Although functional magnetic resonance imaging is an important tool for measuring brain activity, the hemodynamic blood oxygenation level dependent (BOLD) response is only an indirect measure of neuronal activity. Converging evidence obtained from simultaneous recording of hemodynamic and electrical measures suggest that the best correlate of the BOLD response in ...

The underwater hearing sensitivities of two 1.5-year-old female harbor seals were quantified in a quiet pool built specifically for acoustic research, by using a behavioral psychoacoustic technique. The animals were trained to respond when they detected an acoustic signal and not to respond when they did not ("go/no-go" response). Fourteen ...

The number of auditory filter outputs required to identify phonemes was estimated in two experiments. Stimuli were divided into 30 contiguous equivalent rectangular bandwidths (ERB(N)) spanning 80-7563Hz. Normal-hearing listeners were presented with limited numbers of bands having frequency locations determined randomly from trial to trial to provide a general view, ...

Subjects suffering from migraine with aura (MwA) present an altered cerebral autoregulation during migraine attacks. It is still unclear whether MwA sufferers present a normal autoregulation during attack-free periods. In this study, we characterized cerebral autoregulation in the frequency domain by analyzing the spontaneous oscillations superimposed on the cerebral hemodynamic ...

In two experiments, the peak-interval procedure was used with humans to test effects related to gaps in multisecond timing. In Experiment 1, peak times of response distributions were shorter when the gap occurred later during the encoding of the criterion time to be reproduced, suggesting that gap expectancy shortened perceived ...

We report what we believe to be the first demonstration of direct bandgap electroluminescence (EL) from Ge/Si heterojunction light-emitting diodes (LEDs) at room temperature. In-plane biaxial tensile strain is used to engineer the band structure of Ge to enhance the direct gap luminescence efficiency by increasing the injected electron population ...

We are examining the potential for cochlear implant patients who retain some low-frequency residual hearing in both ears to benefit from interaural time differences (ITDs) to improve speech reception. Given the likelihood of asymmetrical loss in the low-frequency region, the relationship between spectral overlap and ITD sensitivity is of interest. ...

Atlantic herring (Clupea harengus) has been observed in situ by the Kongsberg TOPAS PS18 parametric sub-bottom profiling sonar, with nearly horizontal transmit and receive transducer arrays mounted flush on the hull of RV G. O. Sars, at N71.4 E16.3. The primary frequencies are in the band 15-21 kHz, with nonlinearly ...

Changes in detection of a silent gap in a noise carrier with increasing carrier bandwidth and level may reveal effects of basilar-membrane nonlinearities on envelope fluctuations. Gap-detection thresholds are higher for narrowband than broadband noise carriers due to increased confusion between the imposed gap and inherent fluctuations of the narrowband ...

The present study investigated the relative influence of on- and off-frequency noise bands on speech recognition. The target speech stimuli consisted of 64 consonant-vowel consonants. The background noise was simplified speech spectrum-shaped noise or a sentence played backward. All stimuli were divided into 30 contiguous auditory filter width bands spanning ...

Dall's porpoise (Phocoenoides dalli) echolocation clicks have not been widely recorded. Concurrent with visual observations, acoustic recordings of free-ranging Dall's porpoise were made offshore of southern California using a towed hydrophone array with two elements of 250 kHz bandwidth. We examined 6035 clicks from 12 sessions totaling more than two ...

Many sounds in the environment have temporal envelope fluctuations that are correlated in different frequency regions. Comodulation masking release (CMR) illustrates how such coherent fluctuations can improve signal detection. This study assesses how perceptual grouping mechanisms affect CMR. Detection thresholds for a 1-kHz sinusoidal signal were measured in the presence ...

Animal studies have led to the view that the acoustic medial olivocochlear (MOC) efferent reflex provides sharply tuned frequency-specific feedback that inhibits cochlear amplification. To determine if MOC activation is indeed narrow band, we measured the MOC effects in humans elicited by 60-dB sound pressure level (SPL) contralateral, ipsilateral, and ...

Nothofagus betuloides (Coigue de Magallanes) is dominating in Tierra del Fuego, Chile, over large forested areas in pure stands, and in stands mixed with Nothofagus pumilio (Lenga). The natural regeneration of N. betuloides appears to be successful in canopy gaps as well as in the understorey of the adjacent stands. ...

Listeners with high-frequency dead regions (DRs) benefit from amplification of frequencies up to 1.7 times the edge frequency, f(e), of the DR. Better consonant identification might be achieved by replacing the band from f(e) to 1.7f(e) with a higher spectral band. We aimed to identify the optimal band, using simulations ...

The achromatic Mach bands effect is a well-known visual illusion, discovered over a hundred years ago. This effect has been investigated thoroughly, mainly for its brightness aspect. The existence of Chromatic Mach bands, however, has been disputed. In recent years it has been reported that Chromatic Mach bands are not ...

BACKGROUND: Under natural circumstances, attention plays an important role in extracting relevant auditory signals from simultaneously present, irrelevant noises. Excitatory and inhibitory neural activity, enhanced by attentional processes, seems to sharpen frequency tuning, contributing to improved auditory performance especially in noisy environments. In the present study, we investigated auditory magnetic ...

We investigate theoretically the coupling of exciton with light in a one-dimensional photonic crystal. The unit cell of the crystal consists of two alternating layers, namely a metallic layer and a semiconductor one. The frequency-dependent dielectric function of the metal is described by the Drude model, whereas for the semiconductor ...

The integration of auditory and visual information is required for the default mode of speech-face-to-face communication. As revealed by functional magnetic resonance imaging and electrophysiological studies, the regions in and around the superior temporal sulcus (STS) are implicated in this process. To provide greater insights into the network-level dynamics of ...

Graduation date: 1999

Currently, photonic crystals are attracting a lot of interest because of their ability to harvest light from a device into specific directions and wavelengths. In this work we have proven the theoretical prediction that in the case of an emission overlapping with the photonic stop band, the intensity is redistributed ...

Measurements of channel impulse response and its fluctuations in shallow water areas can be used for the prediction of sonar performance, the estimation of active and passive acoustic diver detections, and the prediction of channel characteristics relevant to underwater communication. A shallow water high-frequency propagation experiment was conducted in the ...

Extensive band structures are performed for two-dimensional periodic arrays of rigid stainless steel cylinders in air, with Bloch vector being perpendicular to the cylinders. We embark on the opening up of a complete acoustic band gap-independent of the polarization of the wave and of the direction of propagation. In addition, ...

In order to measure the internal structure of fluctuation, the broadband frequency tunable system, which has the ability of fast and stable hopping operation, is applied in the Large Helical Device. One of the important issues of density fluctuation measurements using this reflectometer is the study of energetic particle driven ...

Proponents of analog recording techniques have described their superiority over digitally sampled signals in part by referencing a theoretically infinite frequency band response. This is a typical argument used in favoring audiophile grade phonograph records to digitally sampled music. The actual frequency response of any individual transducer cartridge or phonograph ...

Stilp et al. [J. Acoust. Soc. Am. 122, 2971 (2007)] investigated the intelligibility of temporally desynchronized bands of speech and concluded that listeners's resilience to temporal asynchrony may possibly be due to differences in fundamental frequency (f(0)) across syllables which may help in segregating bands. This hypothesis is tested in ...

OBJECTIVES: The hypothesis that a natural auditory psychophysical discontinuity contributes to a perceptual category boundary between voiced and voiceless English stop consonants was examined. DESIGN: The relationships between voice onset time (VOT) phonetic boundary and gap-detection thresholds for conditions in which the sounds delimiting the gap were acoustically identical or ...

The frequency dependence of attenuation in marine sediments is investigated using in situ measurements from a wide-band acoustic probe system during the Shallow Water 2006 (SW06) experiment. Direct-path pulse propagation measurements within the 10-80 kHz frequency band show linear frequency dependency of attenuation in dBm at two silty-sand sites on ...

Electrocorticographic (ECoG) signals from the brain surface typically exhibit high synchrony across large cortical areas, interrupted by brief periods of desynchronization exhibiting propagating phase discontinuities, across which spatial patterns of phase emerge in selected frequency bands. Experiments with rabbits trained using classical conditioning paradigms indicated that such desynchronization periods demarcate ...

A temporal processing advantage is thought to underlie the left hemisphere dominance for language. One measure of a temporal processing advantage is temporal acuity or resolution. A standard paradigm for measuring auditory temporal resolution is gap detection in its "within-channel" and "between-channel" forms. Previous experiments investigating a right ear advantage ...

We investigated the pressure dependence of the Raman frequencies and intensities of the D and G bands of double-wall carbon nanotubes under strong uniaxial conditions. Using moissanite anvils, we observed for the first time the evolution of the D band under extreme stress/pressure conditions. We find that the difference between ...

BACKGROUND AND PURPOSE: To quantify respiratory motion of the vocal cords during normal respiration using 4D-CT. The final goal is to develop a technique for single vocal cord irradiation (SVCI) in early glottic carcinoma. Sparing the non-involved cord and surrounding structures has the potential to preserve voice quality and allow ...

Passive acoustic marine mammals detection and classification is of great importance nowadays. The goal of this article is to present a tool that can be used to accurately measure the duration of tonal emissions from marine mammals, helping to classify them. Marine mammals emissions can be split into two different ...

Two experiments investigated the effects of critical bandwidth and frequency region on the use of temporal envelope cues for speech. In both experiments, spectral details were reduced using vocoder processing. In experiment 1, consonant identification scores were measured in a condition for which the cutoff frequency of the envelope extractor ...

Two-hundred sentences of British English and Japanese, each uttered by 10 native speakers (5 females and 5 males) in each language, were analyzed through 20 bands of critical band filters. Smoothed power fluctuations derived from the filters were submitted to principal component analyses followed by varimax rotation. The first three ...

Speech was filtered into 16 frequency bands. Three bands were randomly selected on each trial as the LOW (two low-frequency bands) and HIGH (one high-frequency band) target components. LOW and HIGH were either presented to the same (SAME) or opposite (SPLIT) ears. Four randomly selected, nonoverlapping frequency bands from a ...

Narrowband noise stimuli were used to derive relative weights for detecting frequency glides in a yes/no procedure. One stimulus set was restricted to the duration of the glide. For the second stimulus set, there were fringe noise bands preceding and following the glide. For both sets, the center frequency of ...

The source properties of toothed whale echolocation clicks are essential for evaluating the performance of biosonar systems. However, such data only exist for a small number of free ranging toothed whale species. Here we present a quantitative analysis of the first recordings of echolocation sounds from hour glass dolphins (Lagenorhynchus ...

Preliminary findings reported at the 145th meeting of the Society suggested that confrontational tiger roars contain energy in the infrasonic portion of the electromagnetic spectrum. This discovery generally supported the proposition that free ranging individuals may take advantage of this capability to communicate with widely dispersed conspecifics inhabiting large territories ...

Whereas gamma-band neuronal oscillations clearly appear integral to visual attention, the role of lower-frequency oscillations is still being debated. Mounting evidence indicates that a key functional property of these oscillations is the rhythmic shifting of excitability in local neuronal ensembles. Here, we show that when attended stimuli are in a ...

This letter reports telecom-band sequential time-bin entangled photon-pair generation at a repetition rate of 10 GHz in periodically poled reverse-proton-exchange lithium niobate waveguides based on mode demultiplexing. With up-conversion single-photon detectors, we observed an entangled-photon-pair flux of 313 Hz and a two-photon-interference-fringe visibility of 85.32% without subtraction of accidental noise ...

Static and dynamic handgrip experiments are performed in order to evaluate the effectiveness of utilizing frequency-band wavelet analysis in measuring force and muscle fatigue simultaneously. SEMG signals are recorded from flexor muscle and analyzed using continuous wavelet transform (CWT). The wavelet coefficients are grouped into high frequency (65Hz - 350Hz) ...

We aim to analyze the frequency content of skin blood flow signals recorded on Hoku following acupuncture stimulation (AS). Each experiment involved recording a 20-minute control-data sequence and two effects data recorded 0-20 and 50-70 minutes after stopping AS, respectively. 4-level Haar-wavelet transform was performed on the measured LDF signals, ...

Many Brain-computer Interfaces (BCI) use band-power estimates with more or less subject-specific optimization of the frequency bands. However, a number of alternative EEG features do not need to select the frequency bands; estimators for these features have been modified for an adaptive use. The popular band power estimates were compared ...

A single elderly, dependent subject was monitored for a period of three months. Data were collected from 12 sensors in his apartment. We investigated new criteria for diagnosing abnormal events with more reliability. Initial results suggested that six diagnostic functions could be achieved using only presence sensors. These were: immobility ...

We aimed to identify neural oscillations in the time-frequency representation of local field potentials recorded from the subthalamic nucleus. The time-frequency representation was normalised over the global mean and standard deviation global normalisation, or against the baseline period at each frequency, local normalisation. The cross-correlation between beta and gamma oscillations ...

BACKGROUND: Gamma-band oscillations recorded from human electrophysiological recordings, which may be associated with perceptual binding and neuronal connectivity, have been shown to be altered in people with autism. Transient auditory gamma-band responses, however, have not yet been investigated in autism or in the first-degree relatives of persons with the autism. ...

OBJECTIVES: The objective of this study was to describe the cortical evoked response to silent gaps in a group of young adults with normal hearing using stimulus conditions identical to those used in psychophysical studies of gap detection. Specifically, we sought to examine the P1-N1-P2 auditory evoked response to the ...

This study examined within- and across-electrode-channel processing of temporal gaps in successful users of MED-EL COMBI 40+ cochlear implants. The first experiment tested across-ear gap duration discrimination (GDD) in four listeners with bilateral implants. The results demonstrated that across-ear GDD thresholds are elevated relative to monaural, within-electrode-channel thresholds; the size ...

Several listening conditions show that energy remote from a target frequency can deleteriously affect sensitivity. One interpretation of such results entails a wideband analysis involving a wide predetection filter. The present study tested the hypothesis that both temporal gap detection and overshoot results are consistent with a wideband analysis, as ...