In this paper, the authors introduce an algorithm for locating sound-producing fish in a small rectangular tank that can be used, e.g., in behavioral bioacoustical studies to determine which fish in a group is sound-producing. The technique consists of locating a single sound source in the tank using signals gathered by four hydrophones placed in the tank together with a group of fish under study. The localization algorithm used in this paper is based on a ratio of two spectra ratios: the spectra ratio between the sound pressure measured by hydrophones at two locations and the spectra ratio between the theoretical Green's functions at the same locations. The results are compared to a localization based on image processing technique and with video recordings acquired synchronously with the acoustic recordings.

• MeSH
• Acoustics MeSH
• Batrachoidiformes physiology   MeSH
• Sound Localization physiology   MeSH
• Motor Vehicles MeSH
• Motion MeSH
• Fishes MeSH
• Models, Theoretical MeSH
• Water * MeSH
• Vocalization, Animal physiology   MeSH
• Animals MeSH
• Sound * MeSH
• Sound Spectrography methods   MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

This paper presents a rate-code model of binaural interaction inspired by recent neurophysiological findings. The model consists of a peripheral part and a binaural part. The binaural part is composed of models of the medial superior olive (MSO) and the lateral superior olive (LSO), which are parts of the auditory brainstem. The MSO and LSO model outputs are preprocessed in the interaural time difference (ITD) and interaural level difference (ILD) central stages, respectively, which give absolute values of the predicted lateralization at their outputs, allowing a direct comparison with psychophysical data. The predictions obtained with the MSO and LSO models are compared with subjective data on the lateralization of pure tones and narrowband noises, discrimination of the ITD and ILD, and discrimination of the phase warp. The lateralization and discrimination experiments show good agreement with the subjective data. In the case of the phase-warp experiment, the models agree qualitatively with the subjective data. The results demonstrate that rate-code models of MSO and LSO can be used to explain psychophysical data considering lateralization and discrimination based on binaural cues.

• MeSH
• Discrimination, Psychological MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Sound Localization * MeSH
• Models, Neurological * MeSH
• Brain Stem physiology   MeSH
• Evoked Potentials, Auditory, Brain Stem MeSH
• Ear physiology   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

The red fox (Vulpes vulpes) is the carnivore with the widest distribution in the world. Not much is known about the visual system of these predominantly forest-dwelling animals. The closely related Arctic fox (Vulpes lagopus) lives in more open tundra habitats. In search for corresponding adaptations, we examined the photoreceptors and retinal ganglion cells (RGCs), using opsin immunohistochemistry, lucifer yellow injections and Nissl staining. Both species possess a majority of middle-to-longwave-sensitive (M/L) and a minority of shortwave-sensitive (S) cones, indicating dichromatic color vision. Area centralis peak cone densities are 22,600/mm2 in the red fox and 44,800/mm2 in the Arctic fox. Both have a centro-peripheral density decrease of M/L cones, and a dorsoventrally increasing density of S cones. Rod densities and rod/cone ratios are higher in the red fox than the Arctic fox. Both species possess the carnivore-typical alpha and beta RGCs. The RGC topography shows a centro-peripheral density gradient with a distinct area centralis (mean peak density 7,900 RGCs/mm2 in the red fox and 10,000 RGCs/mm2 in the Arctic fox), a prominent visual streak of higher RGC densities in the Arctic fox, and a moderate visual streak in the red fox. Visual acuity and estimated sound localization ability were nearly identical between both species. In summary, the red fox retina shows adaptations to nocturnal activity in a forest habitat, while the Arctic fox retina is better adapted to higher light levels in the open tundra.

• MeSH
• Retinal Cone Photoreceptor Cells physiology   MeSH
• Species Specificity MeSH
• Photoreceptor Cells, Vertebrate physiology   MeSH
• Immunohistochemistry MeSH
• Foxes physiology   MeSH
• Sound Localization physiology   MeSH
• Eye anatomy & histology   MeSH
• Opsins metabolism   MeSH
• Retinal Ganglion Cells physiology   MeSH
• Retinal Rod Photoreceptor Cells physiology   MeSH
• Color Vision physiology   MeSH
• Environment MeSH
• Visual Acuity physiology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH

Bonebridge a BAHA sú implantačné systémy kostného vedenia pre pacientov s prevodovou alebo kombinovanou poruchou sluchu a s jednostrannou hluchotou, kedy sa zvuk nedostane do vnútorného ucha prirodzenou cestou cez vonkajšie a stredné ucho. Pomocou Bonebridge a BAHA sa zvukové vlny prenesú kostným vedením priamo do vnútorného ucha na implantovanej strane, ale aj do kontralaterárneho vnútorného ucha, čo sa využíva u pacientov s jednostrannou hluchotou.

Bonebridge and BAHA are bone conduction implant systems for patients with transitional or combined hearing disorder and unilateral deafness, when the sound does not reach inner ear in a natural way through the outer and middle ear. With Bonebridge and BAHA, the sound waves are transmitted via bone conduction directly to the inner ear on the implanted side, but also to the contralateral inner ear, which is used by patients with unilateral deafness.

• MeSH
• Audiology MeSH
• Deafness MeSH
• Prosthesis Implantation methods   MeSH
• Hearing Loss, Unilateral MeSH
• Bone Conduction MeSH
• Sound Localization MeSH
• Nursing Care MeSH
• Otologic Surgical Procedures MeSH
• Otolaryngology MeSH
• Hearing Aids MeSH

Skull base tumors and, in particular, vestibular schwannoma (VS) are among the etiological reasons for single-sided deafness (SSD). Patients with SSD have problems in understanding speech in a noisy environment and cannot localize the direction of sounds. For the majority, this is the handicap for which they try to find a solution. Apart from CROS hearing aids, Baha is one of the most frequently used systems for SSD compensation. 38 patients with single-sided deafness after retrosigmoid removal of a vestibular schwannoma underwent testing with a Baha softband from September 2010 to August 2014. Sixteen patients (42 %) finally decided to accept Baha implantation. Subjective experience with the Baha softband was evaluated by patients using the BBSS questionnaire immediately after testing. Objective evaluation of the effect was performed as a measurement of the sentence discrimination score in noise and side horizontal discrimination without a Baha and 6 weeks and 12 months after a sound processor fitting. There was a significant improvement in sentence discrimination in the 6 week (64.0 %) and 1 year (74.6 %) interval of follow-up in comparison with understanding without Baha (24.0 %, p = 0.001) in situations when sentences are coming from the side of the non-hearing ear and noise contralaterally with SNR -5 dB. Baha can significantly improve sentence discrimination in complex-listening situation in patients with SSD after the VS surgery.

• MeSH
• Adult MeSH
• Hearing Loss, Unilateral etiology   surgery   MeSH
• Middle Aged MeSH
• Humans MeSH
• Sound Localization MeSH
• Prostheses and Implants * MeSH
• Aged MeSH
• Hearing Aids * MeSH
• Speech Intelligibility MeSH
• Neuroma, Acoustic complications   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

Cíl: Shrnout výsledky souboru pacientů používajících implantabilní sluchový systém Baha (Bone anchored hearing aid; Baha) využívající princip kostního vedení pro kompenzaci jednostranné hluchoty (Single-Sided Deafness; SSD), bez ohledu na etiologii, která může být vrozená, vaskulární (náhlá percepční nedoslýchavost; Sudden Sensorineural Hearing Loss; SSNHL), infekční, traumatická, nádorová nebo iatrogenní. Soubor a metodika: V období od září 2010 do srpna 2014 bylo vyšetřeno a do studie zařazeno 59 pacientů s SSD. Etiologií SSD byla náhlá percepční nedoslýchavost, fraktura pyramidy, ototoxické působení léčby, úraz ucha, chronická otitida i růst vestibulárního schwannomu. Výsledky: Všichni pacienti si vyzkoušeli efekt pomocí Baha Softbandu a 23 z nich se rozhodlo pro Baha implantaci. V průběhu studie byly použity tři generace Baha implantátů (BI300, BIA400, Attract), bez peroperačních či pooperačních komplikací. Efektivita Baha byla prokázána při testování větné srozumitelnosti v šumu, kdy v odstupu šesti týdnů i jednoho roku dochází k signifikantnímu zlepšování výsledků za situace, že signál přichází ze strany hluchého ucha a šum ze strany normálně slyšícího, na hladině hlasitosti 65 dB SPL, resp. 70 dB SPL. Závěry: Baha je efektivní možnost kompenzace pacientů s SSD a nabídnutí i vyzkoušení implantabilních a/nebo nechirurgických možností kompenzace by mělo být samozřejmou součástí péče o pacienty s jednostrannou hluchotou.

Aim: To summarize data for the Baha (Bone anchored hearing aid) implantable hearing system based on the principle of bone conduction for the single-sided deafness (SSD) compensation, regardless of aetiology that may be congenital, vascular (Sudden Sensorineural Hearing Loss; SSNHL), infectious, traumatic, tumorous or iatrogenous. Patients and methodology: 59 patients with an SSD were examined between September 2010 and August 2014 and included into the study. The SSD aetiology included sudden hearing loss, temporal bone fracture, ototoxic effects of a treatment, chronic otitis and a growing vestibular schwannoma. Results: All patients were tested for the effect by the Baha Softband and 23 decided to undergo the surgery. During the entire course of the study, three generations of the Baha implants were used (BI300, BIA400, Attract) without any intraoperative or postoperative complications. The effectivity of the Baha system was shown during testing of a sentence comprehension in noise, with a significant improvement after six weeks and one year respectively. In this testing, the signal was coming to the deaf side and noise to the hearing side, on a loudness level of 65 dB SPL and 70 dB SPL, respectively. Conclusion: Baha represents an effective option for correction of patients with SSD. Patients should be offered to test an implantable and/or non-surgical options for compensation as part of routine care for patients with single-sided deafness.

• Keywords
• jednostranná hluchota, větná srozumitelnost v šumu, Softband,
• MeSH
• Audiometry, Speech statistics & numerical data   MeSH
• Adult MeSH
• Deafness diagnosis   etiology   surgery   MeSH
• Prosthesis Implantation methods   MeSH
• Hearing Loss, Unilateral * diagnosis   etiology   surgery   MeSH
• Bone Conduction * MeSH
• Middle Aged MeSH
• Humans MeSH
• Sound Localization MeSH
• Adolescent MeSH
• Young Adult MeSH
• Otologic Surgical Procedures MeSH
• Speech Perception physiology   MeSH
• Aged MeSH
• Hearing Aids * MeSH
• Patient Satisfaction statistics & numerical data   MeSH
• Treatment Outcome MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Research Support, Non-U.S. Gov't MeSH

BAHA implant methodology is proven safe and effective method, being used by over 50.000 patients worldwide. This is the only way of hearing rehabilitation in patients with a single sided deafness, disregarding the aetiology. The uniqueness of the BAHA system in patients with a single sided deafness consists in a transformation of sound to vibrations transmitted straight to the skull bones and than by a bone conduction into the contralateral inner ear. The project targeted to patients with a single sided deafness is aiming to a hypothesis of a rehabilitation of a binaural hearing in such patients, verification of a better understanding in a noisy environment and a resulting increase of a quality of life after BAHA implantation. Similar study on a new generation of a BAHA processor has not been published yet.

Použití BAHA implantátu je prokazatelně bezpečná a efektivní metoda, využívaná celosvětově více než 50 tisíci pacienty. U pacientů s jednostrannou hluchotou, nezávisle na etiologii, skýtá jedinou možnost rehabilitace sluchu. Unikátnost BAHA systému u pacientů s jednostrannou hluchotou spočívá v transformaci zvuku na vibrace přenášené přímo na kost lebky a kostním vedení přenášené do druhostranného, tedy nepostiženého, vnitřního ucha. Tento projekt zaměřený na skupinu pacientů s jednostrannou hluchotou si klade za cíl potvrdit či vyvrátit u této skupiny pacientů možnost rehabilitace binaurálního slyšení, ověřit zlepšení rozumění v hlučném prostředí a ověřit zlepšení kvality života po BAHA implantaci. Obdobná studie využívající novou generaci BAHA procesoru nebyla dosud publikována.

• MeSH
• Prosthesis Implantation MeSH
• Hearing Loss, Unilateral MeSH
• Cochlear Implantation MeSH
• Quality of Life MeSH
• Sound Localization MeSH
• Speech Perception MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• otorinolaryngologie
• NML Publication type
• závěrečné zprávy o řešení grantu IGA MZ ČR

Localization of sound source azimuth within horizontal plane uses interaural time differences (ITDs) between sounds arriving through the left and right ear. In mammals, ITDs are processed primarily in the medial superior olive (MSO) neurons. These are the first binaural neurons in the auditory pathway. The MSO neurons are notable because they possess high time precision in the range of tens of microseconds. Several theories and experimental studies explain how neurons are able to achieve such precision. In most theories, neuronal coincidence detection processes the ITDs and encodes azimuth in ascending neurons of the auditory pathway using modalities that are more tractable than the ITD. These modalities have been described as firing rate codes, place codes (labeled line codes) and similarly. In this theoretical model it is described how the ITD is processed by coincidence detection and converted into spikes by summing the postsynaptic potentials. Particular postsynaptic conductance functions are used in order to obtain an analytical solution in a closed form. Specifically, postsynaptic response functions are derived from the exponential decay of postsynaptic conductances and the MSO neuron is modeled as a simplified version of the Spike Response Model (SRM0) which uses linear summations of the membrane responses to synaptic inputs. For plausible ratios of time constants, an analytical solution used to describe properties of coincidence detection window is obtained. The parameter space is then explored in the vicinity of the analytical solution. The variation of parameters does not change the solution qualitatively.

• MeSH
• Action Potentials physiology   MeSH
• Humans MeSH
• Sound Localization physiology   MeSH
• Models, Neurological * MeSH
• Nerve Net physiology   MeSH
• Sensory Receptor Cells physiology   MeSH
• Synaptic Transmission physiology   MeSH
• Computer Simulation MeSH
• Auditory Pathways physiology   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

• Keywords
• HRTF,
• MeSH
• Models, Anatomic MeSH
• Echolocation physiology   MeSH
• Humans MeSH
• Sound Localization physiology   MeSH
• Prospective Studies MeSH
• Auditory Pathways MeSH
• Auditory Perception * physiology   MeSH
• Auditory Cortex physiology   MeSH
• Models, Theoretical * MeSH
• Virtual Reality MeSH
• Sound MeSH
• Sound Spectrography methods   instrumentation   utilization   MeSH
• Check Tag
• Humans MeSH

Interaural level difference (ILD) is one of the basic binaural clues in the spatial localization of a sound source. Due to the acoustic shadow cast by the head, a sound source out of the medial plane results in an increased sound level at the nearer ear and a decreased level at the distant ear. In the mammalian auditory brainstem, the ILD is processed by a neuronal circuit of binaural neurons in the lateral superior olive (LSO). These neurons receive major excitatory projections from the ipsilateral side and major inhibitory projections from the contralateral side. As the sound level is encoded predominantly by the neuronal discharge rate, the principal function of LSO neurons is to estimate and encode the difference between the discharge rates of the excitatory and inhibitory inputs. Two general mechanisms of this operation are biologically plausible: (1) subtraction of firing rates integrated over longer time intervals, and (2) detection of coincidence of individual spikes within shorter time intervals. However, the exact mechanism of ILD evaluation is not known. Furthermore, given the stochastic nature of neuronal activity, it is not clear how the circuit achieves the remarkable precision of ILD assessment observed experimentally. We employ a probabilistic model and complementary computer simulations to investigate whether the two general mechanisms are capable of the desired performance. Introducing the concept of an ideal observer, we determine the theoretical ILD accuracy expressed by means of the just-noticeable difference (JND) in dependence on the statistics of the interacting spike trains, the overall firing rate, detection time, the number of converging fibers, and on the neural mechanism itself. We demonstrate that the JNDs rely on the precision of spike timing; however, with an appropriate parameter setting, the lowest theoretical values are similar or better than the experimental values. Furthermore, a mechanism based on excitatory and inhibitory coincidence detection may give better results than the subtraction of firing rates. This article is part of a Special Issue entitled Neural Coding 2012.

• MeSH
• Action Potentials MeSH
• Sound Localization physiology   MeSH
• Models, Neurological * MeSH
• Neurons physiology   MeSH
• Olivary Nucleus physiology   MeSH
• Computer Simulation MeSH
• Poisson Distribution MeSH
• Space Perception physiology   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH