Changes In Loudness Research Articles

Loudness change in response to dynamic acoustic intensity.

Three experiments investigate psychological, methodological, and domain-specific characteristics of loudness change in response to sounds that continuously increase in intensity (up-ramps), relative to sounds that decrease (down-ramps). Timbre (vowel, violin), layer (monotone, chord), and duration (1.8 s, 3.6 s) were manipulated in Experiment 1. Participants judged global loudness change between pairs of spectrally identical up-ramps and down-ramps. It was hypothesized that loudness change is overestimated in up-ramps, relative to down-ramps, using simple speech and musical stimuli. The hypothesis was supported and the proportion of up-ramp overestimation increased with stimulus duration. Experiment 2 investigated recency and a bias for end-levels by presenting paired dynamic stimuli with equivalent end-levels and steady-state controls. Experiment 3 used single stimulus presentations, removing artifacts associated with paired stimuli. Perceptual overestimation of loudness change is influenced by (1) intensity region of the dynamic stimulus; (2) differences in stimulus end-level; (3) order in which paired items are presented; and (4) duration of each item. When methodological artifacts are controlled, overestimation of loudness change in response to up-ramps remains. The relative influence of cognitive and sensory mechanisms is discussed.

Acoustic change processing in fetuses: a fMEG study

Event Abstract Back to Event Acoustic change processing in fetuses: a fMEG study Tamara Matuz1, Jana Muenssinger2*, Adrian Furdea1, R B Govindan3, Pamela Murphy3, Maureen Ware3, Jessica R. Temple3, Curtis L. Lowery3, Hari Eswaran3 and Hubert Preissl3, 4 1 University of Tuebingen, Institute of Medical Psychology and Behavioral Neurobiology, Germany 2 University of Tuebingen, Germany 3 University of Arkansas for Medical Sciences, Department of Obstetrics and Gynaecology, United States 4 University of Tuebingen, MEG and fMEG Center, Germany To date, fetal magnetoencephalographic studies have used pure or harmonic tones in standard oddball paradigms to assess central auditory processing and to investigate the basic cognitive function of sound discrimination. The aim of our study is to determine whether the sensitivity to spectral width and loudness of sound observed in newborns [1] is also present in fetuses. For this purpose, we have used white noise (WN) segments for the first time in fetal recordings. Ten fetuses (GA 33-36 weeks) were tested in two auditory oddball conditions, each consisting of a standard stimulus (probability of 0.8) and two infrequent deviant stimuli (0.1 probability each). WN (120 db), a 500Hz tone (120 db) and an attenuated WN (90 db) were used. In the first oddball condition (C1), a stream of attenuated WN (standard) was intermixed with the 500Hz tone (deviant 1) and the WN segment (deviant 2). In the second condition (C2), a stream of 500Hz tones (standard) was occasionally broken by attenuated WN (deviant 1) and WN (deviant 2). We compared the ERs elicited by the infrequent WN segments with those elicited by the infrequent attenuated WN (loudness change) and the infrequent 500Hz tones (spectral change). Detectable auditory ERs could be found in eight out of ten fetuses in C1 and in five out of ten in C2. ERs were determined based on visual inspection. Results show that amplitudes of ERs elicited by infrequent WN segments were not significantly different than of those elicited by the infrequent 500Hz tones (Z= -.70, p = 0.4; Wilcoxon Test). However, we found a trend toward significance regarding the difference between the amplitudes of ERs elicited by the WN segments and those elicited by attenuated WN (Z= -1.8, p = 0.08; Wilcoxon Test). These preliminary outcomes suggest that loudness change rather than spectral change influences the amplitudes of auditory ERs. Final results, including a statistical validation of determined ERs using a bootstrap approach are to be presented.

Perceptual Overestimation of Rising Intensity: Is Stimulus Continuity Necessary?

A "perceptual bias for rising intensity" (Neuhoff 1998, Nature 395 123-124) is not dependent on the continuous change of a dynamic, looming sound source. Thirty participants were presented with pairs of 500 ms steady-state sounds corresponding to onset and offset levels of previously used dynamic increasing- and decreasing-intensity stimuli. Independent variables, intensity-change direction (increasing, decreasing), intensity region (high: 70-90 dB SPL, low: 50-70 dB SPL), interstimulus interval (ISI) (0 s, 1.8 s, 3.6 s), and timbre (vowel, violin) were manipulated as a fully within-subjects design. The dependent variable was perceived loudness change between each stimulus item in a pair. It was hypothesised that (i) noncontinuous increases of intensity are overestimated in loudness change, relative to decreases, in both low-intensity and high-intensity regions; and (ii) perceptual overestimation does not occur when end-levels are balanced. The hypotheses were partially supported. At the high-intensity region, increasing stimuli were perceived to change more in loudness than decreasing-intensity stimuli. At the low-intensity region and under balanced end-level conditions, decreasing-intensity stimuli were perceived to change more in loudness than increasing-intensity stimuli. A significant direction x region interaction varied as a function of ISI. Methodological, sensory, and cognitive explanations for overestimation in certain circumstances are discussed.

Cross-modal facilitation in speech prosody

Speech prosody has traditionally been considered solely in terms of its auditory features, yet correlated visual features exist, such as head and eyebrow movements. This study investigated the extent to which visual prosodic features are able to affect the perception of the auditory features. Participants were presented with videos of a speaker pronouncing two words, with visual features of emphasis on one of these words. For each trial, participants saw one video where the two words were identical in both pitch and amplitude, and another video where there was a difference in either pitch or amplitude that was congruent or incongruent with the visual changes. Participants were asked to decide which video contained the sound difference. Thresholds were obtained for the congruent and incongruent videos, and for an auditory-alone condition. It was found that the congruent thresholds were better than the incongruent thresholds for both pitch and amplitude changes. Interestingly, the congruent thresholds for amplitude were better than for the auditory-alone condition, which implies that the visual features improve sensitivity to loudness changes. These results demonstrate that visual stimuli can affect auditory thresholds for changes in pitch and amplitude, and furthermore support the view that visual prosodic features enhance speech processing.

Análise perceptivo-auditiva de parâmetros vocais em cantores da noite do estilo musical brega da cidade do Recife

OBJETIVO: avaliar de forma perceptivo-auditiva a voz dos cantores da noite do estilo musical Brega da cidade do Recife. MÉTODOS: pesquisa realizada na clínica-escola do curso de Fonoaudiologia da Universidade Federal de Pernambuco e na emissora de TV Rede Estação canal 14, ambos localizados na cidade do Recife. Trata-se de estudo observacional, transversal e descritivo. Com anuência de 13 cantores, maiores de 18 anos, houve gravação da voz falada na emissão sustentada de vogais e durante a música "parabéns pra você"; na voz cantada realizou-se a gravação de trecho de música pertencente ao repertório do cantor. RESULTADOS: tempos de fonação reduzidos; modificações no pitch e loudness, comparando voz falada e cantada, ambos passando de adequados para, respectivamente, agudo e elevada; mudanças na ressonância, que era laringofaríngea e tornou-se equilibrada com compensação nasal. Houve manutenção do ataque vocal brusco; mudança do registro modal misto na voz habitual para o modal cabeça na voz profissional; predominância da qualidade vocal clara na voz falada e padrões adequados para modulação, projeção e articulação na voz cantada. CONCLUSÃO: os cantores da noite do estilo musical Brega da cidade do Recife apresentaram tempos de fonação reduzidos e tiveram, da voz falada para a voz cantada, mudanças no pitch, loudness e ressonância e manutenção das características vocais para ataque e registro. A qualidade vocal clara na voz falada foi predominante, assim como a modulação adequada, boa projeção e articulação precisa estavam entre os padrões vocais mais frequentes na voz cantada.

Looming sounds as warning signals: The function of motion cues

Sounds with increasing intensity can act as intrinsic warning cues by signalling that the sound source is approaching. However, intensity change is not always the dominant motion cue to a moving sound, and the effects of simple rising intensity sounds versus sounds with full three dimensional motion cues have not yet been directly compared. Here, we examined skin conductance responses, phasic alertness, and perceptual and explicit emotional ratings in response to approaching and receding sounds characterised either by full motion cues or by intensity change only. We found a stronger approach/recede effect in sounds with full motion cues for skin conductance response amplitude, suggesting sustained mobilisation of resources due to their greater saliency. Otherwise, the approach/recede effect was comparable in sounds with and without full motion cues. Overall, approaching sounds elicited greater skin conductance responses and phasic alertness, and loudness change was estimated higher. Also, they were rated as more unpleasant, potent, arousing and intense, and the probability of such sounds to signal a salient event or threat was rated higher. Several of these effects were modulated by sex. In summary, this study supports the suggestion that intensity change is the dominant motion cue mediating the effects of approaching sound sources, thus clarifying the interpretation of previous studies using such stimuli. Explicit emotional appraisal of such sounds shows a strong directional asymmetry and thus may reflect their implicit warning properties.

Investigations Into the Velocity and Distance Perception of Moving Sound Sources

Temporal loudness changes, binaural cues and Doppler shift can all influence distance perception of moving sound sources. This article will analyze different auditory distance perception cues of moving sound sources. In psychoacoustic experiments, the subjects were presented with dichotic and diotic stimuli of a set of real-life recordings taken from a passing passenger car and then asked to determine the velocity of the object and its minimal distance from the listener. The results of the listening experiments allow us to separate monaural distance perception cues from binaural ones, and thus show that binaural cues contribute significantly to the perception of velocity. For short distances and high velocities, the presentation of binaural cues causes a decrease in the perceived velocity while for long distances and low velocities this causes a clear increase. By estimating the minimal distance from the passing object, one observes a significant difference between dichotic and diotic presentation, which can be explained by an increased loudness of dichotic stimuli due to the binaural masking level difference (BMLD). Furthermore, it is shown that the main parameter for distance determination is the maximum sound pressure level at the listener's position. However, dynamic cues (change of sound pressure level over time, Doppler shift) are of considerable importance for the plausibility of the auditory scene.

Event-related oscillations in mice: Effects of stimulus characteristics

Event-related oscillations (EROs) are rhythmic changes that are evoked by sensory and/or cognitive processes that influence the dynamics of the EEG. EROs are estimated by a decomposition of the EEG signal into phase and magnitude information for a range of frequencies and then changes in those frequencies are characterized over a millisecond time scale with respect to task events. EROs have been demonstrated to be sensitive measures of both normal and abnormal cognitive functioning in humans but have not been fully described in mice. The results of these studies demonstrate that EROs can be generated in cortical sites in mice in the delta, theta, alpha/beta frequency ranges in response to auditory stimuli. Oscillations in the 7.5–40Hz frequencies were significantly affected in the 0–50ms time range in response to differences in tone frequency. Whereas, changes in tone loudness produced changes in oscillations in the 7.5–40Hz frequencies in the 350–800ms range. No significant changes in EROs were found to differences in tone probability. These studies suggest that EROs are an electrophysiological assay sensitive to tone characteristics and as such may be suitable for the exploration of the effects of genetic or neuropharmacological manipulations on neurosensory processing in mice.

Voice Boot Camp

Voice Boot Camp

Head, Neck, and Eye Movements That Modulate Tinnitus

Recent functional brain imaging studies in humans suggest that the neural generator(s) for tinnitus may reside in the central nervous system and involve both auditory as well as nonauditory centers. The contribution of nonauditory centers in the pathogenesis and regulation of tinnitus is reinforced by studies showing that many patients have somatic tinnitus whereby movements and manipulations of the eyes, head, neck, jaw, and shoulder can modulate the loudness and pitch of their tinnitus. In most cases, the maneuvers lead to increases in tinnitus loudness or pitch rather than decreases. Our results indicate that most tinnitus patients experience only a modest change in loudness or pitch when performing these maneuvers. However, some patients report that these maneuvers significantly modulate the loudness or pitch, sometimes by a factor of 2 to 3. The high prevalence of somatic tinnitus serves to illustrate the complex multimodal interactions that exist between the auditory pathway and other sensory-motor systems innervating the head, neck, shoulders, and eyes.

Loudness of impulsive sounds as a function of duration: a parametric study of the effect of level and frequency

Loudness of brief signals increases when signal duration increases up to about 100 ms, this increase is called temporal summation. The question examined in this study is to determine how loudness change as a function of duration. Literature shows different results that lead to different conclusions: when duration increases (i) the loudness increases in direct proportion to energy (intensity x duration); (ii) the loudness increases faster than energy; (iii) the loudness increases slower than energy. We have shown, in previous experiments, that loudness change with duration can follow either (i) or (ii) depending on signal level. The present study provides a parametric examination of this question. Loudness was measured for signals whose energy was kept constant while the duration was varied. The parameters of the experiment were the signal frequency and level. The results allow us to explain part of the discrepancies found in literature. Moreover, the results of this study are used into a model of impulsive sounds that calculate with a good precision the loudness of environnemental short‐duration sounds.

Acoustic flexibility in singing birds under noisy urban conditions

Birds rely on song for defending a territory and attracting a mate. More and more breeding areas are affected by human activities and anthropogenic noise has become almost omnipresent. Consequently, song function in and around cities, and alongside highways, train tracks and airports, is increasingly hampered by noise interference. Several counter strategies in producing sounds, related to changes in loudness, pitch, and timing, can help out under these noisy urban conditions. Observational data have yielded several interesting patterns which show remarkable singing flexibility in different species that are typically common in cities. Here I present data for a new species, the chiffchaff (Phylloscopus collybita) showing spectral and temporal adaptation which reduces masking alongside a highway in the Netherlands. Furthermore, experimental field data reveal for the first time that this species is able to adjust immediately to exposure to highway noise via artificial playback in quiet territories. Acoustic flexibility may be key to efficient use of the 'left-over acoustic space' and may determine whether individual birds can maintain their territory and breed successfully. Variation in flexibility among species may explain which birds will remain widespread in our noisy world and which will be pushed back into 'silent' habitat pockets.

Loudness asymmetry ratings between accelerating and decelerating car sounds

Loudness change has been studied for tones with linearly varying levels revealing an asymmetry depending on the direction of change (increasing vs. decreasing) and the range of levels (high vs. low). Different assumptions were proposed to explain this asymmetry in favour of linearly increasing sounds. Teghtsoonian et al. (2005) and, more recently, Susini et al. (2006) explain that loudness of an increasing sound is influenced by the end level. Neuhoff (1999) describes this result by a survival advantage for detecting an approaching sound source. Whatever the assumption is, the results show that loudness judgments for abstract sounds (1000‐Hz tones) and synthetic vowel sounds were significantly higher for increasing ramps. Those results are compared here with continuous and global ratings obtained on everyday sounds such as accelerating and decelerating car sounds with a same duration (43 s), but with different temporal functions and range of levels. Global loudness judgments made after the end of the sound are significantly higher for accelerating than decelerating car sounds, but are judged on average similar using continuous judgments. In addition, an increase in the speed (acceleration) is evaluated primarily in terms of its level at the end. These results confirm the previous studies.

Magnitude judgments of loudness change for discrete, dynamic, and hybrid stimuli

Recent investigations of loudness change across dynamically varying stimuli have identified differences between increasing versus decreasing power that depends upon stimulus complexity and intensity range [e.g., Canévet, Acustica, 62, 2136‐2142 (1986); Neuhoff, Nature, 395(6698), 123‐124, (Sep 1998)]. Some explanations of these findings are based upon known psychophysical effects [Teghtsoonian, Teghtsoonian & Canévet, Perception & Psychophysics, 67(4), 699‐712 (2005)], whereas others posit qualitative differences in the perception of discrete laboratory and dynamic natural sound structures (Neuhoff, 1998). For discrete, static stimuli, the relationship between loudness and power is dependant upon a number of factors, including frequency, intensity range, perceptual anchoring, temporal order, and integration of power across time. The current investigation examines listener perception of loudness for sound structures that vary systematically from discrete to dynamic changes in power, allowing evaluation of the contributions of static versus dynamic change, as well as other factors in the perception of loudness change within complex stimuli. Relevant methodology, as well as commonalities and differences with predictions of traditional psychophysics, are discussed.

A Controlled Single-Case Treatment of Severe Long-Term Selective Mutism in a Child With Mental Retardation

The aim of the present study was to demonstrate the efficacy of combining two operant learning procedures—shaping and fading—for treating selective mutism. The participant was a 12-year-old boy with mental retardation presenting a severe long-term selective mutism. The treatment was aimed at increasing the loudness of his vocalizations in an increasingly social milieu. The treatment was conducted over the course of about 20 weeks, with four 15-minute sessions per week. A gradual increase in speech loudness was observed. Data indicated a close correspondence between the changes in speech loudness and the criteria for reinforcement successively applied by the therapist, thereby confirming the causal link between the child's progress and the changes in reinforcement contingencies. In addition, good generalization was noted during the stimulus fading phase. Six-month follow up showed that loudness of verbalizations was still satisfactory in the classroom despite a change of school and peer group. The impressive improvement of the child's verbal behavior shows that the implementation of a treatment package including both shaping and stimulus fading is a worthwhile therapeutic option, even in the case of severe long-term selective mutism associated with mental retardation.

Alternative pulse shapes in electrical hearing

Cochlear implants (CIs) stimulate the auditory nerve with trains of symmetric biphasic (BI) pulses. We review studies showing that more efficient stimulation can be achieved by modifying these pulses by (1) increasing the inter-phase gap (IPG) between the two phases of each pulse, thereby delaying the recovery of charge, (2) increasing the duration and decreasing the amplitude of one phase - so-called "pseudomonophasic (PS)" waveforms, and (3) combining the pseudomonophasic stimulus with an IPG in a "delayed pseudomonophasic" waveform (PS_IPG). These efficiency gains, measured using changes in threshold and loudness, occur at a wide range of pulse rates, including those commonly used in current CI systems. In monopolar mode, dynamic ranges are larger for PS and for long-IPG pulse shapes than for BI pulses, but this increase in DR is not accompanied by a higher number of discriminable loudness steps, and hence, in a better coding of loudness. Moreover, waveforms with relatively short and long interphase gaps do not yield different patterns of excitation despite the relatively large differences in threshold. Two important findings are that, contrary to data obtained in animal experiments, anodic currents are more effective than cathodic stimulation for human CI patients and that the thresholds decrease with increases in IPG over a much longer time course (more than 3 ms) than for animals. In this review it is discussed how these alternative pulse shapes may be beneficial in terms of reducing power consumption and channel interactions, which issues remain to be addressed, and how models contribute to guiding our research.

The mid-difference hump in forward-masked intensity discrimination

Forward-masked intensity-difference limens (DLs) for pure-tone standards presented at low, medium, and high levels were obtained for a wide range of masker-standard level differences. At a standard level of 25 dB SPL, the masker had a significant effect on intensity resolution, and the data showed a mid-difference hump: The DL elevation was greater at intermediate than at large masker-standard level differences. These results support the hypothesis that the effect of a forward masker on intensity resolution is modulated by the similarity between the masker and the standard. For a given masker-standard level difference, the effect of the masker on the DL was larger for a 55-dB SPL than for the 25-dB SPL standard, providing new support for a midlevel hump. To examine whether the masker-induced DL elevations are related to masker-induced loudness changes [R. P. Carlyon and H. A. Beveridge, J. Acoust. Soc. Am. 93, 2886-2895 (1993)], the effect of the masker on target loudness was measured for the same listeners. Loudness enhancement followed a mid-difference hump pattern at both the low and the intermediate target level. The correlation between loudness changes and DL elevations was significant, but several aspects of the data are incompatible with the predicted one-on-one relation between the two effects.

Psychoacoustical correlates of musically induced chills

Music listening is often accompanied by the experience of emotions, sometimes even by so-called “strong experiences of music” (SEMs). SEMs can include such pleasurable reactions as shivers down the spine or goose pimples, which are referred to as “chills”. In the present study, the role of psychoacoustical features was investigated with respect to the experience of chills. Psychoacoustical parameters of short musical segments (total duration: 20 s), characterized as chill- inducing, were analyzed and compared with musical excerpts which did not induce chill responses. A significant increase of loudness in the frequency range between 8 and 18 Bark (920–4400 Hz) was found in those excerpts for which chills were reported. Frequency-dependent changes of loudness seem to play an important role in the induction of chills.

Loudness dependence of evoked dipole source activity during acute serotonin challenge in females

Direct challenge of cortical serotonergic (5-hydroxytryptamine, 5-HT) availability by tryptophan depletion test (TDT) was used to assess the hypothesized inverse relationship between central 5-HT function and loudness dependence of auditory evoked potentials (LDAEPs). Gender must be taken into particular account here, since there are gender differences in 5-HT brain synthesis, with women reacting more strongly to TDT. In a double-blind, controlled cross-over study, 16 healthy females were ingested two highly concentrated amino acid mixtures with (+TRP) or without TRP (-TRP). While monitoring TRP levels and mood states, the AEP of different loudness stimuli were recorded, followed by dipole source analysis. Under the -TRP condition, free plasma TRP levels decreased by 81.10% (+/-5.14). Most of the loudness change rates of the relevant N1/P2 tangential dipole activities were significantly increased under -TRP, but calculated LDAEP did not differ significantly between treatments. LDAEP and states of mood were not correlated. Despite strong TRP depletion, the results did not reach sufficient evidence that LDAEP is a valid biological marker of central 5-HT activity in females when using TDT. This agrees with the literature and supports the view that LDAEP indicates predominantly biological vulnerability in predisposed individuals.

Mechanisms Responsible for Differences in Perceived Duration for Rising-Intensity and Falling-Intensity Sounds

Sounds that are equivalent in all aspects except for their temporal envelope are perceived differently. Sounds with rising temporal envelopes are perceived as louder, longer, and show a greater change in loudness throughout their duration than sounds with falling temporal envelopes. Stecker and Hafter (2000) proposed that participants ignore the decay portion of sounds with falling temporal envelopes to account for observed loudness differences, but there is no empirical evidence support this hypothesis. To test this idea, two duration-matching experiments were performed. One experiment used broadband noise and the other natural stimuli. Different groups of participants were given different instruction sets asking them to (1) simply match the duration or (2) include all aspects of the sounds. Both experiments produced the same result. The first instruction set, which represented participants' natural biases, yielded shorter subjective durations for sounds with falling temporal envelopes than for sounds with rising temporal envelopes. By contrast, asking participants to include all aspects of the sounds significantly reduced the size of the asymmetry in subjective duration, a result that supports Stecker and Hafter's hypothesis. This segregation of the stimulus at the perceptual level is consistent with observed asymmetries in loudness change and overall loudness for sounds with rising and falling temporal envelopes, but it does not account for the entire effect. The remaining portion of the effect, after considering biases due to instructions, is not likely a result of adaptation but could be associated with persistence. The amount of persistence was inferred from behavioral masking data obtained for these sounds.