Contrary to level detection models, the thresholds for a brief-duration probe masked by a sinusoidal frequency modulation (FM) masker increases as the modulation index (beta) of FM increases [Zwicker, Acustica 31, 243-256 (1974)]. In this paper the reason for this phenomenon is investigated. In experiment 1, a 10-ms, 1-kHz probe ...

The purpose of this communication is to describe a new method for predicting masking level differences (MLDs) as a function of the interaural correlation of the masking noise. The general idea is to decompose a binaural noise masker having an arbitrary value of interaural correlation into two parts: an No ...

Signal detectability was measured in three temporal conditions as a function of the bandwidth and configuration of simultaneous maskers that either did or did not spectrally overlap the signal. The 20-ms signal was 250 Hz wide and was centered at 2500 Hz (fs). Although there were marked individual differences, performance ...

An investigation was made of the time course of perceptual grouping that is based on two qualitatively different spatial relationships: proximity and alignment. An index of grouping capacity was used to assess the processing time required before a backward pattern mask interfered with grouping. Stimuli consisted of bistable arrays of ...

This study describes the variations in the reproducibility of attachment level recordings for different subjects at different examinations. Twenty patients with different degrees of periodontal disease were recruited and examined bi-monthly for their attachment levels using an electronic probe in two quadrants and a conventional probe in the other two ...

An attempt has been made to relate the masking effects studied under dichotic listening conditions to masking seen in the free field. Rather than use a free-field masking paradigm combined with monaural and binaural listening conditions, broadband maskers presented in virtual auditory space (VAS) have been used. Two virtual locations ...

Contralateral masking occurs when the threshold of a signal in one ear is elevated by the presence of a masker in the other, contralateral ear. The classic data and theory on contralateral masking were provided by Zwislocki [J. Acoust. Soc. Am. 52, 644-659 (1972)] who observed a 3- to 18-dB ...

Two-tone suppression and notched-noise signal enhancement (overshoot) were measured at 1000 Hz using standard procedures in 40 normal-hearing, naive adults, counterbalanced for sex, listening ear, and testing order. The threshold range across subjects for the same condition often exceeded 30 dB. In the suppression conditions, for some subjects the 20-ms ...

This study examined the effects of multicomponent, random-frequency maskers and broadband-noise maskers on intensity discrimination at 1000 Hz. Maskers and signals were 200 ms, presented simultaneously. In the first set of conditions, thresholds were measured for the detection of a 1000-Hz tone in the presence of 40 or 60 dB ...

The upward spread of masking was compared for 500-Hz quasifrequency-modulated (QFM) and sinusoidally amplitude-modulated (SAM) maskers. The modulation rate was 20 Hz. These maskers had identical magnitude spectra but different envelopes, which were relatively flat for the QFM masker and strongly fluctuating for the SAM masker. At signal frequencies more ...

When a pair of tonal stimuli of different frequencies (F1 and F2, where F2 > F1) are simultaneously presented to the ear, an electrical response with a frequency of F2-F1 can be recorded from the round window (RW) of the gerbil's cochlea. By using phase-locked tones of alternating polarity, the ...

There is a large deterioration in intensity discrimination performance at medium levels for a 30-ms sinusoidal pedestal presented 100 ms before or 100 ms after an intense masker [Plack and Viemeister, J. Acoust. Soc. Am. 92, 3097-3101 (1992)]. It has also been demonstrated that the loudness of a 30-ms sinusoidal ...

The role of orthographic neighborhood (neighborhood size and neighborhood frequency) in visual-word recognition was analyzed using the masked repetition-priming paradigm. Specifically, we varied stimulus-onset asynchrony (33, 50, and 67 msec.) and type of prime (identical, unrelated, unprimed) in a lexical decision task. Analyses show additive effects of repetition and stimulus-onset ...

Explanations for the phenomenon known as comodulation masking release (CMR) generally assume that temporal envelope information from different peripheral filters is compared, thus entailing multiple envelope representations. Here it is shown that a leaky-integrator model, yielding a single envelop representation extracted from a broad frequency range, provides an alternative account ...

Interactions between filters tuned to different orientations and spatial locations were investigated with a masking paradigm. Targets were masked by pairs of Gabor signals presented either at a different orientation (+/- delta theta) or at a different spatial location (+/- delta y). The two mask components were either of equal ...

Long-range spatial interactions in human visual cortex were explored using a lateral masking paradigm. Visual evoked potentials (VEPs) elicited by a Gabor signal presented in isolation or in the presence of two flanking high-contrast Gabor signals (masks) were measured. Response amplitude and phase were recorded for a vertically oriented test, ...

Brief (10 msec) increments, presented on a white adapting background, are known to elicit a spectral sensitivity function with a broad mid-spectral peak (King-Smith & Carden, 1976). We have found that a luminance decrement, presented as either a forward or backward mask, dramatically alters the form of the resultant sensitivity ...

This study tests the hypothesis that comodulation masking release (CMR) is mediated by "listening in the valleys" [S. Buus, J. Acoust. Soc. Am. 78, 1958-1965 (1985)]. Detectability was measured for signals consisting of six consecutive 25-ms, 1-kHz tone pulses presented in a 50-Hz-wide masker or in maskers consisting of seven ...

A correlation technique was used to assess the decision rules of three listeners in two cases of spectral-shape discrimination tasks. In one case the signal frequency was fixed, and in the other it was randomly varied within each block of trials. In order to estimate the decision rule of the ...

Contralateral sound stimulation produces suppression of transient evoked otoacoustic emission (TEOAE), which is attributed to a reflex activation of the medial olivocochlear system. More pronounced suppression of TEOAE produced by ipsilateral masking could involve efferent-mediated effects along with effects of cochlear origin. However, this has not been investigated so far. ...

Low-frequency masking is a new method for the diagnosis of endolymphatic hydrops. A short acoustic stimulus and a low-frequency masker tone are applied to the same ear in an adjustable phase relationship. We recorded phase-dependent masked thresholds from normal-hearing subjects, and patients with Ménière's disease and sensory hearing loss without ...

This study examined the effect of ear canal occlusion and masking noise on four parameters of voice: (1) average fundamental frequency, (2) intensity in decibel (dB), (3) maximum fundamental frequency observed in a given sample (max), and (4) minimum fundamental frequency observed in a given sample (min). 12 normal hearing ...

Overshoot--in particular, threshold for a signal near masker onset--can be reduced by presenting a stimulus (precursor) just prior to masker onset. The recovery of overshoot can be examined by varying the delay between the offset of the precursor and the onset of the masker, where "recovery" denotes an increase in ...

Tinnitus isomasking contours were determined for unmasked tinnitus and for tinnitus partially masked by high-pass noise. The noise was selected so that it masked all but the low frequency components of the tinnitus. As a control, the masking pattern of an external tone in the tinnitus region and in the ...

As in the case of auditory brainstem responses (ABRs) to air-conducted stimuli, recording of frequency-specific ABRs to bone-conducted stimuli needs adequate masking of those parts of the basilar membrane that are not to contribute to the ABR. The present study shows that tone-pulse stimulation with notched noise-masking can be realized ...

A series of experiments investigated listeners' ability to encode the fundamental frequency (F0) of a group of harmonics (the "target") in the presence of a second, spectrally overlapping, group (the "masker"). Experiment 1a was a sequential F0 discrimination task between two targets, whose F0s were geometrically centered on 210 Hz, ...

The threshold for detecting a change in orientation away from the vertical of a briefly presented foveal line target is raised when there are immediately following visual presentations. This masking effect was examined by measuring the capacity of a variety of patterns to act as masks. When patterns were made ...

Tactile thresholds for detecting a 50-ms signal presented 25 ms after the termination of a masking stimulus increased as a function of the amplitude level and duration of the masking stimulus. The effects were similar in both the P and NP I channels measured at 250 and 20 Hz, respectively. ...

As three-dimensional auditory displays become more prevalent, there will be an increasing need to understand the interactions that can be expected among spatially separated sounds. A two-alternative, forced-choice, adaptive staircase procedure was used to measure the detectability of a 165-ms click-train signal masked by a continuous Gaussian noise, as a ...

Many sensory discriminations, including the discrimination of speed, obey Weber's law and thus become more difficult as the stimuli get larger. Using one-jump apparent motion stimuli, we find that the opposite can occur: displacement discrimination improves with larger jumps. This pedestal effect occurs for small jumps near and below the ...

Tactile thresholds for detecting a 250-Hz signal of variable duration presented at variable times after the termination of a 250-Hz 700-ms masking stimulus were measured. It was found that the threshold shift resulting from the presentation of the masking stimulus declined as functions of the duration of the signal and ...

The purpose of this study was to determine whether comodulation masking release (CMR) and across-channel masking (ACM) are by-products of a similar across-channel mechanism. This was addressed by examining how the two are affected by stimulus manipulations expected to influence their magnitude. Subjects were required to detect a 1000-Hz signal ...

When a complex stimulus is presented, new frequencies (distortion products, DPs) are generated within the cochlea. The most intense DPs are lower in frequency than the stimulus tones (primaries). It is not clear whether the relative phase of stimuli is encoded by neural channels tuned to the primaries or by ...

This study examined the possibility that age-related differences in speech discrimination abilities may reflect individual differences in the amount of masking and in the rate of growth of on- and off-frequency masking. Young (mean age = 26 years) and older (mean age = 60 years) adult listeners were selected, all ...

The improvement in signal detectability as signal onset is delayed from masker onset was measured as a function of signal bandwidth for wideband and notched-noise maskers. The signal was centered at 2500 Hz. In two conditions, the 20-ms signal was gated 1 or 250 ms after the onset of a ...

The effects of contralateral noise on the masked compound action potential (CAP) were examined in human subjects. Small but significant enhancements of masked CAP amplitude (anti-masking effects) were observed in some patients with facial palsy, as well as in some subjects with healthy ears when noise was added to the ...

Listeners were trained to identify six patterns of eight sequentially presented 48-ms tone bursts. The variation in frequency forming the patterns was confined to a relatively narrow range around the nominal center frequency, which was either 500, 1000, or 3000 Hz, or was selected randomly on each presentation from a ...

What is the relation between the identifiability of masked flankers and their ability to induce compatibility effects in a letter classification task? Using a within-subjects design (n = 8), we first determined identification performance for two flankers (H or N) around an irrelevant target letter as a function of the ...

Large amounts of simultaneous masking can be produced by changing the frequency content of multicomponent maskers with each presentation. Much of this masking appears to be informational, that is, produced by stimulus uncertainty. This study examined whether relatively simple changes in the properties or presentation mode of the signal could ...

The effects of combining two equally effective maskers were studied in normally hearing and elderly hearing-impaired subjects. The additivity of nonsimultaneous masking was investigated by measuring thresholds for a brief 4-kHz signal in the presence of a broadband-noise forward masker, a backward masker, and a combination of both. For the ...

Three female adult chickens were trained to detect pure tones using a positive reinforcement technique and an adaptive threshold tracking procedure. Masked thresholds for tone bursts were measured in the presence of pure-tone maskers at 500, 1000, and 2000 Hz. Masker levels of 40-, 60-, and 70-dB sound-pressure level (SPL) ...

Coherent directional motion can be seen if an image is displayed in two sequential frames (F1 and F2), where F2 is a translated version of F1. A similar two-frame sequence can produce metacontrast masking: the visibility of a leading target (F1) is reduced by a trailing, spatially nonoverlapping mask (F2). ...

In the first phase of the study, detection thresholds were obtained in conditions that were associated with comodulation masking release (CMR), conditions that were associated with the masking-level difference (MLD), or conditions that were not associated with masking release (baseline conditions). In the second phase of the study, amplitude discrimination ...

Studies of tuning in infants have reported that auditory brain-stem response (ABR) tuning curves generated using low-frequency probes are adultlike by 3 months of age while high-frequency tuning curves remain immature [Folsom and Wynne, J. Acoust. Soc. Am. 81, 412-417 (1987)]. Behavioral studies have similarly reported adultlike low-frequency psychoacoustic tuning ...

Individual differences were examined for 49 listeners in a simultaneous-masking task with random-frequency, multicomponent maskers and a 1000-Hz signal. Across conditions, the maskers were broadband noise or complexes of 2-100 sinusoids whose frequencies were randomly chosen with each presentation. Maskers were equal rms waveforms, presented at 60 dB SPL. Thresholds ...

Comodulation masking release (CMR) describes the reduced masking of a pure tone when the masking is a noise that is coherently amplitude modulated (comodulated) over the total range of the spectrum compared to masking by an unmodulated noise of the same bandwidth and overall energy. The masking release results from ...

Stimulating the visual system tends to desensitize it to certain stimulus properties. Such desensitization is usually called adaptation or masking, but the distinction between the two is unclear. Nonspecific desensitization by light is usually regarded as adaptation, whereas pattern-specific desensitization is typically considered masking. Here we unify the treatment of ...

The echolocation transmission beam pattern of a false killer whale (Pseudorca crassidens) was measured in the vertical and horizontal planes. A vertical array of seven broadband miniature hydrophones was used to measure the beam pattern in the vertical plane and a horizontal array of the same hydrophones was used in ...

Thresholds for the detection of decrements in level of sinusoidal signals were measured as a function of decrement duration, level (25, 40, 55, and 70 dB SPL) and frequency (250, 1000, and 4000 Hz) in eleven normally hearing subjects. Thresholds for detecting a brief increment in level were also measured. ...

From experiments in animals and investigations in humans it is known that the normally phase-dependent masking of a short stimulus by a low-frequency continuous tone does not occur in the case of endolymphatic hydrops. The recording of the masked threshold of short tone stimuli in a loud tone of 30 ...