Sound Localization in Single-Sided Deaf Participants Provided With a Cochlear Implant

Spatial hearing is crucial in real life but deteriorates in participants with severe sensorineural hearing loss or single-sided deafness. This ability can potentially be improved with a unilateral cochlear implant (CI). The present study investigated measures of sound localization in participants with single-sided deafness provided with a CI. Sound localization was measured separately at eight loudspeaker positions (4°, 30°, 60°, and 90°) on the CI side and on the normal-hearing side. Low- and high-frequency noise bursts were used in the tests to investigate possible differences in the processing of interaural time and level differences. Data were compared to normal-hearing adults aged between 20 and 83. In addition, the benefit of the CI in speech understanding in noise was compared to the localization ability. Fifteen out of 18 participants were able to localize signals on the CI side and on the normal-hearing side, although performance was highly variable across participants. Three participants always pointed to the normal-hearing side, irrespective of the location of the signal. The comparison with control data showed that participants had particular difficulties localizing sounds at frontal locations and on the CI side. In contrast to most previous results, participants were able to localize low-frequency signals, although they localized high-frequency signals more accurately. Speech understanding in noise was better with the CI compared to testing without CI, but only at a position where the CI also improved sound localization. Our data suggest that a CI can, to a large extent, restore localization in participants with single-sided deafness. Difficulties may remain at frontal locations and on the CI side. However, speech understanding in noise improves when wearing the CI. The treatment with a CI in these participants might provide real-world benefits, such as improved orientation in traffic and speech understanding in difficult listening situations.

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Bimodal Cochlear Implant Listeners’ Ability to Perceive Minimal Audible Angle Differences

Journal of the American Academy of Audiology ◽

10.3766/jaaa.17012 ◽

2019 ◽

Vol 30 (08) ◽

pp. 659-671 ◽

Cited By ~ 1

Author(s):

Ashley Zaleski-King ◽

Matthew J. Goupell ◽

Dragana Barac-Cikoja ◽

Matthew Bakke

Keyword(s):

Cochlear Implant ◽

Sound Localization ◽

Repeated Measures ◽

Free Field ◽

Low Frequency ◽

Spatial Location ◽

Speech Understanding ◽

Repeated Measures Design ◽

Acoustic Environments ◽

The Right

AbstractBilateral inputs should ideally improve sound localization and speech understanding in noise. However, for many bimodal listeners [i.e., individuals using a cochlear implant (CI) with a contralateral hearing aid (HA)], such bilateral benefits are at best, inconsistent. The degree to which clinically available HA and CI devices can function together to preserve interaural time and level differences (ITDs and ILDs, respectively) enough to support the localization of sound sources is a question with important ramifications for speech understanding in complex acoustic environments.To determine if bimodal listeners are sensitive to changes in spatial location in a minimum audible angle (MAA) task.Repeated-measures design.Seven adult bimodal CI users (28–62 years). All listeners reported regular use of digital HA technology in the nonimplanted ear.Seven bimodal listeners were asked to balance the loudness of prerecorded single syllable utterances. The loudness-balanced stimuli were then presented via direct audio inputs of the two devices with an ITD applied. The task of the listener was to determine the perceived difference in processing delay (the interdevice delay [IDD]) between the CI and HA devices. Finally, virtual free-field MAA performance was measured for different spatial locations both with and without inclusion of the IDD correction, which was added with the intent to perceptually synchronize the devices.During the loudness-balancing task, all listeners required increased acoustic input to the HA relative to the CI most comfortable level to achieve equal interaural loudness. During the ITD task, three listeners could perceive changes in intracranial position by distinguishing sounds coming from the left or from the right hemifield; when the CI was delayed by 0.73, 0.67, or 1.7 msec, the signal lateralized from one side to the other. When MAA localization performance was assessed, only three of the seven listeners consistently achieved above-chance performance, even when an IDD correction was included. It is not clear whether the listeners who were able to consistently complete the MAA task did so via binaural comparison or by extracting monaural loudness cues. Four listeners could not perform the MAA task, even though they could have used a monaural loudness cue strategy.These data suggest that sound localization is extremely difficult for most bimodal listeners. This difficulty does not seem to be caused by large loudness imbalances and IDDs. Sound localization is best when performed via a binaural comparison, where frequency-matched inputs convey ITD and ILD information. Although low-frequency acoustic amplification with a HA when combined with a CI may produce an overlapping region of frequency-matched inputs and thus provide an opportunity for binaural comparisons for some bimodal listeners, our study showed that this may not be beneficial or useful for spatial location discrimination tasks. The inability of our listeners to use monaural-level cues to perform the MAA task highlights the difficulty of using a HA and CI together to glean information on the direction of a sound source.

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Interaural Level Difference Cues Determine Sound Source Localization by Single-Sided Deaf Patients Fit with a Cochlear Implant

Audiology and Neurotology ◽

10.1159/000375394 ◽

2015 ◽

Vol 20 (3) ◽

pp. 183-188 ◽

Cited By ~ 27

Author(s):

Michael F. Dorman ◽

Daniel Zeitler ◽

Sarah J. Cook ◽

Louise Loiselle ◽

William A. Yost ◽

...

Keyword(s):

Cochlear Implant ◽

Source Localization ◽

Sound Source ◽

Low Frequency ◽

Normal Hearing ◽

Sound Source Localization ◽

Interaural Level Difference ◽

Relative Localization ◽

Normal Limits ◽

Single Sided Deafness

In this report, we used filtered noise bands to constrain listeners' access to interaural level differences (ILDs) and interaural time differences (ITDs) in a sound source localization task. The samples of interest were listeners with single-sided deafness (SSD) who had been fit with a cochlear implant in the deafened ear (SSD-CI). The comparison samples included listeners with normal hearing and bimodal hearing, i.e. with a cochlear implant in 1 ear and low-frequency acoustic hearing in the other ear. The results indicated that (i) sound source localization was better in the SSD-CI condition than in the SSD condition, (ii) SSD-CI patients rely on ILD cues for sound source localization, (iii) SSD-CI patients show functional localization abilities within 1-3 months after device activation and (iv) SSD-CI patients show better sound source localization than bimodal CI patients but, on average, poorer localization than normal-hearing listeners. One SSD-CI patient showed a level of localization within normal limits. We provide an account for the relative localization abilities of the groups by reference to the differences in access to ILD cues.

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Cochlear Implant: Effect of the Number of Channel and Frequency Selectivity on Speech Understanding in Noise Preliminary Results in Simulation with Normal-Hearing Subjects

Modelling Measurement and Control C ◽

10.18280/mmc_c.811-404 ◽

2020 ◽

Vol 81 (1-4) ◽

pp. 17-23

Author(s):

P.A. Cucis ◽

C. Berger-Vachon ◽

R. Hermann ◽

H. Thaï-Van ◽

S. Gallego ◽

...

Keyword(s):

Cochlear Implant ◽

Signal To Noise Ratio ◽

Normal Hearing ◽

Measuring Channel ◽

Frequency Selectivity ◽

Speech Understanding ◽

Preliminary Results ◽

Channel Interaction ◽

Speech Understanding In Noise ◽

The Impact

The cochlear implant is the most successful implantable device for the rehabilitation of profound deafness. However, in some cases, the electrical stimulation delivered by the electrode can spread inside the cochlea creating overlap and interaction between frequency channels. By using channel-selection algorithms like the “nofm” coding-strategy, channel interaction can be reduced. This paper describes the preliminary results of experiments conducted with normal hearing subjects (n = 9). Using a vocoder, the present study simulated the hearing through a cochlear implant. Speech understanding in noise was measured by varying the number of selected channels (“nofm”: 4, 8, 12 and 16of20) and the degree of simulated channel interaction (“Low”, “Medium”, “High”). Also, with the vocoder, we evaluated the impact of simulated channel interaction on frequency selectivity by measuring psychoacoustic tuning curves. The results showed a significant average effect of the signal-to-noise ratio (p < 0.0001), the degree of channel interaction (p < 0.0001) and the number of selected channels, (p = 0.029). The highest degree of channel interaction significantly decreases intelligibility as well as frequency selectivity. These results underline the importance of measuring channel interaction for cochlear implanted patients to have a prognostic test and to adjust fitting methods in consequence. The next step of this project will be to transpose these experiments to implant users, to support our results.

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Head Shadow, Summation, and Squelch in Bilateral Cochlear-Implant Users With Linked Automatic Gain Controls

Trends in Hearing ◽

10.1177/23312165211018147 ◽

2021 ◽

Vol 25 ◽

pp. 233121652110181

Author(s):

Taylor A. Bakal ◽

Kristina DeRoy Milvae ◽

Chen Chen ◽

Matthew J. Goupell

Keyword(s):

Cochlear Implant ◽

Functional Performance ◽

Binaural Hearing ◽

Normal Hearing ◽

Functional Asymmetry ◽

Speech Understanding ◽

Speech Understanding In Noise ◽

Bilateral Cochlear Implant ◽

Automatic Gain Controls ◽

Interaural Level Differences

Speech understanding in noise is poorer in bilateral cochlear-implant (BICI) users compared to normal-hearing counterparts. Independent automatic gain controls (AGCs) may contribute to this because adjusting processor gain independently can reduce interaural level differences that BICI listeners rely on for bilateral benefits. Bilaterally linked AGCs may improve bilateral benefits by increasing the magnitude of interaural level differences. The effects of linked AGCs on bilateral benefits (summation, head shadow, and squelch) were measured in nine BICI users. Speech understanding for a target talker at 0° masked by a single talker at 0°, 90°, or −90° azimuth was assessed under headphones with sentences at five target-to-masker ratios. Research processors were used to manipulate AGC type (independent or linked) and test ear (left, right, or both). Sentence recall was measured in quiet to quantify individual interaural asymmetry in functional performance. The results showed that AGC type did not significantly change performance or bilateral benefits. Interaural functional asymmetries, however, interacted with ear such that greater summation and squelch benefit occurred when there was larger functional asymmetry, and interacted with interferer location such that smaller head shadow benefit occurred when there was larger functional asymmetry. The larger benefits for those with larger asymmetry were driven by improvements from adding a better-performing ear, rather than a true binaural-hearing benefit. In summary, linked AGCs did not significantly change bilateral benefits in cases of speech-on-speech masking with a single-talker masker, but there was also no strong detriment across a range of target-to-masker ratios, within a small and diverse BICI listener population.

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Benefits of Binaural Integration in Cochlear Implant Patients with Single-Sided Deafness and Residual Hearing in the Implanted Ear

Life ◽

10.3390/life11030265 ◽

2021 ◽

Vol 11 (3) ◽

pp. 265

Author(s):

Artur Lorens ◽

Anita Obrycka ◽

Piotr Henryk Skarzynski ◽

Henryk Skarzynski

Keyword(s):

Cochlear Implant ◽

Sound Localization ◽

Low Frequency ◽

Hearing Preservation ◽

Residual Hearing ◽

Low Frequencies ◽

Monosyllabic Words ◽

Localization Ability ◽

Single Sided Deafness ◽

Spatial Locations

The purpose of the study is to gauge the benefits of binaural integration effects (redundancy and squelch) due to preserved low-frequency residual hearing in the implanted ear of cochlear implant users with single-sided deafness. There were 11 cochlear implant users (age 18–61 years old) who had preserved low-frequency hearing in the implanted ear; they had a normal hearing or mild hearing loss in the contralateral ear. Patients were tested with monosyllabic words, under different spatial locations of speech and noise and with the cochlear implant activated and deactivated, in two listening configurations—one in which low frequencies in the implanted ear were masked and another in which they were unmasked. We also investigated how cochlear implant benefit due to binaural integration depended on unaided sound localization ability. Patients benefited from the binaural integration effects of redundancy and squelch only in the unmasked condition. Pearson correlations between binaural integration effects and unaided sound localization error showed significance only for squelch (r = −0.67; p = 0.02). Hearing preservation after cochlear implantation has considerable benefits because the preserved low-frequency hearing in the implanted ear contributes to binaural integration, presumably through the preserved temporal fine structure.

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Reducing interaural tonotopic mismatch preserves binaural unmasking in cochlear implant simulations of single-sided deafness

10.1101/2020.12.07.414813 ◽

2020 ◽

Author(s):

Elad Sagi ◽

Mahan Azadpour ◽

Jonathan Neukam ◽

Nicole Hope Capach ◽

Mario A. Svirsky

Keyword(s):

Cochlear Implant ◽

Low Frequency ◽

Spatial Separation ◽

Binaural Hearing ◽

Normal Hearing ◽

Input Frequency ◽

Frequency Range ◽

Speech Processor ◽

Frequency Information ◽

Single Sided Deafness

Binaural unmasking, a key feature of normal binaural hearing, refers to the improved intelligibility of masked speech by adding masking noise that facilities perceived spatial separation of target and masker. A question particularly relevant for cochlear implant users with single-sided deafness (SSD-CI) is whether binaural unmasking can still be achieved if the additional masking is distorted. Adding the CI restores some aspects of binaural hearing to these listeners, although binaural unmasking remains limited. Notably, these listeners may experience a mismatch between the frequency information perceived through the CI and that perceived by their normal hearing ear. Employing acoustic simulations of SSD-CI with normal hearing listeners, the present study confirms a previous simulation study that binaural unmasking is severely limited when interaural frequency mismatch between the input frequency range and simulated place of stimulation exceeds 1-2 mm. The present study also shows that binaural unmasking is largely retained when the input frequency range is adjusted to match simulated place of stimulation, even at the expense of removing low-frequency information. This result bears implication for the mechanisms driving the type of binaural unmasking of the present study, as well as for mapping the frequency range of the CI speech processor in SSD-CI users.

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Tunable characteristics of low-frequency bandgaps in two-dimensional multivibrator phononic crystal plates under prestrain

Scientific Reports ◽

10.1038/s41598-021-87904-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hai-Fei Zhu ◽

Xiao-Wei Sun ◽

Ting Song ◽

Xiao-Dong Wen ◽

Xi-Xuan Liu ◽

...

Keyword(s):

Phononic Crystal ◽

Real Life ◽

Low Frequency ◽

Acoustic Vibration ◽

Crystal Plate ◽

Frequency Noise ◽

Two Dimensional ◽

The Matrix ◽

Noise Frequency ◽

Realtime Control

AbstractIn view of the influence of variability of low-frequency noise frequency on noise prevention in real life, we present a novel two-dimensional tunable phononic crystal plate which is consisted of lead columns deposited in a silicone rubber plate with periodic holes and calculate its bandgap characteristics by finite element method. The low-frequency bandgap mechanism of the designed model is discussed simultaneously. Accordingly, the influence of geometric parameters of the phononic crystal plate on the bandgap characteristics is analyzed and the bandgap adjustability under prestretch strain is further studied. Results show that the new designed phononic crystal plate has lower bandgap starting frequency and wider bandwidth than the traditional single-sided structure, which is due to the coupling between the resonance mode of the scatterer and the long traveling wave in the matrix with the introduction of periodic holes. Applying prestretch strain to the matrix can realize active realtime control of low-frequency bandgap under slight deformation and broaden the low-frequency bandgap, which can be explained as the multiple bands tend to be flattened due to the localization degree of unit cell vibration increases with the rise of prestrain. The presented structure improves the realtime adjustability of sound isolation and vibration reduction frequency for phononic crystal in complex acoustic vibration environments.

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Aerodynamic noise from an asymmetric airfoil with perforated extension plates at the trailing edge

International Journal of Aeroacoustics ◽

10.1177/1475472x20978388 ◽

2020 ◽

pp. 1475472X2097838

Author(s):

CK Sumesh ◽

TJS Jothi

Keyword(s):

High Frequency ◽

Sound Pressure ◽

Pore Diameter ◽

Low Frequency ◽

Aerodynamic Noise ◽

Frequency Noise ◽

Low Frequency Noise ◽

Trailing Edge ◽

High Frequency Noise ◽

Displacement Thickness

This paper investigates the noise emissions from NACA 6412 asymmetric airfoil with different perforated extension plates at the trailing edge. The length of the extension plate is 10 mm, and the pore diameters ( D) considered for the study are in the range of 0.689 to 1.665 mm. The experiments are carried out in the flow velocity ( U∞) range of 20 to 45 m/s, and geometric angles of attack ( αg) values of −10° to +10°. Perforated extensions have an overwhelming response in reducing the low frequency noise (<1.5 kHz), and a reduction of up to 6 dB is observed with an increase in the pore diameter. Contrastingly, the higher frequency noise (>4 kHz) is observed to increase with an increase in the pore diameter. The dominant reduction in the low frequency noise for perforated model airfoils is within the Strouhal number (based on the displacement thickness) of 0.11. The overall sound pressure levels of perforated model airfoils are observed to reduce by a maximum of 2 dB compared to the base airfoil. Finally, by varying the geometric angle of attack from −10° to +10°, the lower frequency noise is seen to increase, while the high frequency noise is observed to decrease.

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Body Sensation of Low Frequency Noise of Ordinary Persons and Profoundly Deaf Persons

Journal of Low Frequency Noise Vibration and Active Control ◽

10.1177/026309238300200302 ◽

1983 ◽

Vol 2 (3) ◽

pp. 32-36 ◽

Cited By ~ 19

Author(s):

S. Yamada ◽

M. Ikuji ◽

S. Fujikata ◽

T. Watanabe ◽

T. Kosaka

Keyword(s):

Low Frequency ◽

Semicircular Canals ◽

Normal Hearing ◽

Frequency Noise ◽

Low Frequency Noise ◽

Body Sensation ◽

Deaf Persons

Comparison of the thresholds of body sensation of profoundly deaf subjects and those of normal hearing, when exposed to intense low frequency noise, showed similar trends. Since the deaf subjects were judged to have normal balance mechanisms, it was concluded that the semicircular canals are not sensitive to low frequency noise at its normal levels in the environment.

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