neurons in the echolocating big brown bat, Eptesicus fuscus. Our data indicate that these effects are partially due to changes in strength and timing of binaural inhibitory inputs. We measured filter characteristics for the periodicity (modulation frequency) of sinusoidally frequency modulated sounds (SFM) under different binaural conditions. As criteria, we used 50% filter cutoff frequencies of modulation transfer functions based on discharge rate as well as synchronicity of discharge to the sound envelope. The binaural conditions were contralateral stimulation only, equal stimulation at both ears (IID = 0 dB), and more intense at the ipsilateral ear (IID = −20, −30 dB). In 32% of neurons, the range of modulation frequencies the neurons responded to changed considerably comparing monaural and binaural (IID =0) stimulation. Moreover, in ∼50% of neurons the range of modulation frequencies was narrower when the ipsilateral ear was favored (IID = −20) compared with equal stimulation at both ears (IID = 0). In ∼10% of the neurons synchronization differed when comparing different binaural cues. Blockade of the GABAergic or glycinergic inputs to the cells recorded from revealed that inhibitory inputs were at least partially responsible for the observed changes in SFM filtering. In 25% of the neurons, drug application abolished those changes. Experiments using electronically introduced interaural time differences showed that the strength of ipsilaterally evoked inhibition increased with increasing modulation frequencies in one third of the cells tested. Thus glycinergic and GABAergic inhibition is at least one source responsible for the observed interdependence of temporal structure of a sound and spatial cues.

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