Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Loudness Perception”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

Intensity discrimination and increment detection at 16 kHz.

When presented for several seconds, a very high-frequency tone can decay to inaudibility in subjects with normal hearing. The purpose of the present study was to determine how such a tone behaves once it is inaudible. Intensity difference limens (DLs) at 16 kHz were measured for gated (audible) and continuous (inaudible) pedestals over a range of pedestal sensation levels from about 0-60 dB, and were compared with those obtained in the same two subjects at 1 kHz [N. F. Viemeister and S. P. Bacon, J. Acoust, Soc. Am. 84, 172-178 (1988)]. The results at the two frequencies were remarkably similar, indicating, among other things, that a continuous 16-kHz pedestal--despite being inaudible-behaves as if it were audible. In addition, the results suggest that there is little or no relationship between high-frequency tone decay and intensity DLs. The locus of this long-term adaptation effect is presumably peripheral to the site where binaural interactions occur, and may be at the hair cell or auditory nerve. The intensity DLs are more consistent with a multiplicative model of (long-term) adaptation than with a subtractive model, suggesting that the nature of this adaptation is different from that which characterizes short-term adaptation.

Acoustic Stimulation↗

Cross-modal integration of simple auditory and visual events.

Responses are typically faster and more accurate when both auditory and visual modalities are stimulated than when only one is. This bimodal advantage is generally attributed to a speeding of responding on bimodal trials, relative to unimodal trials. It remains possible that this effect might be due to a performance decrement on unimodal ones. To investigate this, two levels of auditory and visual signal intensities were combined in a double-factorial paradigm. Responses to the onset of the imperative signal were measured under go/no-go conditions. Mean reaction times to the four types of bimodal stimuli exhibited a superadditive interaction. This is evidence for the parallel self-terminating processing of the two signal components. Violations of the race model inequality also occurred, and measures of processing capacity showed that efficiency was greater on the bimodal than on the unimodal trials. These data are discussed in terms of a possible underlying neural substrate.

Attention↗

Magnitude estimation scaling of the loudness of a wide range of auditory stimuli.

The study of the perception of loudness lends itself well to the psychophysical scaling technique of magnitude estimation. This study was designed to extend the range of auditory stimuli used to study the magnitude estimation scaling of loudness. The five stimuli chosen were a 1000-Hz pure tone, narrow band noise (700-1300 Hz band width), broad band noise (100-10,000 Hz band width), rock music, and babble speech, i.e., speech in which meaning is not discernible because several individuals are talking at once. Subjects were 30 normal young women (M = 19 yr.). During the auditory magnitude-estimation task for each of the five stimuli, a subject was instructed to assign numbers to stimulus presented in a randomly ordered series of nine sensation levels (10, 20, 30, 40, 50, 60, 70, 80, and 90 dB SL). Multivariate analysis of variance for repeated measures indicated there were no significant differences in the numerical responses of the subjects for the five stimuli. A possible explanation for these results is the presence of an underlying stabilizing factor (internal scaling mechanism) that allows adults to scale loudness consistently irrespective of the type of auditory stimulus.

Acoustic Stimulation↗

Does stimulus context affect loudness or only loudness judgments?

Marks (1988) reported that when equal-loudness matches were inferred from magnitude estimates of loudness for tones of two different frequencies, the matches were affected by changes in the stimulus intensity range at both frequencies. Marks interpreted these results as reflecting the operation of response biases in the subjects' estimates; that is, the effect of range was to alter subjects' judgments but not necessarily the perception of loudness itself. We investigated this effect by having subjects choose which of two tone pairs defined the larger loudness interval. By using tones of two frequencies, and varying their respective intensity ranges, we reproduced Marks' result in a procedure devoid of numerical responses. When the tones at one frequency are all soft, but the tones at the other frequency are not all soft, cross-frequency loudness matches are different from those obtained with other intensity range combinations. This suggests that stimulus range affects the perception of loudness in addition to whatever effects it may have on numerical judgments of loudness.

Adult↗

Sustained magnetic fields reveal separate sites for sound level and temporal regularity in human auditory cortex.

Magnetoencephalography was used to investigate the relationship between the sustained magnetic field in auditory cortex and the perception of periodic sounds. The response to regular and irregular click trains was measured at three sound intensities. Two separate sources were isolated adjacent to primary auditory cortex: One, located in lateral Heschl's gyrus, was particularly sensitive to regularity and largely insensitive to sound level. The second, located just posterior to the first in planum temporale, was particularly sensitive to sound level and largely insensitive to regularity. This double dissociation to the same stimuli indicates that the two sources represent separate mechanisms; the first would appear to be involved with pitch perception and the second with loudness. The delay of the offset of the sustained field was found to increase with interclick interval up to 200 ms at least, which suggests that the sustained field offset represents a sophisticated offset-monitoring mechanism rather than simply the cessation of stimulation.

Acoustic Stimulation↗

Limit cycles, noise, and chaos in hearing.

Based on insight obtained from a newly developed cochlea model, we argue that noise-driven limit cycles are the basic ingredient in the mammalian cochlea hearing process. For insect audition, we provide evidence in favor of the persistence of this principle. We emphasize the role of bifurcations for the emergence of broad-range sound perception, both in the frequency and amplitude domain, and indicate that this crucially depends on the correct coupling between limit cycles. We review the limit-cycle coupling universality, and outline how it can be used to encode information. Cortical noise is the microscopic basis for this encoding, whereas chaos emerges as the macroscopic expression of computation being done in the network. Large neuron firing variability is one possible consequence of the proposed mechanism that may apply to both vertebrate and insect hearing.

Animals↗

Perceptual scaling of synthesized musical timbres: common dimensions, specificities, and latent subject classes.

To study the perceptual structure of musical timbre and the effects of musical training, timbral dissimilarities of synthesized instrument sounds were rated by professional musicians, amateur musicians, and nonmusicians. The data were analyzed with an extended version of the multidimensional scaling algorithm CLASCAL (Winsberg & De Soete, 1993), which estimates the number of latent classes of subjects, the coordinates of each timbre on common Euclidean dimensions, a specificity value of unique attributes for each timbre, and a separate weight for each latent class on each of the common dimensions and the set of specificities. Five latent classes were found for a three-dimensional spatial model with specificities. Common dimensions were quantified psychophysically in terms of log-rise time, spectral centroid, and degree of spectral variation. The results further suggest that musical timbres possess specific attributes not accounted for by these shared perceptual dimensions. Weight patterns indicate that perceptual salience of dimensions and specificities varied across classes. A comparison of class structure with biographical factors associated with degree of musical training and activity was not clearly related to the class structure, though musicians gave more precise and coherent judgments than did non-musicians or amateurs. The model with latent classes and specificities gave a better fit to the data and made the acoustic correlates of the common dimensions more interpretable.

Adolescent↗

Interaction in the perceptual processing of interaural time and level differences.

Phillips and Hall [Psychophysical evidence for adaptation of central auditory processors for interaural differences in time and level, Hear. Res., 202 (2005) 188-199.] recently described the frequency-specific, selective adaptation of perceptual channels for interaural differences in level (ILD) and time (ITD). Psychometric functions for laterality based on ITD or ILD were obtained before and after exposure to adaptor tones of two frequencies presented alternately and highly lateralized to opposite sides. Following adaptation, points of perceived centrality (PPCs) were displaced towards the sides of the adaptor tones, and in opposite directions for the two frequencies. That is, laterality judgements showed a shift away from the adapted side, particularly for test cue values near the middle of the range. These data were congruent with a two-channel, opponent-process model of sound laterality coding. The present study used the same general paradigm to explore the independence of perceptual ITD and ILD processing. Psychometric functions for laterality based on ITD or ILD were obtained for each of two frequencies concurrently, before and after exposure to adaptor tones lateralized using the complementary cue. Once again, PPCs derived from the psychometric functions were displaced towards the sides of the adaptor tones, consistent with an opponent-process account of sound laterality coding. The size of the adaptation effect was at least as great as that described in the earlier study. Thus, a quarter cycle ITD adapting stimulus effected a 3 dB shift in the mean ILD-based PPC, and a 12 dB ILD adapting stimulus effected a 100 micros shift in the mean ITD-based PPC. These data offer new evidence concerning interaction in the processing of ITDs and ILDs.

Adaptation, Physiological↗

Development of directional responses to sounds in the rat (Rattus norvegicus).

The first of two experiments was carried out to examine the tendency of rat infants (13-20 days of age) to approach auditory stimulation. Tests were conducted in a circular maze with a central start area and eight response areas at the periphery. Stimuli were played back over a loudspeaker placed behind one of the eight response areas. Signals included species calls at high and low intensities. A control condition with blank tapes was also used. The subjects showed a clear tendency to approach the low-intensity playback of a species "social" vocalization but did not approach the other stimuli. The aim of the second experiment was to investigate the importance of binaural cues for localization. Rat infants were tested with one ear blocked, both ears blocked, or neither ear blocked. The effect of the ear plug(s) was to attenuate the sound approximately 10 dB. The results indicated that only the binaurally blocked and normal control subjects approached the sound source at above chance levels. The failure of subjects in the monaural group to approach the sound probably resulted from a disruption of binaural cues. The ability of rat infants to localize sounds and process binaural cues is discussed in relation to the onset of hearing and in terms of physiological response that are present early in ontogeny.

Aging↗

Auditory looming perception: influences on anticipatory judgments.

Several studies in the auditory-perception literature hint that listeners may be able to anticipate the time of arrival of an approaching sound source. Two experiments are reported in which listeners judged the time of arrival of an approaching car on the basis of various portions of its auditory signal. Subjects pressed a computer key to indicate when the car would have just passed them, assuming that the car maintained a constant approach velocity. A number of variables were tested including (a) the time between the offset of the signal and the virtual time of passage, (b) duration of the signal, and (c) feedback concerning judgment accuracy. Results indicate that increasing the time between signal offset and virtual time of passage decreases judgment accuracy whereas the actual duration of the signal had no significant effect. Feedback significantly improved performance overall.

Adult↗

Illusory changes in a sound source and outflow theory.

Two experiments, with a total of 220 Ss, were conducted to investigate the possibility of illusory movement of a sound source. In Experiment 1 intensity level (from 10 to 60 db SPL) and frequency of an auditory sound (from 1000 to 5000 Hz) were varied while the Ss head was stabilized with a head rest; in Experiment 2, intensity and frequency were also varied while the S's head was free to move. When head position was fixed, error signal variables such as intensity had no effect on the frequency of illusory direction changes of a sound source. However, when the head position was not fixed, increasing the intensity of the sound source significantly decreased the number of reported illusory direction changes. In addition, in both experiments, illusory changes of intensity were experienced by Ss, and increasing the intensity of the sound source also decreased this illusion. The results were interpreted in the context of an error signal and noise model of autokinetic effects, and the implications for the perception of auditory localization and movement of a sound source were discussed.

Auditory Perception↗

The effects of production and presentation level on the auditory distance perception of speech.

Although both perceived vocal effort and intensity are known to influence the perceived distance of speech, little is known about the processes listeners use to integrate these two parameters into a single estimate of talker distance. In this series of experiments, listeners judged the distances of prerecorded speech samples presented over headphones in a large open field. In the first experiment, virtual synthesis techniques were used to simulate speech signals produced by a live talker at distances ranging from 0.25 to 64 m. In the second experiment, listeners judged the apparent distances of speech stimuli produced over a 60-dB range of different vocal effort levels (production levels) and presented over a 34-dB range of different intensities (presentation levels). In the third experiment, the listeners judged the distances of time-reversed speech samples. The results indicate that production level and presentation level influence distance perception differently for each of three distinct categories of speech. When the stimulus was high-level voiced speech (produced above 66 dB SPL 1 m from the talker's mouth), the distance judgments doubled with each 8-dB increase in production level and each 12-dB decrease in presentation level. When the stimulus was low-level voiced speech (produced at or below 66 dB SPL at 1 m), the distance judgments doubled with each 15-dB increase in production level but were relatively insensitive to changes in presentation level at all but the highest intensity levels tested. When the stimulus was whispered speech, the distance judgments were unaffected by changes in production level and only decreased with increasing presentation level when the intensity of the stimulus exceeded 66 dB SPL. The distance judgments obtained in these experiments were consistent across a range of different talkers, listeners, and utterances, suggesting that voice-based distance cueing could provide a robust way to control the apparent distances of speech sounds in virtual audio displays.

Adult↗

Vibrotactile temporal masking: effects of multiple maskers.

Previous investigations of temporal masking effects in vibrotactile detection tasks have generally produced results suggesting considerable similarities in stimulus processing between the tactile system and the auditory system. Auditory presentation of combinations of maskers (e.g., two forward maskers) has yielded masking effects in excess of the level of masking predicted by a simple intensity sum of each masker's individual effect. This "additional masking" has led to predictions of compressive nonlinearities in auditory stimulus processing. In the present study, two experiments were conducted to investigate further temporal masking phenomena for the tactile system. In the first experiment vibrotactile temporal masking functions for single forward and backward maskers were generated to examine trade-offs among values of masker duration, masking intensity, and interstimulus interval to maintain constant detectability of a target. Results suggested that stimuli in very close temporal proximity to the target might follow somewhat different trading equations from those farther removed. Overall, results were consistent with previous findings of temporal integration in the tactile system, and support the notion of an energy integrating mechanism. In the second experiment, pairs of maskers were presented to determine whether additional masking effects occurred in vibrotactile detection. In contrast to findings for auditory presentation, in which all masker configurations generated additional masking, the tactile results showed substantial amounts of additional masking only for pairs of backward maskers. Several possible explanations for this results are evaluated, and results are discussed in terms of similarities and dissimilarities in auditory and tactile temporal processing.

Adult↗

Changes in voice level caused by several forms of altered feedback in fluent speakers and stutterers.

Speakers change the level of their voice when they listen to noise or hear their own speech amplified: When noise level is increased the voice becomes louder, whilst the response to speech amplification is a reduction of voice level. The question posed here is whether, when the level of various sounds concurrent with vocalisation is raised, the direction of the vocal level response is like that to the speaker's speech or like that to noise. Voice level was measured in response to speech, white noise, delayed auditory feedback, frequency-shifted speech, and noise created by an "Edinburgh masker". Selection of these sounds was governed by the role they have played in the explanation and treatment of stuttering. Fluent speakers and stutterers increased voice level when played delayed auditory feedback, the Edinburgh masker, or white noise; they reduced the level slightly in the remaining conditions. These results are used to assess auditory feedback monitoring accounts of the speech behavior of fluent speakers and stutterers, and some implications for the treatment of stuttering are pointed out.

Adult↗