Alfvén in his early work on the origin of the solar system (1942-1946) noted a pronounced band structure in the gravitational potential distribution of secondary bodies, and suggested this feature to be directly related to the formation process. When the critical velocity phenomenon was later discovered, a close agreement was ...

In experiment I, thresholds for 400-ms sinusoidal signals were measured in the presence of a continuous 25-Hz-wide noise centered at signal frequencies (fs) ranging from 250 to 8000 Hz in 1-oct steps. The masker was presented either alone or together with a second continuous 25-Hz-wide band of noise (the flanking ...

Results of experiments on the detection of silent intervals, or gaps, in broadband noise are reported for normal-hearing listeners. In some preliminary experiments, a gap threshold of about 2 ms was measured. This value was independent of the duration of the noise burst, variation of the noise level on each ...

Waveforms that yield comodulation masking release (CMR) when they are presented simultaneously with a signal were used in a standard forward-masking procedure. The signal was a 25-ms sample of a 2500-Hz tone. The masker was a band of noise centered at 2500 Hz, 100 Hz in width, and 200 ms ...

The ability to discriminate between simultaneously presented 100-Hz-wide bands of noise with envelopes that were either similar or dissimilar was measured. The center frequencies of the noise bands, fL and fL + delta f Hz, were systematically varied. When the bands of noise were separated by an octave, delta f ...

In two preliminary experiments, listeners were instructed to limit increasingly the movement of their heads and/or bodies while attempting to localize narrow bands of noise centered on 2.3 or 8.3 kHz. With increasing constraint on movement, the high-frequency band was incorrectly perceived as elevated above the horizon. The low-frequency band, ...

Ultrasonic waveforms backscattered from tissue simulating phantoms and from normal and cirrhotic human livers in vivo were digitized to a standard dynamic range prior to envelope detection and determination of envelope amplitude distributions. For 11 individual narrow-band Gaussian-shaped filters of -6 dB bandwidth 200 kHz, and of center frequencies from ...

Subjects with cochlear impairments often show reduced temporal resolution as measured in gap-detection tasks. The primary goals of these experiments were: to assess the extent to which the enlarged gap thresholds can be explained by elevations in absolute threshold; and to determine whether the large gap thresholds can be explained ...

The minimum sensation levels required for optimal temporal gap resolution were measured in five listeners with moderately severe degrees of sensorineural hearing loss. The stimuli were three continuous octave-band noises centered at 0.5, 2.0, and 4.0 kHz. Subjects used a Békésy tracking procedure to determine the minimum signal levels needed ...

An experiment was performed to study the interaction of two narrow-band noises having correlated temporal envelopes. The detection threshold of a 100-Hz-wide noise-band signal was measured at different center frequencies in the presence of a continuous 100-Hz-wide noise band having a center frequency of 1000 Hz. The two noise bands ...

Three-channel Lissajous' trajectories (3-CLT) of the auditory brain-stem evoked potentials were recorded from 14 adult subjects in response to different frequency bands as well as to unmasked clicks. The frequency bands (8 kHz and above, 4-8 kHz, 2-4 kHz, 1-2 kHz and 1 kHz and under) were obtained by subtraction ...

A series of experiments was performed to study the ability of the ear to code the temporal envelope of a waveform as demonstrated by comodulation masking release (CMR). The stimulus for all experiments was composed of a tone-burst signal, a 100-Hz-wide masker band centered at the signal frequency, and a ...

Temporal gap resolution was measured in five normal-hearing listeners and five cochlear-impaired listeners, whose sensitivity losses were restricted to the frequency regions above 1000 Hz. The stimuli included a broadband noise and three octave band noises centered at 0.5, 1.0, and 4.0 kHz. Results for the normal-hearing subjects agree with ...

One can construct narrow bands of noise that contain delays of either the envelope, the phase, or the carrier separately or in combination. Delayed and undelayed noises will have identical spectra if, and only if, both the envelope and the phase undergo delays of the same magnitude. To study lateralization ...

The phenomenon of comodulation masking release (CMR) was studied in a series of experiments. When the relative level of the correlated cue band was more than about 10 dB less than that of the masker band, the CMR was abolished. When the duration of the tonal signal was varied with ...

Normal-hearing young adults (5 M, 6 F) were exposed monaurally for 3 min to narrow-band noises centered at .5, 1, and 4 kc/s, at 20 db above respective acoustic reflex (AR) thresholds. Strip-chart recordings (1 mm/sec) of middle-ear muscle contractions were graphed and evaluated for peak amplitude, latency, adaptation, and ...

The development of GaAsP/GaP devices was made for stacking on silicon bottom cells to achieve high conversion efficiencies. The estimated efficiency of the completed devices was 21% AMO under concentrated light. A four terminal sack was incorporated to allow voltage matching wiring schemes to account for differing degradation of the ...

Lateralization of narrow bands of noise was investigated while varying interaural temporal disparity (ITD), center frequency, and bandwidth, utilizing an acoustic pointing task. Stimuli were narrow bands of noise centered at octave intervals between 500 Hz and 4 kHz with bandwidths ranging from 50-400 Hz. In a second experiment, lateralization ...

The amplitude of wave V of the auditory brainstem response (ABR) has been found to vary in a manner consistent with the psychophysical critical band data. When the frequency separations between members of a tone pair, displaced symmetrically around some center frequency, exceed some critical value, the amplitude of wave ...

A new method is suggested for the fitting of a broad-band analogue cochlear prosthesis in terms of frequency response adjustment. This 'frequency-stepped sweep' (FSS) method employs a feedback loop including the patient's loudness judgement to determine a frequency response for the patient's sound processor with which a continuous sinusoidal stimulus ...

The natural communication behavior of frogs has provided a framework for studying both the mechanisms and evolution of sound pattern recognition. In the green treefrog behavioral studies using synthetic stimuli have identified the pertinent acoustic properties of its complex but stereotyped vocal signals. There are two optimal frequency bands: the ...

We studied the tonotopic organization in the inferior colliculus of the rat with the 2-deoxyglucose method. Isofrequency bands were observed in the central nucleus of the inferior colliculus. In coronal sections, higher sound frequencies elicited bands that were located more ventrally. At caudal levels of the inferior colliculus, isofrequency bands ...

Conventional (0.125-8 kHz) and high-frequency (8-20 kHz) audiometry, together with brainstem response audiometry supplemented with derived-band studies have been performed in 6 patients with sensorineural hearing loss: 1 with narrow-band, 3-4 kHz, and 5 with low-frequency threshold elevations. The derived-band results in the latter indicate that the low-frequency audiometric thresholds ...

The cat inferior colliculus (IC) was studied with 2-deoxyglucose (2-DG). By presenting high-frequency tone bursts to one ear and white noise bursts simultaneously to the other, a band of reduced or inhibitory labeling was revealed in the central nucleus (ICC) of the IC ipsilateral to the ear receiving the tone ...

Estimates of auditory temporal acuity were obtained from normal chinchillas by measuring their gap-detection thresholds using wideband noise over a range of intensities. Afterwards, the animals were exposed to high-intensity noise whose low-frequency cutoff was progressively lowered towards the low frequencies in five 1-oct steps. The five exposures resulted in ...

The auditory brainstem responses evoked by click, noise-burst and tone-bursts have been recorded in the cat, and octave-wide derived bands obtained at 20 and 50 dB RL intensity levels. At near-threshold intensity both the 2 and 4 kHz tone-bursts are frequency specific, while the click and noise-burst ABR contain no ...

Thresholds were measured for the detection of a temporal gap in a bandlimited noise signal presented in a continuous wideband masker, using an adaptive forced-choice procedure. In experiment I the ratio of signal spectrum level to masker spectrum level (the SMR) was fixed at 10 dB and gap thresholds were ...

Binaural masking level differences (MLDs) were measured for 10 normal-hearing and 10 cochlear-impaired listeners, at 500 and 2 000 Hz. Maskers were either wide-band (approximately 2 000 Hz), or narrow-band (50 Hz). For wide-band maskers the noise pressure spectrum level was 50 dB/Hz, and for the narrow-band maskers the noise ...

In laboratory rats (as in humans) a low-intensity tone that precedes a high-intensity burst of noise by approximately 100 ms can reduce the amplitude of the startle reaction elicited by the burst of noise. A series of four experiments with rats investigated the relation between the inhibitory effects of tonal ...

Band-narrowing estimates of the critical bandwidth (CB) are consistently larger than critical-ratio (CR) estimates for the same signal frequency. Bilger [in Hearing and Davis: Essays Honoring Hallowell Davis, edited by S.K. Hirsh et al. (Washington U.P., St. Louis, 1976), p. 191] proposed that this difference could be accounted for by ...

The relation between the monaural critical band and binaural analysis was examined using an NoSm MLD paradigm, in order to resolve ambiguities about the width of the masking spectrum important for binaural detection. A 500-Hz pure-tone signal was presented with a 600-Hz-wide band of masking noise to the signal ear. ...

Recent studies of temporal resolution in hearing-impaired listeners indicate that many ears with cochlear damage exhibit elevated temporal gap thresholds. The deviations from normal may be large, for equivalent-SPL comparisons, but are often small or absent for equivalent-SL comparisons. In the present experiment, we examine the premise that SL effects ...

Temporal resolution was examined in normal-hearing subjects using a broadband noise and five narrow-band noises with center frequencies (fc) spaced 2 kHz apart between 6 and 14 kHz. Bandwidths of the narrow-band signals were equal to 0.16 fc, and broadband noise maskers with spectral notches were used to restrict the ...

2-Deoxyglucose experiments were carried out during which tone bursts were presented to one ear of cats, while white noise bursts were presented to the other ear. Autoradiography revealed that the tones had produced clear bands of reduced labelling in the ipsilateral inferior colliculus, in addition to the expected band of ...

An experiment was conducted in order to compare the importance of information from frequency regions remote from the nominal signal frequencies for frequency discrimination and signal detection. In both tasks, signals were presented within the "notch" of band-reject noise, and different notch widths were employed. The results indicate that information ...

The threshold for detection of a temporal gap in a noiseband was measured. A notched noise masker was used to restrict listening to a limited spectral region. Threshold was measured as a function of center frequency, bandwidth, and level. For a signal bandwidth of one-half the center frequency, the gap ...

Pronounced bright and dark bands are seen at the bright and dark edges of half-shadows and similar distributions of illumination. These are the so-called Mach bands. A pair of vertical Mach bands was generated with a ramp pattern in the central strip of a horizontal tripartite oscilloscope display. This pattern ...

Temporal gap resolution is measured with Békésy tracking procedure and filtered noise stimuli in the frequency range below 6000 Hz. Stimulus parameters include high-pass and low-pass cutoff frequency, band center frequency, bandwidth in a 2-oct range, and signal level in the low-to-moderate intensity range. The pattern of results indicates that ...

Experiments were conducted to assess the contribution of place mechanisms to the effect of rise--fall time on wave V of the human brainstem auditory evoked response (BAER). Noise bursts of 4- and 10-ms duration were presented at various rise-fall times (0, 1, 2, and 5 ms). Subtractive high-pass masking techniques ...

We attempted to resolve the issue on the location of breakages in patients with structural rearrangements, that is, whether they are located within the light band or are at the interface between a G-dark and a G-light band. Three types of structural rearrangements (inverted duplications, isodicentrics, and rings) were studied ...

This study examines how simultaneous masking of a tone by bandlimited noise may be affected by nonlinear interactions among spectral components of the noise. Simultaneous masking patterns (signal threshold versus signal frequency) were obtained with three types of maskers: (A) a narrow-band noise, 50 Hz wide with variable center frequency ...

Nonlinearity and asymmetrical property in the filling-in process at the blind spot are investigated. Perceptual completion of a pattern with a gap is deteriorated, i.e. gap information inhibits completion across the gap. Filled-in patterns, observed from complementary patterns, are not the same in complementary sense. These suggest that perceptual completion ...

The ergometer is mechanically braked by a band in series with a spring. Each end of the band passes over one of two spherical ball bearings, and is attached to the free end of a spring steel bar mounted on the same plate as the two ball bearings. By means ...

In chicks, monaurally deafened at 3 weeks of age, 2-deoxyglucose labeling of the input layer L2 in the auditory neostriatum (field L) was analyzed after acoustic stimulation. Two types of stimuli were used: narrow band frequency modulations and white noise. Both stimuli provide evidence that there are bands or columns ...

Two series of perceptual experiments have been conducted to investigate the level of noise that acts as a threshold of degradation (TOD) when band-limited noise is added to speech such that the noise is either constrained to lie in one subband of the entire speech band or separately introduced into ...

Temporal resolution, estimated by measuring the minimum detectable gap (delta t ms) separating two successive signals, was assessed in five normal-hearing and five cochlear-impaired listeners. The signals were octave-band noises (400-800 Hz, 800-1600 Hz, and 2000-4000 Hz) presented in a background of continuous, broadband notched noise that was applied to ...

The minimum detectable duration of a brief burst of noise and a brief gap in a noise were measured by the two-alternative forced-choice method. For all listeners the minimum detectable duration of a burst was shorter than the minimum detectable duration of a gap at equal signal-to-noise ratios. For 12 ...

The design of a low-cost 1/3 octave-band noise generator is presented. This device produces 1/3 octave bands of noise with center frequencies from 100 to 10,000 Hz using a recently introduced switch-capacitor filter with a frequency response which is similar to that of the 1/3 octave filters in the GR ...

Speech discrimination of place-loaded Modified Rhyme test words in speech-babble and cafeteria noise by elderly hearing-impaired subjects was measured. The stimuli were presented under the following conditions: (1) monotic: the signal was presented to the preferred ear; (2) low-frequency attenuated: the frequency band below 1,000 Hz was attenuated by 5, ...

Heterodyne difference frequency measurements between a (13)CO(2) laser and a diode laser tuned (and in most cases locked) to the peaks of OCS absorption lines have been used to improve frequency calibration tables in the 860-cm(-1) region by factors of 20-50. Measurements have been made on the vibrational transitions 10(0)0-00(0)0, ...