16,779 research outputs found

    Bone conductive implants in single sided deafness

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    Conclusion: The Bone Conductive Implants (BCI) showed to partly restore some of the functions lost when the binaural hearing is missing, such as in the single-sided deafness (SSD) subjects. The adoption of the single BCI needs to be advised by the clinician on the ground of a thorough counselling with the SSD subject. Objectives: To perform an overview of the present possibilities of BCI in SSD and to evaluate the reliability of the audiological evaluation for assessing the speech recognition in noise and the sound localization cues, as major problems related to the loss of binaural hearing. Method: Nine SSD subjects who underwent BCI implantation underwent a pre-operative audiological evaluation, consisting in the soundfield speech audiometry, as word recognition score (WRS) and sound localization, in quiet and in noise. Moreover, they were also tested for the accuracy of directional word recognition in noise and with the subjective evaluation with APHAB questionnaire. Results: The mean maximum percentage of word discrimination was 65.5% in the unaided condition and 78.9% in the BCI condition. The sound localization in noise with the BCI was better than the unaided condition, especially when stimulus and noise were on the same side of the implanted ear. The accuracy of directional word recognition showed to improve with BCI in respect to the unaided condition, in the BCI side, with either the stimulus on the implanted ear and the noise in the contralateral ear, or when both stimulus and noise were deliver to implanted ear

    Bilateral cochlear implantation or bimodal listening in the paediatric population : retrospective analysis of decisive criteria

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    Introduction: In children with bilateral severe to profound hearing loss, bilateral hearing can be achieved by either bimodal stimulation (CIHA) or bilateral cochlear implantation (BICI). The aim of this study was to analyse the audiologic test protocol that is currently applied to make decisions regarding the bilateral hearing modality in the paediatric population. Methods: Pre- and postoperative audiologic test results of 21 CIHA, 19 sequential BICI and 12 simultaneous BICI children were examined retrospectively. Results: Deciding between either simultaneous BICI or unilateral implantation was mainly based on the infant's preoperative Auditory Brainstem Response thresholds. Evolution from CIHA to sequential BICI was mainly based on the audiometric test results in the contralateral (hearing aid) ear after unilateral cochlear implantation. Preoperative audiometric thresholds in the hearing aid ear were significantly better in CIHA versus sequential BICI children (p < 0.001 and p = 0.001 in unaided and aided condition, respectively). Decisive values obtained in the hearing aid ear in favour of BICI were: An average hearing threshold measured at 0.5, 1, 2 and 4 kHz of at least 93 dB HL without, and at least 52 dB HL with hearing aid together with a 40% aided speech recognition score and a 70% aided score on the phoneme discrimination subtest of the Auditory Speech Sounds Evaluation test battery. Conclusions: Although pure tone audiometry offers no information about bimodal benefit, it remains the most obvious audiometric evaluation in the decision process on the mode of bilateral stimulation in the paediatric population. A theoretical test protocol for adequate evaluation of bimodal benefit in the paediatric population is proposed

    An outdoor spatially-aware audio playback platform exemplified by a virtual zoo

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    Outlined in this short paper is a framework for the construction of outdoor location-and direction-aware audio applications along with an example application to showcase the strengths of the framework and to demonstrate how it works. Although there has been previous work in this area which has concentrated on the spatial presentation of sound through wireless headphones, typically such sounds are presented as though originating from specific, defined spatial locations within a 3D environment. Allowing a user to move freely within this space and adjusting the sound dynamically as we do here, further enhances the perceived reality of the virtual environment. Techniques to realise this are implemented by the real-time adjustment of the presented 2 channels of audio to the headphones, using readings of the user's head orientation and location which in turn are made possible by sensors mounted upon the headphones. Aside from proof of concept indoor applications, more user-responsive applications of spatial audio delivery have not been prototyped or explored. In this paper we present an audio-spatial presentation platform along with a primary demonstration application for an outdoor environment which we call a {\em virtual audio zoo}. This application explores our techniques to further improve the realism of the audio-spatial environments we can create, and to assess what types of future application are possible

    Software Defined Media: Virtualization of Audio-Visual Services

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    Internet-native audio-visual services are witnessing rapid development. Among these services, object-based audio-visual services are gaining importance. In 2014, we established the Software Defined Media (SDM) consortium to target new research areas and markets involving object-based digital media and Internet-by-design audio-visual environments. In this paper, we introduce the SDM architecture that virtualizes networked audio-visual services along with the development of smart buildings and smart cities using Internet of Things (IoT) devices and smart building facilities. Moreover, we design the SDM architecture as a layered architecture to promote the development of innovative applications on the basis of rapid advancements in software-defined networking (SDN). Then, we implement a prototype system based on the architecture, present the system at an exhibition, and provide it as an SDM API to application developers at hackathons. Various types of applications are developed using the API at these events. An evaluation of SDM API access shows that the prototype SDM platform effectively provides 3D audio reproducibility and interactiveness for SDM applications.Comment: IEEE International Conference on Communications (ICC2017), Paris, France, 21-25 May 201

    Effects of cochlear implantation on binaural hearing in adults with unilateral hearing loss

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    A FDA clinical trial was carried out to evaluate the potential benefit of cochlear implant (CI) use for adults with unilateral moderate-to-profound sensorineural hearing loss. Subjects were 20 adults with moderate-to-profound unilateral sensorineural hearing loss and normal or near-normal hearing on the other side. A MED-EL standard electrode was implanted in the impaired ear. Outcome measures included: (a) sound localization on the horizontal plane (11 positions, −90° to 90°), (b) word recognition in quiet with the CI alone, and (c) masked sentence recognition with the target at 0° and the masker at −90°, 0°, or 90°. This battery was completed preoperatively and at 1, 3, 6, 9, and 12 months after CI activation. Normative data were also collected for 20 age-matched control subjects with normal or near-normal hearing bilaterally. The CI improved localization accuracy and reduced side bias. Word recognition with the CI alone was similar to performance of traditional CI recipients. The CI improved masked sentence recognition when the masker was presented from the front or from the side of normal or near-normal hearing. The binaural benefits observed with the CI increased between the 1- and 3-month intervals but appeared stable thereafter. In contrast to previous reports on localization and speech perception in patients with unilateral sensorineural hearing loss, CI benefits were consistently observed across individual subjects, and performance was at asymptote by the 3-month test interval. Cochlear implant settings, consistent CI use, and short duration of deafness could play a role in this result

    Now Hear This! Orientation and Behavioral Responses of Hatchling Loggerhead Sea Turtles, Caretta caretta, to Environmental Acoustic Cues

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    Although the visual and geologic orientation cues utilized by sea turtle hatchlings during seafinding, when they move from the nest to the sea after hatching, have been well studied, the potential for auditory stimuli to act as an orientation cue has not been well explored. Over the past several decades our knowledge of the auditory capacity of sea turtles has increased greatly, yet little is known about the biological significance of this sensory ability. To investigate whether hatchlings can use ocean sounds during seafinding, we measured the behavioral responses of hatchling loggerhead sea turtles (Caretta caretta) collected from nesting beaches in North Carolina to the presence of beach wave sound recorded on a nesting beach during the summer of 2015. The highest sound energy of beach waves occursHz, which overlaps with the most sensitive hearing range of loggerhead hatchlings (range of frequency detection: 50-1600 Hz, maximum sensitivity: 50-400 Hz). In our experiment, we placed turtles in a V-maze that isolated them from visual, vibratory, and chemical cues. One end of the V held a speaker producing beach wave sounds recorded from nesting beaches, while the other end held sound-reducing foam. We examined the phonotaxic behaviors of the hatchlings at two sound pressure levels (68 dB re: 20μPa and 64 dB re: 20μPa measured directly in front of the speaker). In the presence of the higher sound pressure level (68 dB re: 20μPa), hatchlings exhibited no phonotaxic response (p=1.0); yet, at the reduced sound pressure level (64 dB re: 20μPa), hatchlings exhibited a negative phonotaxic response (p=0.005). In control trials, hatchlings oriented to the two sides of the V-maze equally (p=0.701), suggesting the hatchlings in the lower volume treatment group were responding negatively to the sound. These results indicate the need for further auditory orientation experiments to better understand hatchling behavioral responses to environmental acoustic cues and to address possible impacts of anthropogenic beach sounds that have the potential to disorient hatchlings during seafinding

    Inhibiting the inhibition

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    The precedence effect describes the phenomenon whereby echoes are spatially fused to the location of an initial sound by selectively suppressing the directional information of lagging sounds (echo suppression). Echo suppression is a prerequisite for faithful sound localization in natural environments but can break down depending on the behavioral context. To date, the neural mechanisms that suppress echo directional information without suppressing the perception of echoes themselves are not understood. We performed in vivo recordings in Mongolian gerbils of neurons of the dorsal nucleus of the lateral lemniscus (DNLL), a GABAergic brainstem nucleus that targets the auditory midbrain, and show that these DNLL neurons exhibit inhibition that persists tens of milliseconds beyond the stimulus offset, so-called persistent inhibition (PI). Using in vitro recordings, we demonstrate that PI stems from GABAergic projections from the opposite DNLL. Furthermore, these recordings show that PI is attributable to intrinsic features of this GABAergic innervation. Implementation of these physiological findings into a neuronal model of the auditory brainstem demonstrates that, on a circuit level, PI creates an enhancement of responsiveness to lagging sounds in auditory midbrain cells. Moreover, the model revealed that such response enhancement is a sufficient cue for an ideal observer to identify echoes and to exhibit echo suppression, which agrees closely with the percepts of human subjects

    "Sitting too close to the screen can be bad for your ears": A study of audio-visual location discrepancy detection under different visual projections

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    In this work, we look at the perception of event locality under conditions of disparate audio and visual cues. We address an aspect of the so called “ventriloquism effect” relevant for multi-media designers; namely, how auditory perception of event locality is influenced by the size and scale of the accompanying visual projection of those events. We observed that recalibration of the visual axes of an audio-visual animation (by resizing and zooming) exerts a recalibrating influence on the auditory space perception. In particular, sensitivity to audio-visual discrepancies (between a centrally located visual stimuli and laterally displaced audio cue) increases near the edge of the screen on which the visual cue is displayed. In other words,discrepancy detection thresholds are not fixed for a particular pair of stimuli, but are influenced by the size of the display space. Moreover, the discrepancy thresholds are influenced by scale as well as size. That is, the boundary of auditory space perception is not rigidly fixed on the boundaries of the screen; it also depends on the spatial relationship depicted. For example,the ventriloquism effect will break down within the boundaries of a large screen if zooming is used to exaggerate the proximity of the audience to the events. The latter effect appears to be much weaker than the former

    Localization and Rendering of Sound Sources in Acoustic Fields

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    Disertační práce se zabývá lokalizací zdrojů zvuku a akustickým zoomem. Hlavním cílem této práce je navrhnout systém s akustickým zoomem, který přiblíží zvuk jednoho mluvčího mezi skupinou mluvčích, a to i když mluví současně. Tento systém je kompatibilní s technikou prostorového zvuku. Hlavní přínosy disertační práce jsou následující: 1. Návrh metody pro odhad více směrů přicházejícího zvuku. 2. Návrh metody pro akustické zoomování pomocí DirAC. 3. Návrh kombinovaného systému pomocí předchozích kroků, který může být použit v telekonferencích.This doctoral thesis deals with sound source localization and acoustic zooming. The primary goal of this dissertation is to design an acoustic zooming system, which can zoom the sound of one speaker among multiple speakers even when they speak simultaneously. The system is compatible with surround sound techniques. In particular, the main contributions of the doctoral thesis are as follows: 1. Design of a method for multiple sound directions estimations. 2. Proposing a method for acoustic zooming using DirAC. 3. Design a combined system using the previous mentioned steps, which can be used in teleconferencing.

    A comparison of feedback cues for enhancing pointing efficiency in interaction with spatial audio displays

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    An empirical study that compared six different feedback cue types to enhance pointing efficiency in deictic spatial audio displays is presented. Participants were asked to select a sound using a physical pointing gesture, with the help of a loudness cue, a timbre cue and an orientation update cue as well as with combinations of these cues. Display content was varied systematically to investigate the effect of increasing display population. Speed, accuracy and throughput ratings are provided as well as effective target widths that allow for minimal error rates. The results showed direct pointing to be the most efficient interaction technique; however large effective target widths reduce the applicability of this technique. Movement-coupled cues were found to significantly reduce display element size, but resulted in slower interaction and were affected by display content due to the requirement of continuous target attainment. The results show that, with appropriate design, it is possible to overcome interaction uncertainty and provide solutions that are effective in mobile human computer interaction
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