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Results 451 - 500 of 1079
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Yoshikawa H - - 2000
Tone burst evoked otoacoustic emissions (TBEOAEs) were measured for two tone bursts presented separately and as a two-tone burst complex to examine the linearity of TBEOAE generators for different frequency separations of the stimuli. The stimuli were: (a) tone bursts of 5-ms duration and center frequencies of 1, 1.5, 2 ...
Fahey P F - - 2000
Suppression and/or enhancement of third- and fifth-order distortion products by a third tone that can have a frequency more than an octave above and a level more than 40 dB below the primary tones have recently been measured by Martin et al. [Hear. Res. 136, 105-123 (1999)]. Contours of iso-suppression ...
Plack C J - - 2000
Three experiments investigated the importance of perceived stimulus continuity for the perception of the fundamental frequency (F0) of an unresolved complex tone. The F0 of the complex was 250 Hz and the harmonics were bandpass filtered between 5500 and 7500 Hz. In the first experiment, F0 discrimination was measured for ...
Ohl F W - - 2000
The present study investigated the topography of epidurally recorded middle latency components P1 and N1 evoked by spectrally dynamic stimuli (linearly frequency-modulated (FM) tones) with respect to the tonotopic structure of the right primary auditory cortex, field AI. Whereas the gross topography corresponded to the spectral content of the FM ...
Rose M M - - 2000
This study examined the effect of center frequency and level on the perceptual grouping of rapid tone sequences. The sequence ABA-ABA-...was used, where A and B represent sinusoidal tone bursts (10-ms rise/fall, 80-ms steady state, 20-ms interval between tones) and - represents a silent interval of 120 ms. In experiment ...
Krumbholz K - - 2000
This paper is concerned with the lower limit of pitch for complex, harmonic sounds, like the notes produced by low-pitched musical instruments. The lower limit of pitch is investigated by measuring rate discrimination thresholds for harmonic tones filtered into 1.2-kHz-wide bands with a lower cutoff frequency, F(c), ranging from 0.2 ...
Tervaniemi M - - 2000
The pitch of a spectrally rich sound is known to be more easily perceived than that of a sinusoidal tone. The present study compared the importance of spectral complexity and sound duration in facilitated pitch discrimination. The mismatch negativity (MMN), which reflects automatic neural discrimination, was recorded to a 2. ...
Plack C J - - 2000
The experiment compared the pitches of complex tones consisting of unresolved harmonics. The fundamental frequency (F0) of the tones was 250 Hz and the harmonics were bandpass filtered between 5500 and 7500 Hz. Two 20-ms complex-tone bursts were presented, separated by a brief gap. The gap was an integer number ...
Fishman Y I - - 2000
Noninvasive neurophysiological studies in humans support the existence of an orthogonal spatial representation of pure tone frequency and complex tone pitch in auditory cortex [Langner et al., J. Comp. Physiol. A 181, 665-676 (1997)]. However, since this topographic organization is based on neuromagnetic responses evoked by wideband harmonic complexes (HCs) ...
Grimault N - - 2000
Two experiments investigated the influence of resolvability on the perceptual organization of sequential harmonic complexes differing in fundamental frequency (F0). Using a constant-stimuli method, streaming scores for ABA-... sequences of harmonic complexes were measured as a function of the F0 difference between the A and B tones. In the first ...
Hicks M L - - 2000
Across-frequency integration of complex signals was investigated by measuring psychometric functions [log (d') versus signal level in dB SPL] for detection of brief and long signals presented in broadband noise. The signals were tones at 630, 1600, and 4000 Hz, and a nine-tone complex with components spaced at one-third-octave frequencies ...
Farjampour P - - 2000
Discrimination of tone duration was studied as a function of menstrual cycle phase. In three phases of their menstrual cycle, 12 women compared the durations of 64 pairs of tones. They discriminated the tone durations least well in the premenstrual phase and tended to speed up their responding over sessions. ...
Ruusuvirta T - - 2000
Subjects compared pitches of a standard tone and a comparison tone separated by 1,300-3,000 msec and responded according to whether the comparison tone sounded higher or lower in pitch than the standard tone. Three interfering tones at 300-msec intervals were presented before each pair of tones. Their pitch range varied, ...
Wiegrebe L - - 2000
Recently, it was demonstrated that the pitch strength of a stimulus denoted "AABB" differed from rippled noise (RN) despite the fact that their long-term spectra and autocorrelation functions are identical (Wiegrebe et al., 1998). Rippled noise is generated by adding a delayed copy of Gaussian noise back to itself; AABB ...
Dent M L - - 2000
Studies of frequency resolving power in budgerigars (Melopsittacus undulatus) have shown that this species has excellent discrimination abilities for both simple and complex sounds falling in the region of 2 to 4 kHz--the frequency range of their contact call. In four experiments, frequency discrimination by budgerigars of short tones similar ...
Bregman A S - - 2000
Adult listeners rated the difficulty of hearing a single coherent stream in a sequence of high (H) and low (L) tones that alternated in a repetitive galloping pattern (HLH-HLH-HLH...). They could hear the gallop when the sequence was perceived as a single stream, but when it segregated into two substreams, ...
Marvit P - - 2000
In this report we present the first behavioral measurements of auditory sensitivity for Pollimyrus adspersus. Pollimyrus is an electric fish (Mormyridae) that uses both electric and acoustic signals for communication. Tone detection was assessed from the fish's electric organ discharge rate. Suprathreshold tones usually evoked an accelerated rate in naive ...
Menning H - - 2000
The slow auditory evoked (wave N1m) and mismatch field (MMF) elicited by sequences of pure tones of 1000 Hz and deviant tones of 1050, 1010 and 1005 Hz were measured before, during and 3 weeks after subjects were trained at frequency discrimination for 15 sessions (over 3 weeks) using an ...
Brunstrom J M - - 2000
The perceptual fusion of harmonics is often assumed to result from the operation of a template mechanism that is also responsible for computing global pitch. This dual-role hypothesis was tested using frequency-shifted complexes. These sounds are inharmonic, but preserve a regular pattern of equal component spacing. The stimuli had a ...
Walker B N - - 2000
Designing auditory displays requires understanding how different attributes of sound are processed. Operators must often listen to a particular stimulus dimension and make control actions contingent on the auditory information. Three experiments used a selective-listening paradigm to examine interactions between auditory dimensions. Participants were instructed to attend to either relative ...
Kerassidis S - - 2000
In the context of our investigation on palmar sweating and hyperhidrosis we subjected 40 individuals (20 hyperhidrotic and 20 normal) to noise stimulation. The participants received ten startling auditory tones (square pulse of 400 ms duration, 1000 Hz frequency and 105-dB intensity) at random intervals varying from 15-55 s. Hyperhidrotic ...
Henry J A - - 2000
This study addressed the clinical need to obtain frequency-specific auditory brainstem responses (ABRs) more rapidly than is currently possible. ABRs were obtained from 20 subjects using two different methods: a conventional method with tone bursts presented singly and a multiple-stimulus method using a train of 20 tone bursts. For both ...
Kaltenbach J A - - 2000
Intense tone exposure induces increased spontaneous activity (hyperactivity) in the dorsal cochlear nucleus (DCN) of hamsters. This increase may represent an important neural correlate of noise-induced tinnitus, a condition in which sound, typically of very high pitch, is perceived in the absence of a corresponding acoustic stimulus. Since high pitch ...
Tervaniemi M - - 2000
The effect of the spectral tone structure on pre-attentive and attentive pitch discrimination was investigated. The mismatch negativity (MMN) component was recorded from reading subjects to pitch changes of identical magnitude in pure tones with only one sinusoidal frequency component and in spectrally rich tones with two additional harmonic partials. ...
Schouten M E - - 2000
The aim was to find a psychophysical explanation for the perception, by naive listeners, of diphthongs as single vowels, even though they are essentially formant movements. Subjects were asked to match sinusoidal tone and resonance glides around 1,000 Hz with two connected steady-state tones or resonances whose frequencies could be ...
Baker K L - - 2000
Consecutive sounds of similar structure that are close in frequency or pitch are more likely to be perceived as part of the same sequence than those at greater frequency separations. The principle of grouping into such perceptual sequences, or auditory streams, is known as frequency proximity. However, the metric by ...
Mapes-Riordan D - - 1999
Recent research on loudness has focused on contextual effects on loudness, both assimilation and recalibration. The current experiments examined loudness recalibration [Marks, J. Exp. Psychol. 20, 382-396 (1994)]. In the first experiment, an adaptive tracking procedure was used to measure loudness recalibration as a function of standard- and recalibration-tone level. ...
Ciocca V - - 1999
Two experiments investigated the role of the regularity of the frequency spacing of harmonics, as a separate factor from harmonicity, on the perception of the virtual pitch of a harmonic series. The first experiment compared the shifts produced by mistuning the 3rd, 4th, and 5th harmonics in the pitch of ...
Clément S - - 1999
The decays of pitch traces and loudness traces in short-term auditory memory were compared in forced-choice discrimination experiments. The two stimuli presented on each trial were separated by a variable delay (D); they consisted of pure tones, series of resolved harmonics, or series of unresolved harmonics mixed with lowpass noise. ...
McKinney M F - - 1999
Although the physical octave is defined as a simple ratio of 2:1, listeners prefer slightly greater octave ratios. Ohgushi [J. Acoust. Soc. Am. 73, 1694-1700 (1983)] suggested that a temporal model for octave matching would predict this octave enlargement effect because, in response to pure tones, auditory-nerve interspike intervals are ...
Sänger P R - - 1999
OBJECTIVE: The aim of this study was to determine the role of nitric oxide (NO), as the primary neurotransmitter of non-adrenergic, non-cholinergic (NANC) innervation, in stone-diseased and stone-free human gallbladders. METHODS: Human gallbladder muscle strips were mounted in modified Krebs-Henseleit solution with atropine (1 mM), guanethidine sulfate (5 mM) and ...
Baer T - - 1999
Van Schijndel et al. [J. Acoust. Soc. Am. 105, 3425-3435 (1999)] proposed that the auditory system partitions the spectro-temporal domain into frequency-time (f-t) windows and that the characteristics of these windows could be explored by measuring intensity discrimination for Gaussian-shaped tone pulses presented just above their detection threshold in noise. ...
Abouchacra K S - - 1999
The purpose of this study was to measure air-conduction (AC) and bone-conduction (BC) hearing thresholds with pure-tone and filtered sound effect stimuli using standard audiometric equipment. A group of 20 young, normal-hearing listeners participated in the study. Pure-tone stimuli were 250, 500, 1000, 2000, and 4000 Hz. Sound effect stimuli ...
Vliegen J - - 1999
In a previous paper, it was shown that sequential stream segregation could be based on both spectral information and periodicity information, if listeners were encouraged to hear segregation [Vliegen and Oxenham, J. Acoust. Soc. Am. 105, 339-346 (1999)]. The present paper investigates whether segregation based on periodicity information alone also ...
Neuhoff J G - - 1999
Three experiments showed that dynamic frequency change influenced loudness. Listeners heard tones that had concurrent frequency and intensity change and tracked loudness while ignoring pitch. Dynamic frequency change significantly influenced loudness. A control experiment showed that the effect depended on dynamic change and was opposite that predicted by static equal ...
Inada N - - 1999
The damage-risk criterion (DRC) for hearing supposes that sound exposure with equal energy implies equal risk for noise-induced hearing loss (NIHL). We measured cochlear microphonics (CM), compound action potential (CAP), endocochlear potential (EP) and K+ ion concentration in the scala media, to see if the same level of Leq24h (impact ...
van Schijndel N H - - 1999
The just-noticeable difference in intensity jnd(I) was measured for 1-kHz tones with a Gaussian-shaped envelope as a function of their spectro-temporal shape. The stimuli, with constant energy and a constant product of bandwidth and duration, ranged from a long-duration narrow-band "tone" to a short-duration broadband "click." The jnd(I) was measured ...
Goodin D S - - 1999
Response latencies were measured in 6 parkinsonian patients and 6 normal subjects in a choice reaction task requiring the discrimination of two different tones with different probabilities of occurrence (frequent and rare). Response latency was measured from stimulus onset to onset of electromyographic activity in the responding muscle. Rare-tone responses ...
Paavilainen P - - 1999
The ability to extract invariant relationships from physically varying stimulation is critical for example to categorical perception of complex auditory information such as speech and music. Human subjects were presented with tone pairs randomly varying over a wide frequency range, there being no physically constant tone pair at all. Instead, ...
Krumbholz K - - 1999
The gleaning bat Megaderma lyra emits broadband echolocation sounds consisting of multiple frequency components. The present study investigates into which perceptual qualities the spectral characteristics of echoes may be translated in the auditory system of M. lyra. Three bats were trained in a 2-AFC behavioral experiment to classify nine complex ...
Coleman J R - - 1999
Audiogenic seizure susceptibility in the normally seizure-resistant Long-Evans rat may result from altered processing in the auditory pathway. Representative waveform latencies of the auditory brainstem responses (ABR) were recorded to examine generator alterations at different levels of the auditory neuraxis. Male Long-Evans rats primed for audiogenic seizures (AGS) on PND ...
Culling J F - - 1999
Huggins' pitch (HP) can be heard when listening to white noise which is diotic at all frequencies except for a narrow band over which the interaural phase of the noise changes progressively through 360 degrees. The detectability (d') of HP was measured for 11 center frequencies between 100 Hz and ...
Vaz Pato M - - 1999
In this study, synthesised instrumental tones were used to examine human auditory cortical processes engaged at the end of a period of rapid pitch modulation. It was previously [S.J. Jones, O. Longe, M. Vaz Pato, Auditory evoked potentials to abrupt pitch and timbre change of complex tones: electrophysiological evidence of ...
Sadralodabai T - - 1999
Two experiments investigated how listeners allocate their attention to different segments of a temporal pattern. The experiments allowed a direct test of the predictions of the Proportion of Total Duration (PTD) rule and the Component Relative Entropy (CoRE) model. Listeners had to decide whether two sequences of nine tones had ...
Mcintosh A R - - 1998
Large-scale functional connectivity in associative learning: interrelations of the rat auditory, visual, and limbic systems. J. Neurophysiol. 80: 3148-3162, 1998. Functional relations between specialized parts of the brain may be important determinants of learned behaviors. To study this, we examined the interrelations of the auditory system with several extraauditory structures ...
Talwar S K - - 1998
Frequency discrimination was investigated in the albino rat using a modified go/no-go positive reinforcement procedure in which subjects reported frequency increments in an ongoing series of pure tone bursts. Weber ratios (frequency difference limen/frequency) were measured from 5 to 32 kHz at 50 dB sound pressure level. A signal detection ...
Brunstrom J M - - 1998
The basis for the perceptual cohesion of periodic complex tones was investigated. In experiment 1, 2-4 consecutive components (harmonics 6 and above) were removed from a 14-harmonic complex and replaced with a sinusoidal "probe," located at one of a set of regularly spaced positions spanning the gap. On each trial, ...
McKibben J R - - 1998
Acoustic signal recognition depends on the receiver's processing of the physical attributes of a sound. This study takes advantage of the simple communication sounds produced by plainfin midshipman fish to examine effects of signal variation on call recognition and preference. Nesting male midshipman generate both long duration (> 1 min) ...
Boltz M G - - 1998
The purpose of this research was to investigate a set of factors that may influence the perceived rate of an auditory event. In a paired-comparison task, subjects were presented with a set of music-like patterns that differed in their relative number of contour changes and in the magnitude of pitch ...
Lane S D - - 1998
This study employed a stimulus-class rating procedure to explore whether stimulus equivalence and stimulus generalization can combine to promote the formation of open-ended categories incorporating cross-modal stimuli. A pretest of simple auditory discrimination indicated that subjects (college students) could discriminate among a range of tones used in the main study. ...
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