Article
Audiology & Speech-Language Pathology
Alexander C. Thompson, Dexter R. F. Irvine, James B. Fallon
Summary: Custom ITD-aware sound processing strategies can enhance ITD sensitivity in the clinical population, as shown by studies using a cat model of neonatal deafness.
Article
Neurosciences
Woongsang Sunwoo
Summary: This study examined the effect of neonatal deafness on the processing of interaural time differences (ITDs) in cochlear-implant stimuli. Animal studies have shown differences in neural ITD sensitivity based on the intracochlear location of stimulating electrodes. The results suggest that neonatal deafness significantly impacts ITD sensitivity and tuning patterns in the inferior colliculus.
Article
Audiology & Speech-Language Pathology
Kongyan Li, Vani G. Rajendran, Ambika Prasad Mishra, Chloe H. K. Chan, Jan W. H. Schnupp
Summary: The study found that neural d' values show similar trends with behavioral performance under different conditions, and neural d' correlates better with behavioral performance compared to mutual information (MI). Additionally, when ITD values are encoded as left or right ear leading, results from neural d' and MI are highly correlated.
Article
Audiology & Speech-Language Pathology
Zeeshan Haqqee, Roberto Valdizon-Rodriguez, Paul A. Faure
Summary: The study investigates the response properties of single neurons in the inferior colliculus of big brown bats to onset ITDs in high frequency pure tones. It found that neurons show sensitivity to onset ITD cues, with an average change of 36% of its maximal response within a behaviorally relevant range of ITDs. Additionally, there is a consistent average time-intensity trading ratio of 30 mu s/dB in the sensitivity of the ITD response function to changing ILDs, indicating the potential use of onset ITD cues for azimuthal sound localization in echolocating bats.
Article
Neurosciences
Jennifer L. Thornton, Kelsey L. Anbuhl, Daniel J. Tollin
Summary: Temporary conductive hearing loss can alter the response of auditory midbrain neurons to interaural level difference (ILD) cues, potentially due to compensatory plasticity occurring at least at the level of the inferior colliculus (ICC). This alteration leads to a higher proportion of monaural responsive neurons and a decreased information about ILDs in ICC neurons after the CHL. Cochlear peripheral responses were not affected by the CHL, indicating that the changes observed were centrally mediated.
FRONTIERS IN NEUROSCIENCE
(2021)
Article
Otorhinolaryngology
Monika Koertje, Timo Stoever, Uwe Baumann, Tobias Weissgerber
Summary: This study investigated the impact of interaural delay on sensitivity to interaural level differences (ILDs) in normal hearing subjects and cochlear implant (CI) users. ILD sensitivity was measured in both groups using different interaural delays induced by hearing devices. The results showed that ILD sensitivity significantly decreased with increasing interaural delays in the normal hearing group, but no significant effect was found in the CI group. Further studies are needed to verify the potential benefits of temporal matching for ILD processing and sound localization in CI patients.
EUROPEAN ARCHIVES OF OTO-RHINO-LARYNGOLOGY
(2023)
Article
Neurosciences
Woongsang Sunwoo, Seung-Ha Oh
Summary: The study examined the sensitivity of neurons in the inferior colliculus to interaural time differences conveyed in electrical pulse trains in male and female rats. Most neurons were sensitive to ITDs of electrical stimulation regardless of cochlear stimulating location. However, the pulse rate dependence of neural ITD sensitivity differed significantly depending on the location of the stimulation, with differences in ITD discrimination thresholds and tuning type between apical and basal stimulation.
JOURNAL OF NEUROSCIENCE RESEARCH
(2022)
Article
Audiology & Speech-Language Pathology
Carol A. Sammeth, Andrew D. Brown, Nathaniel T. Greene, Daniel J. Tollin
Summary: The binaural interaction component (BIC) of the auditory brainstem response (ABR) is a biomarker of binaural processing abilities. This study examined the effect of interaural frequency mismatch (IFM) on BIC and behavioral interaural time difference (ITD) sensitivity in normal adult human subjects. Results showed that IFM had significant effects on BIC amplitudes and elevated ITD discrimination thresholds. The study also found that combinations of ITD, IFM, and sound level were bound by the empirically-measured BIC.
Article
Audiology & Speech-Language Pathology
Hannah E. Staisloff, Justin M. Aronoff
Summary: This study investigated the optimal electrode pairings for bilateral cochlear implants (CIs) among seven users, finding systematic differences in pairing based on the cue measured, particularly at the basal end of the electrode array. The results suggest that improvements in binaural tasks using optimally paired electrodes may be tied to the specific percept being measured.
Article
Biology
Ya-tang Li, Markus Meister
Summary: The superior colliculus in the brain is a crucial visual processing station that receives input from various types of retinal ganglion cells. Through recording mouse superficial SC neurons, we identified 24 functional types using an unsupervised clustering algorithm. These types can be grouped into two categories: one that responds similarly to retinal ganglion cells and another with more diverse and specialized stimulus selectivity. Cells of the same functional type tend to cluster together in anatomical space, and the visual representation in the SC has lower dimensionality compared to the retina, suggesting a sifting process along the visual pathway.
Article
Biology
Bianca Krumm, Georg M. Klump, Christine Koeppl, Rainer Beutelmann, Ulrike Langemann
Summary: The study investigates the mechanisms of sound localization in chickens, showing their reliance on different cues at different frequencies. Chickens are likely to use interaural time difference cues at low frequencies and interaural level differences cues at high frequencies for sound localization.
JOURNAL OF EXPERIMENTAL BIOLOGY
(2022)
Article
Psychology, Multidisciplinary
Alexandra Annemarie Ludwig, Sylvia Meuret, Rolf-Dieter Battmer, Marc Schoenwiesner, Michael Fuchs, Arne Ernst
Summary: Spatial hearing is crucial in real life but deteriorates in participants with severe sensorineural hearing loss or single-sided deafness. This study investigated sound localization ability in participants with single-sided deafness using a unilateral cochlear implant (CI). Results showed that CI can largely restore sound localization ability in participants, with some difficulties remaining at frontal locations and on the CI side. Improved speech understanding in noise was observed with CI, particularly when sound localization was also enhanced.
FRONTIERS IN PSYCHOLOGY
(2021)
Article
Audiology & Speech-Language Pathology
Alexa N. Buck, Nicole Rosskothen-Kuhl, Jan W. H. Schnupp
Summary: This study characterized ITD sensitivity and tuning of inferior colliculus neurons under bilateral CI stimulation of neonatally deafened and hearing experienced rats. The research found that while both groups showed similar levels of ITD sensitivity, there were evident differences in tuning curve shapes, with auditory experience influencing the shapes. Despite profound hearing loss, rats demonstrated highly precise innate ITD sensitivity, suggesting that lateralization encoding is present even without auditory experience.
Article
Acoustics
Nobuhiko Hiruma, Yuto Ueda, Yuuki Yuno, Hidetoshi Nakashima
Summary: This paper proposes a correlation control method for linear prediction filters based on howling detection using binaural information in hearing aids. The proposed method improves convergence by detecting howling based on interaural level difference and controlling the decorrelation performance of the adaptive lattice filter's correlation control algorithm. Experimental results demonstrate that the proposed method significantly enhances estimation accuracy and tracking performance, as well as improves robustness to entrainment compared to traditional bilateral AFC methods.
Article
Audiology & Speech-Language Pathology
Peter Heil, Bjorn Friedrich
Summary: This study investigated different definitions of thresholds and found that thresholds defined as the logarithm of the Weber fraction for stimulus amplitude were the most suitable. It was suggested that these thresholds should be averaged arithmetically across listeners.