Loudness Differences Research Articles

Binaural loudness summation by cochlear implant users.

The loudness summation in people with bilateral and unilateral cochlear implants (CIs) was investigated. The stimuli were 1/3‐octave bands of noise centered at frequencies of 0.25, 1, and 4 kHz presented frontally from a loudspeaker in an ascending or random sequence of level. Subjects rated different intensity levels between the threshold of hearing and level of discomfort on scales from 0 to 100. Eight intensity levels were used for normally hearing subjects who served as a control group. For the CI users, results showed difference in loudness between monaural and binaural conditions with substantial amount of binaural loudness summation. The shape of the intensity‐loudness function varied between monaural and binaural conditions, depending on the listener. The power function of control group exhibited an exponent of near 0.5. In binaural condition, stimuli of the same sound pressure level were about 1.8 louder than in monaural condition. For 0.25‐ and 4‐kHz bands of noise, no consistent differences bet...

Efficacy and adverse effects of Xanthane nasal solution as treatment of primary snoring

Background: Habitual snoring is a disturbing social problem. Surgical treatments have succeeded in reducing obstructions in some patients, but carry significant risks and almost always result in significant postoperative pain. Xanthane nasal solution is a nasal spray that may be beneficial in reduction of vibratory sound from the soft palate, uvula and the tongue base. It has offered patients some relief, but effectiveness is doubtful. Objective: To study the efficacy and adverse effects of Xanthane nasal solution in primary snoring. Methods: A randomized, double-blinded, placebo-controlled, cross-over study was done. Fifty-nine primary snoring patients diagnosed by polysomnography were enrolled. Loudness of snoring was assessed by their regular bed partners using visual analog scales. Adverse effects were also assessed. ANOVA for cross-over design and Friedman test were used for statistical analysis. Results: Fifty-one subjects were able to follow the protocol until the end of the study. Eight subjects dropped out. There was no significant difference in loudness of snoring between xanthane nasal solution and placebo (p = 0.06; 95 % confidence interval = -9.1 to 0.1). Adverse effects were not different between the two groups. Conclusion: This study showed no beneficial effects of xanthane nasal solution in primary snoring patients. There was no adverse reaction.

Processing intensity at rapid rates: Evidence from auditory evoked potentials in 9–11-year-old children

The ability to understand speech requires processing of rapidly changing acoustic information. Much more is known about processing the rapid spectro-temporal properties of speech than is known about processing of intensity, even though intensity is a fundamental cue for accurate speech perception. The purpose for the current study was to characterize, in 9-11-year-old typically language-developing children, the auditory event-related brain potentials elicited by different tone intensities when presented in complex environments (i.e., varying in frequency and intensity) at rapid rates. Pure tones of four different intensity levels (66, 74, 78, and 86dB SPL) and five different stimulus frequencies were presented at a stimulus rate of 10Hz. The latency and amplitude of the auditory event-related brain potentials were measured. At this fast rate, a positive (P1) followed by a negative component was elicited. The lowest intensity sound elicited the lowest P1 amplitude and the highest intensity sound elicited the highest P1 amplitude. The P1 elicited by the two middle tone intensities had amplitudes that fell between the lowest and highest amplitudes but they were not significantly different from each other. The negative component following the P1 was unaffected by intensity variation. Intensity variation of sounds presented in a complex environment at a rapid rate modulated only the amplitude of the earliest obligatory auditory component (P1), consistent with our previous studies in which only the P1 could follow the rapid stimulation rate. P1 amplitude changes reflected the relative differences among the sounds, not the absolute differences in loudness among the sounds presented together in the sequence. The results suggest that the environment, or context, within which rapid sounds occur, influences the relative amplitude of the P1 in children.

Just noticeable differences of loudness and sharpness for earth moving machines

This paper describes some results of a research concerning the improvement of the noise climate at the operator station of construction machines during real working conditions. Binaural noise signals were previously recorded and then used in subjective listening tests aimed at identifying the set of acoustic and psychoacoustic parameters which affect the auditory perception of these signals with respect to the annoyance sensation. Results showed that loudness and sharpness are the parameters best correlated to the annoyance. In order to verify the efficacy of some noise control solutions in improving the operator comfort conditions, the next necessary step is to build a specific metrics able to show the minimum differences in these parameters which are subjectively perceived. This paper describes the results of specific listening tests carried out in order to evaluate the differential thresholds of loudness and sharpness by the Method of Limits. The test was repeated at two different signal presentation levels. The loudness value of each original stimulus was varied by interval steps of 0,3 sone, while the Sharpness by interval steps of 0,02 acum. At this moment in time, the data analysis is still in progress and the ultimate results will be presented in the manuscript.

Influence of vehicle color on loudness judgments

This experiment investigates the effect of images of differently colored sports cars on the loudness of a simultaneously perceived car sound. Still images of a sports car, colored in red, light green, blue, and dark green, were displayed to subjects during a magnitude estimation task. The sound of an accelerating sports car was used as a stimulus. Statistical analysis suggests that the color of the visual stimulus may have a small influence on loudness judgments. The observed loudness differences are generally equivalent to a change in sound level of about 1 dB, with maximum individual differences of up to 3 dB.

Are absolute thresholds and loudness judgements influenced by different colours

Previous experiments showed that images of differently colored trains and sports cars can influence the loudness ratings given by subjects via free magnitude estimation. Red vehicles caused subjects to rate the loudness of simultaneously presented train or car sounds higher relative to green vehicles. To investigate whether these loudness differences correspond to shifts in absolute threshold, subject's threshold in quiet was measured via Békésy-tracking while viewing red, green, and neutral color patches. Also, the influence of color on the loudness of broadband noise was measured using a method of adjustment, in which subjects had to adjust the level of a test sound until it was perceived as loud as a reference sound. In both cases, no influence of color on either absolute threshold or loudness perception measured via adjustment could be found. These results support the hypothesis that, compared to previously used methods like magnitude estimation, methods that require subjects to concentrate on the auditory stimulus do not seem to be as applicable for measurements of audio-visual interactions.

Perception of suprathreshold amplitude modulation and intensity increments: Weber’s law revisited

The perceived strength of intensity fluctuations evoked by suprathreshold sinusoidal amplitude modulation (AM) and the perceived size of intensity increments were compared across levels of a wideband noise and a 1-kHz tone. For the 1-kHz tone, the comparisons were made in quiet and in a high-pass noise. The data indicate that suprathreshold modulation depths and intensity increments, perceived as equivalent across levels, follow a pattern resembling Weber's law for noise and the "near miss" to Weber's law for a tone. The effect of a high-pass noise was largely consistent with that observed for AM and increment detection. The data suggest that Weber's law is not a direct consequence of the dependence of internal noise on stimulus level, as suggested by multiplicative internal noise models. Equal loudness ratios and equal loudness differences (computed using loudness for the stationary portions before and after the increment) accounted for the increment-matching data for noise and for the tone, respectively, but neither measure predicted the results for both types of stimuli. Predictions based on log-transformed excitation patterns and predictions using an equal number of intensity just-noticeable differences were in qualitative, but not quantitative, agreement with the data.

Heparin Induced Extracorporeal LDL Precipitation (H.E.L.P.) in Treatment of Tinnitus: A Randomised, Multicentre Trial

Background: At the beginning, cochlear tinnitus seems to arise from a dysfunction of cochlear outer hair cells. Similar to other inner ear disorders a disturbance of cochlear microcirculation is one of the most frequently discussed reasons. Animal studies and clinical evidence show a negative effect of high cholesterol and fibrinogen on hearing function. Acutely lowering serum LDL and fibrinogen by means of LDL and fibrinogen apheresis increases cochlear blood flow and has been proven to be effective in treatment of idiopathic sudden sensorineural hearing loss. Therefore we aimed to determine whether acute reduction of plasma fibrinogen and serum LDL is effective for treatment of subacute tinnitus. Methods: Between January, 2004 and December, 2006 we included patients of 18 through 80 years of age suffering from subacute cochlear tinnitus between 3 to 12 months on one or both ears and having serum LDL-cholesterol between 130 and 190 mg/dl. Tinnitus was evaluated using a standardised questionnaire designed by Goebel and Hiller. Patients meeting inclusion criteria were provided with the HMG-CoA reductase inhibitor simvastatin 40 mg once daily for 3 months. This procedure was done due to ethical reasons to reduce cholesterol and LDL non invasively in a first step. After 3 months tinnitus was re-evaluated and patients were excluded from the study if severity fell by more than 20 on the tinnitus score. 27 included participants were randomly assigned in a one to one ratio either to triple fibrinogen/LDL apheresis or triple sham therapy. Differences between tinnitus score on the day of randomisation and after 12 weeks were used as main outcome measure. Development of tinnitus score after every treatment, differences in loudness and frequency of tinnitus (masking and matching) after every treatment and after 12 weeks and the development of hearing thresholds after 12 weeks were used as secondary outcome measures. Findings: Main outcome measure tinnitus score 12 weeks after first therapy showed no significant differences between the groups. Though, there was a strong tendency towards an relieve of tinnitus in the apheresis group (p = 0.069 for the difference of the baseline value and the 12 weeks value between apheresis vs sham-therapy). Neither pure tone thresholds after 12 weeks, nor tinnitus masking and matching after every therapy and after 12 weeks showed significant differences between the groups. Conclusions: In our study, all patients suffered from subacute tinnitus and tinnitus score was stable or slightly worse in the placebo group over time. The improvement of tinnitus score in the apheresis group – although not statistically significant – is therefore a remarkable observation. For a more conclusive evaluation of this observation further studies with a larger number of patients should be conducted.

Experimental studies on annoyance caused by noises from trams and buses

Acute annoyance due to noise from trams and buses was ascertained and compared in two experimental studies. First, 22 healthy young persons (19–22 years) using a standardised scale, rated their annoyance caused by noise from trams, buses and trucks, which were each presented at seven sound levels. The noise of a tram was judged to be equally annoying as the noise of a bus with a 3 dB lower level, which corresponds to the calculated loudness difference. The noises of a tram and of a bus were superimposed onto a 2-h realistic road traffic scenario in the second study. This study was conducted with 60 healthy young persons (18–31 years). Twenty participants were each exposed either to the scenario with the tram or the bus ( L AeqT=55 dBA) or to a control condition ( L AeqT=43.6 dBA) while working on different mental tasks. Performance data did not differentiate between the noise conditions, but the participants were again less annoyed by the scenario with the tram, suggesting a possible bonus for the tram. This assumption has to be verified in future studies. The fact that calculated loudness could predict annoyance in the psychoacoustic tests and this annoyance due to the same noises presented in complex scenarios might indicate the possibility of a more economical approach, at least to noises between which loudness differs greatly.

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.

Differences in loudness of positive and negative Schroeder-phase tone complexes as a function of the fundamental frequency

Tone complexes with positive (m+) and negative (m-) Schroeder phase show large differences in masking efficiency. This study investigated whether the different phase characteristics also affect loudness. Loudness matches between m+ and m- complexes were measured as a function of (1) the fundamental frequency (f0) for different frequency bands in normal-hearing and hearing-impaired subjects, and (2) intensity level in normal-hearing subjects. In normal-hearing subjects, the level of the m+ stimulus was up to 10 dB higher than that of the corresponding m- stimulus at the point of equal loudness. The largest differences in loudness were found for levels between 20 and 60 dB SL. In hearing-impaired listeners, the difference was reduced, indicating the relevance of active cochlear mechanisms. Loudness matches of m+ and m- stimuli to a common noise reference (experiment 3) showed differences as a function of f0 that were in line with direct comparisons from experiment 1 and indicated additionally that the effect is mainly due to the specific internal processing of m+. The findings are roughly consistent with studies pertaining to masking efficiency and can probably not be explained by current loudness models, supporting the need for incorporating more realistic cochlea simulations in future loudness models.

Perceptual measurement of sound level differences between TV programs and advertisements

In order to investigate loudness difference between TV program materials and advertisements (CMs) inserted in the materials, sound levels of CMs broadcast in five terrestrial broadcasting stations throughout a day were quantitatively measured and a perceptual experiment was performed. The averaged sound levels (ASLs) and the standard deviations (SDs) of 4262 CMs were concentrated on −7 dB and 5 dB, respectively. Next, three types of CMs with different ASLs and SDs were used to the perceptual experiment. These ASLs and SDs were (−5.1 and 1.8 dB for CM-1), (−7.1 and 4.9 dB for CM-2), (−14.2 and 10.1 dB for CM-3), respectively. The reference sound as a main program material was speech uttered by a NHK female announcer with duration of 10 s. The ASL and the SD were −6.5 and 10.1 dB, respectively. The transformed up-down method was used for 12 observers with normal hearing. The results show that all CMs were perceived at least 3 to 5 dB louder than the reference for a half of the observers. These results show that there is large perceptual discrepancy between CMs and the main program materials. [Work supported by The Okawa Foundation.]

Prominence in Tamil

This paper investigates whether or not there are phonetic correlates of prominence at the word level in Tamil that can be associated with word-initial stress. There is no lexically distinctive stress but there are indications in previous work – based on impressionistic judgements and experimental evidence of vowel reduction patterns – that word-initial syllables may be prominent. Sets of words containing segmentally identical syllables in different positions within the word, e.g. [nariku], [kanavu] and [w o:dina] were recorded by five speakers in a carrier phrase. The prosodic properties of the test syllables were compared to establish whether syllable position had a significant effect. No consistent results were found for either duration or loudness: their role at the word level in Tamil seems to be confined to marking intrinsic segmental and quantitative distinctions. Significant differences in F0 related to syllable position would be consistent with initial syllables bearing abstract word-level prominence. This would be marked primarily through the association of phrasal pitch accents, unaccompanied by independent differences of loudness or robust durational effects.

Soundscape measurement and analysis

Soundscapes typically include a variety of sources, with individual and collective attributes (level, spectral structure, time structure, and perceived characteristics such as loudness, sharpness, fluctuation, and roughness). Relevant sound sources impinge on listeners from multiple directions and distances. Examples will be given of large differences between conventional and psychoacoustic values as a function of distance, and of multi‐source summations. As an example, the subjective loudness difference for sound incidence over a small versus large solid angle for a constant sound pressure level and spectrum is known. Individual‐source‐relevant information, important in context, may be unrecognized unless spatial hearing is included in soundscape assessment. A demonstration of binaural versus monaural soundscape data acquisition, and subsequent analysis by both conventional and psychoacoustic measures considering human perception including time dependency, will be given. Evidence will be presented for considering human hearing not only in the analysis, but also in the acquisition.

다수의 음원을 사용한 공간의 소리 제어 방법론

Spatial control of sound is essential to deliver better sound to the listener's position in space. As it can be experienced in many listening environments. the quality of sound can not be manifested over every Position in a hall. This motivates us to control sound in a region we select. The primary focus of the developed method has to do with the brightness and contrast of acoustic image in space. In particular, the acoustic brightness control seeks a way to increase loudness of sound over a chosen area, and the contrast control aims to enhance loudness difference between two neighboring regions. This enables us to make two different kinds of zone - the zone of quiet and the zone of loud sound - at the same time. The other perspective of this study is on the direction of sound. It is shown that we can control the direction of perceived sound source by focusing acoustic energy in wavenumber domain. To begin with, the proposed approaches are formulated for pure-tone case. Then the control methods are extended to a more general case, where the excitation signal has broadband spectrum. In order to control the broadband signal in time domain, an inverse filter design problem is defined and solved in frequency domain. Numerical and experimental results obtained in various conditions certainly validate that the acoustic brightness, acoustic contrast, direction of wave front can be manipulated for some finite region in space and time.

Differences in loudness of tone complexes with positive and negative Schroeder phase

Tone complexes with positive (m+) and negative Schroeder phase (m−) have an identical long-term spectrum, the same temporal envelope but are inverted in time. They show large differences in masking efficiency most probably being related to a different cochlear representation. The current study investigates to which extent loudness perception is affected similarly by the different phase characteristic of m+/m− stimuli. Therefore, the loudness of m+/m− stimuli (1.6 octave bandwidth) was matched in seven normal hearing and three hearing impaired subjects. In the first experiment the fundamental frequency f0 of the tone complexes was varied from 2–1536 Hz for different center frequencies at a soft level of the reference signal (m−). In normal hearing subjects the m+ stimuli need a 6 dB higher level to be perceived as equally loud as the respective m− stimuli (for f0 in the range of 24–96 Hz). In the second experiment the difference in loudness of m+/m− was investigated as function of the of the reference-stimulus level (5–80 dB SL) at a center frequency of 2660 Hz and f0 at 48 Hz. The largest differences in loudness were found for levels between 40–60 dB, clearly reduced for higher and lower levels of the reference stimulus.

The relationship between three auditory inspection time tasks and general intelligence

Three inspection-time tasks measuring the amount of time required to discriminate differences in pitch, loudness and phase were administered alongside the Multidimensional Ability Battery and Raven’s Advanced Progressive Matrices to 75 undergraduate students. The auditory tasks were administered adaptively, and thresholds were estimated by fitting a logistic function to each set of data. After correcting for restriction of range the three thresholds intercorrelated significantly, and correlated between −0.33 and −0.68 with scores on the ability tests. A composite auditory inspection time score correlated between −0.35 and −0.42 with the ability measures (−0.50 to −0.54 after correction). Although strategy-use enhanced performance on the pitch inspection-time task, strategy use was unrelated to intelligence and did not mediate the correlation between inspection time and intelligence.

A scale value for the balance inside a historical opera house

In the framework of opera house acoustics, the term "balance" refers to the acoustical competition between the singer on the stage and the orchestra in the pit. The mechanism allowing the operatic singers to be heard over the orchestra has to do with their skill in enhancing the vocal emission by a peculiar use of the formant frequencies. This vital factor is sensed by the listeners and, apart from the obvious sound power ratio of the stage and the pit sources, is the main cue that helps to formulate a subjective impression of the balance. To achieve its objective qualification, two calibrated sound sources can be placed on the stage and in the pit, respectively, and their sound level difference is measured at the listeners' seats. The scope of this work is to investigate the relationship between the subjective impression and the objective indicator of the balance and to develop a scale value for the parameter in the case of a historical opera house. For this scope a set of acoustical data from the Teatro Comunale in Ferrara will be used to create synthetic sound fields with controlled conditions of the balance between the stage and the pit. This methodology employs an anechoic piece for soprano (with piano accompaniment) and is implemented in a dead room equipped with an acoustical rendering system. The sound fields are used to investigate the appropriate balance values by means of listening tests. The results of the scaling exercise show that a suitable range of values can be extracted and that the sound from the stage and the pit is perceived as balanced when the loudness difference between the two is comprised within -2.0 dBA and +2.3 dBA.

The effect of task on determination of habitual loudness

Summary The purpose of this study was to investigate if there is an effect of task on determination of habitual loudness. Four tasks commonly used to elicit habitual loudness were compared (automatic speech, elicited speech, spontaneous speech, and reading aloud). Participants were adult female speakers (N = 30) with normal voice. A one-way analysis of variance (ANOVA) revealed a statistically significant ( p < 0.05) effect of task, with post-hoc analyses indicating that there was a statistically significant difference in habitual loudness elicited via automatic versus spontaneous speech ( p < 0.05), and automatic speech versus reading aloud ( p < 0.001). The issue of how habitual loudness is defined is considered. Implications of the use of one task for determination of habitual loudness are discussed, as is the possibility of a task effect on determination of other clinically useful vocal parameters.

Touch-induced scraping sounds and texture perception

Sound is often the result of human–object interaction (touch, striking, scraping, etc.) and conveys to the listener required information about physical attributes of the interaction, and spatial properties of the sound event, e.g., location, geometry. People are highly skilled in using touch-produced sounds to identify texture properties. Loudness and pitch of the touch-induced scraping sounds are the important psychoacoustical determinants of the texture perception [S. J. Lederman, Perception 8, 93–103 (1979)]. In this study, psychophysical experiments were conducted to investigate the relationship between auditory properties (loudness and pitch) and texture perception. In order to control the psychoacoustical parameters, the scraping sounds were synthesized in computer environment. The results of the experiments show that subjects were able to differentiate the roughness of textures on the basis of pitch and loudness differences. Decreasing pitch tends to result in increasing magnitude of perceived roughness.