Loudness Measurements Research Articles

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Different ballistic definitions for the momentary time scale used in live loudness measurement were evaluated. Definitions from the ITU and EBU were compared as well as a faster version of the ITU ...

Why Balloons Make a Loud Noise When They Pop

Measurements of balloon loudness and pressure signatures are presented for a variety of balloon shapes. The loudness and recordings were made 3.2 meters from the popped balloons. The balloons were of 3 types: round, long, and extremely long (the same type that is used to make balloon animals), filled with 3 gases, and inflated to multiple sizes. The data indicates that all 3 types of latex balloons share similar peak frequencies and acoustic signatures in spite of differences in shape and diameter or length when inflated. The data also shows a correlation of loudness to the ratio of specific heats of the gas and inflated diameter of the balloons. The data does not support some of the common hypotheses of balloon popping noise generation. It appears that the sound is generated by the vibration of the balloon surface and the ruptured edge of the latex. This explanation is consistent with the current acoustic measurements and shadowgraph videos, and the hypothesis of Patynen, et al.

Evaluation of a Protocol for Integrated Speech Audiometry.

Purpose This project was aimed at evaluating the reliability, validity, and clinical utility of a protocol for integrated measurements of the most comfortable level (MCL) and uncomfortable level (UCL) for speech, in combination with the speech recognition threshold (SRT). We also evaluated the validity of using spondee words when measuring speech MCL and UCL. Method In a randomized block design, equal numbers of women and men with normal hearing, aged 18-29 years, were assigned to each of 3 experimental stimulus conditions: spondee singlets, spondee triplets, or connected discourse ( n = 12 per group). Following measurement of the SRT, a modified method of limits was employed to establish, on a 7-point loudness rating scale, an ascending MCL, a descending MCL, and an ascending UCL. A single instructional set covered all loudness measurements. Test times were tracked electronically to assess clinical efficiency. All test conditions were repeated during each of 2 separate test sessions. Results Mean SRTs, MCLs, and UCLs across the 3 different experimental groups were found not to differ statistically or clinically (mean differences < 5 dB). Intrasession and intersession reliability for the various measures were excellent, and testing of all listeners was completed in a timely manner. In a follow-up experiment with adults with normal hearing who were only a decade older than participants in our main experiment, the older group was found to have significantly higher MCLs and UCLs. Conclusions Spondee words can be used routinely to obtain reliable, valid, and clinically efficient measures of MCLs and UCLs for speech, in a protocol combined with the SRT. Spondees, presented singly, yielded the greatest level of efficiency overall. Results support a recommendation to obtain an ascending measurement of MCL prior to a descending measurement and to establish the MCL by averaging the 2 values.

Clinical profile and implications of tinnitus in individuals with and without hearing loss.

To compare clinical characteristics of tinnitus and interference in quality of life in individuals with and without associated hearing loss, as well as to discuss the association of quantitative measurements and qualitative instruments. A quantitative, cross-sectional and comparative study approved by the Research Ethics Committee (No. 973.314/CAEE: 41634815.3.0000.0106) was carried out. The responses of the psychoacoustic assessment of tinnitus (intensity, frequency, minimum masking level and loudness discomfort level for pure tone and speech), as well as the Tinnitus Handicap Inventory (THI) questionnaire, and the visual analogue scale (VAS) were compared between 15 patients with tinnitus and peripheral hearing loss (group I) and 16 adults with normal hearing (group II). The mean VAS and THI scores obtained in GI were 5.1 (+1.5) and 42.3 (+18), and in GII, 5.7 (+2.6) and 32.7 (+25), respectively. This result suggests moderate GI annoyance and moderate/mild GII annoyance (p>0.005). There was a positive and moderate correlation between THI and VAS only in GII. In the psychoacoustic evaluation, significant differences were observed between the groups regarding the measurement of loudness (*p=0.013) and the minimum masking level (*p=0.001). There was no direct influence of the presence of hearing loss in relation to the impact of tinnitus. The differences found between the groups regarding the psychoacoustics measures can be justified by the presence of cochlear damage. The objective measurement of tinnitus, regardless of the presence or absence of peripheral hearing loss, is an important instrument to be used along with self-evaluation measures.

Relationship Between Tinnitus Loudness Measure by Visual Analogue Scale and Psychoacoustic Matching of Tinnitus Loudness.

The aim of the study was to assess the relationship between psychoacoustic matches of tinnitus loudness and tinnitus loudness measured with a visual analogue scale (VAS) in patients with normal hearing and patients with hearing loss. Cross-sectional study. A clinical group of 140 adult patients (46.4% women, 53.6% men) aged from 19 to 81 years old who had had tinnitus for at least 6 months were included in the study. The most frequent reported localization of their tinnitus sensation was bilateral (48.6%); 40% experienced unilateral tinnitus; and 11.4% heard tinnitus in the head. All participants were first asked to complete a VAS to indicate their tinnitus loudness. Hearing thresholds were then determined for each patient at frequencies from 0.125 to 8 kHz; loudness and frequency of the tinnitus were also matched psychoacoustically. Tinnitus loudness measured in dB SL was significantly lower in patients with bilateral hearing loss than in patients with unilateral hearing loss or in patients with normal hearing. Tinnitus loudness measured with VAS was significantly higher in patients with bilateral hearing loss than in patients with normal hearing. In patients with normal hearing there was a relationship between psychoacoustic matches of tinnitus loudness and tinnitus loudness measured with VAS, but this relationship did not hold for the hearing loss patients. The VAS scale for tinnitus loudness does not generally correspond to psychoacoustic measures of tinnitus loudness. It is only indicative for tinnitus patients who have normal hearing.

Summary of Propagation Cases of the Second AIAA Sonic Boom Prediction Workshop

A summary is provided for the propagation portion of the second AIAA Sonic Boom Prediction Workshop, held 8 January 2017 in conjunction with the AIAA SciTech 2017 Conference. Near-field pressure waveforms for two cases were supplied, and ground signatures at multiple azimuthal angles as well as their corresponding loudness metrics were requested from 10 participants, representing three countries. Each case had some required as well as some optional runs. The required cases included atmospheric profiles with measured data including winds, using radiosonde balloon data at multiple geographically spread locations. The humidity profiles provided for the optional cases were taken from American National Standards Institute guidance. Participants provided ground signatures along with the requested data, including some loudness metrics using their best practices, which included lossy as well as lossless atmospheric propagation schemes. All the participants’ submissions, for each case, are compared and discussed. Noise or loudness measures are calculated, and detailed comparisons and statistical analyses are performed and presented. It has been observed that the variation in the loudness measures and spread between participants’ submissions increased as the computation proceeded from undertrack locations toward the lateral cutoff. Lessons learned during this workshop are discussed, and recommendations are made for potential improvements and possible subsequent workshops.

이명 치료에서 항우울제의 효과

Background and Objectives: Tinnitus is one of the common symptom that designate a significant comorbidity with anxiety and depression. Among antidepressants, a selective serotonin reuptake inhibitor (SSRI) is frequently used in pharmacological protocols for the management of tinnitus. This study aims to verify the effect of the SSRI on the patients with tinnitus. Subjects and Methods: Thirty-eight patients with chronic tinnitus, who visited in Pusan National University Hospital from Jan 2015 to December 2016 were investigated prospectively. Pretreatment and posttreatment by taking SSRI Visual analogue scale (VAS) measurements of tinnitus loudness (intensity), duration, annoyance, impact of life, and Tinnitus Handicap Inventory (THI) and its subcategory (functional, emotional, catastrophic) were evaluated and compared. Results: Four subjects were dropped out due to intolerability. VAS measurements such as annoyance, impact of life were improved significantly after treatment. In THI score, not only total score but also subcategory scores were got better, which had statistical significance. Conclusions: Our results show that SSRI could positive effect on chronic tinnitus patients with considerable tolerability. But it might be necessary the evidence-based approach such as double blind randomized controlled trial to clarify the effect of SSRI on tinnitus. (J Clinical Otolaryngol 2018;29:36-41)

Effects of ear canal occlusion on hearing sensitivity: A loudness experiment.

Over the last century, hearing research has repeatedly reported differences in loudness perception when different types of transducers are being used. One of the effects of using different transducers is that listening may be performed via an open ear (loudspeaker), a cushioned ear (headphones), or an occluded ear (hearing aid receivers, insert earphones). The question of whether varying the acoustic load applied to the ear canal might impact hearing sensitivity has therefore become essential given the need to establish realistic noise damage risk criteria in an attempt to prevent noise-induced hearing loss for any given listening condition. Although such loudness discrepancies in the cushioned ear have been recently proven to be caused by loudness measurement artifacts, currently available data do not exclude a possible impact of ear canal occlusion on loudness perception. This paper presents the results of a loudness balance test carried out on 18 normal-hearing listeners. Using an earplug to occlude the canal, in-ear sound pressure levels were compared between the occluded ear and the cushioned ear at equal loudness. The results show agreement within 1 dB between the two listening conditions, and support the conclusion that loudness does not depend on the type of acoustic load applied to the ear canal.

Influence of suppression on restoration of spectral loudness summation in listeners with hearing loss.

Loudness depends on both the intensity and spectrum of a sound. Listeners with normal hearing perceive a broadband sound as being louder than an equal-level narrowband sound because loudness grows nonlinearly with level and is then summed across frequency bands. This difference in loudness as a function of bandwidth is reduced in listeners with sensorineural hearing loss (SNHL). Suppression, the reduction in the cochlear response to one sound by the simultaneous presentation of another sound, is also reduced in listeners with SNHL. Hearing-aid gain that is based on loudness measurements with pure tones may fail to restore normal loudness growth for broadband sounds. This study investigated whether hearing-aid amplification that mimics suppression can improve loudness summation for listeners with SNHL. Estimates of loudness summation were obtained using measurements of categorical loudness scaling (CLS). Stimuli were bandpass-filtered noises centered at 2 kHz with bandwidths in the range of 0.1-6.4 kHz. Gain was selected to restore normal loudness based on CLS measurements with pure tones. Gain that accounts for both compression and suppression resulted in better restoration of loudness summation, compared to compression alone. However, restoration was imperfect, suggesting that additional refinements to the signal processing and gain-prescription algorithms are needed.

Voice, Articulation, and Prosody Contribute to Listener Perceptions of Speaker Gender: A Systematic Review and Meta-Analysis

The aim of this study was to provide a systematic review of the aspects of verbal communication contributing to listener perceptions of speaker gender with a view to providing clinicians with guidance for the selection of the training goals when working with transsexual individuals. Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) guidelines were adopted in this systematic review. Studies evaluating the contribution of aspects of verbal communication to listener perceptions of speaker gender were rated against a new risk of bias assessment tool. Relevant data were extracted, and narrative synthesis was then conducted. Meta-analyses were conducted when appropriate data were available. Thirty-eight articles met the eligibility criteria. Meta-analysis showed speaking fundamental frequency contributing to 41.6% of the variance in gender perception. Auditory-perceptual and acoustic measures of pitch, resonance, loudness, articulation, and intonation were found to be associated with listeners' perceptions of speaker gender. Tempo and stress were not significantly associated. Mixed findings were found as to the contribution of a breathy voice quality to gender perception. Nonetheless, there exists significant risk of bias in this body of research. Speech and language clinicians working with transsexual individuals may use the results of this review for goal setting. Further research is required to redress the significant risk of bias.

Deriving loudness growth functions from categorical loudness scaling data.

The goal of this study was to reconcile the differences between measures of loudness obtained with continuous, unbounded scaling procedures, such as magnitude estimation and production, and those obtained using a limited number of discrete categories, such as categorical loudness scaling (CLS). The former procedures yield data with ratio properties, but some listeners find it difficult to generate numbers proportional to loudness and the numbers cannot be compared across listeners to explore individual differences. CLS, where listeners rate loudness on a verbal scale, is an easier task, but the numerical values or categorical units (CUs) assigned to the points on the scale are not proportional to loudness. Sufficient CLS data are now available to assign values in sones, a scale proportional to loudness, to the loudness categories. As a demonstration of this approach, data from Heeren, Hohmann, Appell, and Verhey [J. Acoust. Soc. Am. 133, EL314-EL319 (2013)] were used to develop a CUsone metric, whose values were then substituted for the original CU values in reanalysis of a large set of CLS data obtained by Rasetshwane, Trevino, Gombert, Liebig-Trehearn, Kopun, Jesteadt, Neely, and Gorga [J. Acoust. Soc. Am. 137, 1899-1913 (2015)]. The resulting data are well fitted by power functions and are in general agreement with previously published results obtained with magnitude estimation, magnitude production, and cross modality matching.

種々の変動音の評価法としてのL_&lteq&gtの妥当性並びにその適用範囲の検討

種々の変動音の評価法としてのL_&lteq&gtの妥当性並びにその適用範囲の検討

Frequency characteristics of bone conduction actuators – Measurements of loudness and acceleration

Loudness as a subjective measurement and acceleration as an objective measurement were taken to measure the frequency characteristics of four different bone conduction actuators. The loudness of bone conduction was measured by balancing bone-conducted stimuli at 17 frequencies from 0.2kHz to 8kHz. The acceleration at equal loudness, which was measured by a Brüel & Kjær 4930 artificial mastoid, was transferred to relative levels for comparison with the loudness measurements. A relationship between loudness and acceleration was difficult to find for a bone conduction actuator of inner-ear type while for a head-of-mandible type, a relationship was found at some frequencies. Furthermore, otoacoustic emission of a head-of-mandible actuator was measured. It was hypothesized that loudness can be estimated by objective measurements of bone conduction actuators at specific frequencies.

A history of loudness before 1950

Loudness is a perceptual correlate of the physical intensity of a sound, but the relationship between loudness and intensity is not simple. The derivation from loudness-matching data of equal-loudness contours for tones across frequency was described as early as 1927. However, the most influential work on loudness prior to 1950 was the formulation by Fletcher and Munson (1933) of a method for calculating the loudness of any steady sound from the intensities of its frequency components. In a subsequent publication, Fletcher and Munson (1937) described how the loudness of a tone changes in the presence of another tone, which is a phenomenon known as masking. Stevens (1936) made extensive contributions to the theory of loudness scaling and methods for loudness measurement. Miller (1947) discovered that “just detectable increments in intensity” were of the same order of magnitude for noise as for pure tones.” Dix et al. (1948) suggested a clinical use in differential diagnosis of hearing loss for the phenomenon known as loudness recruitment, which is defined as an abnormally-rapid loudness growth. In part because of its relevance to the remediation of hearing loss, the measurement, quantification, and prediction of loudness continue to be active areas of psychophysical research.

Consideration of Methodology and Measures of Loudness.

Consideration of Methodology and Measures of Loudness.

Repeated Measurement of Absolute and Relative Judgments of Loudness: Clinical Relevance for Prescriptive Fitting of Aided Target Gains for soft, Comfortable, and Loud, But Ok Sound Levels.

This study was undertaken with the purpose of streamlining clinical measures of loudness growth to facilitate and enhance prescriptive fitting of nonlinear hearing aids. Repeated measures of loudness at 500 and 3,000 Hz were obtained bilaterally at monthly intervals over a 6-month period from three groups of young adult listeners. All volunteers had normal audiometric hearing sensitivity and middle ear function, and all denied problems related to sound tolerance. Group 1 performed judgments of soft and loud, but OK for presentation of ascending sound levels. We defined these judgments operationally as absolute judgments of loudness. Group 2 initially performed loudness judgments across a continuum of seven loudness categories ranging from judgments of very soft to uncomfortably loud for presentation of ascending sound levels per the Contour Test of Loudness; we defined these judgments as relative judgments of loudness. In the same session, they then performed the absolute judgments for soft and loud, but OK sound levels. Group 3 performed the same set of loudness judgments as did group 2, but the task order was reversed such that they performed the absolute judgments initially within each test session followed by the relative judgments. The key findings from this study were as follows: (1) Within group, the absolute and relative tasks yielded clinically similar judgments for soft and for loud, but OK sound levels. These judgments were largely independent of task order, ear, frequency, or trial order within a given session. (2) Loudness judgments increased, on average, by ∼3 dB between the first and last test session, which is consistent with the commonly reported acclimatization effect reported for incremental changes in loudness discomfort levels as a consequence of chronic bilateral hearing aid use. (3) Measured and predicted comfortable judgments of loudness were in good agreement for the individual listener and for groups of listeners. These comfortable judgments bisect the measured levels judged for soft and for loud, but OK sounds. (4) Loudness judgments within the same loudness category varied across listeners within group by as much as 50 to 60 dB. Such large variation in judgments of loudness is problematic, especially because hearing-impaired listeners are known to exhibit similarly large ranges of intersubject response variation and, yet, poplar prescriptive fitting strategies continue to use average rather than individual loudness data to fit nonlinear hearing aids. The primary conclusions drawn from these findings are that reliable absolute judgments of soft and loud, but OK are clinically practical and economical to measure and, from these judgments, good estimates of comfortable loudness can also be predicted for individuals or for groups of listeners. Such loudness data, as measured as described in this report, offer promise for streamlining and enhancing prescriptive fitting of nonlinear hearing aids to target gain settings for soft (audible), comfortable, and loud, but OK (tolerable) sound inputs for the individual listener.

Simple reaction time for broadband sounds compared to pure tones

Although many studies have explored the relation between reaction time (RT) and loudness, including effects of intensity, frequency, and binaural summation, comparable work on spectral summation is rare. However, most real-world sounds are not pure tones and typically have bandwidths covering several critical bands. Since comparing to a 1-kHz pure tone, the reference tone, is important for loudness measurement and standardization, the present work focuses on comparing RTs for broadband noise to those for 1-kHz pure tones in three experiments using different spectral and binaural configurations. The results of Experiments 1 and 2 yield good quantitative agreement with spectral loudness summation models for moderate and high sound pressure levels, measured using both pink noise covering almost the entire hearing range and bandpass-filtered pink noise with different center frequencies. However, at lower levels, the RT measurements yield an interaction of level and bandwidth, which is not in line with loudness scaling data. In Experiment 3, which investigated the binaural summation of broadband sounds, the binaural gain for white noise was determined to be 9 dB, which is somewhat larger than what had been found in previous RT measurements using 1-kHz pure tones.

Individual differences in judging the annoyance of the sounds of helicopters

A rarely used procedure for studying aviation noise annoyance is asking people ro rate indiviidual aircraft events experienced in their homes. Our study employs this procedure with five subjects who self-identified as “highly annoyed” by helicopters. Subjects lived within 400 m of each other. Flights were recorded at three homes over a 10 day survey period during which subjects registered their judgments on a cell phone app with which a subject initiated a survey by tapping “hear a helicopter.” Questions included location (indoors/outdoors), window position (open/closed), annoyance (5 pt scale), loudness (3 pt scale), and house rattles (3 pt scale). Recordings corresponding to completed surveys were analyzed for ASEL, CSEL, subjective and objective duration, loudness, loudness level, fluctuation strength, and roughness. Stepwise regression was used to find the most robust predictors of annoyance. The data confirmed the importance of ASEL and/or measures of loudness as predictors. Compared with in-home obs...

Development of a multi-category psychometric function to model categorical loudness measurements.

A multi-category psychometric function (MCPF) is introduced for modeling the stimulus-level dependence of perceptual categorical probability distributions. The MCPF is described in the context of individual-listener categorical loudness scaling (CLS) data. During a CLS task, listeners select the loudness category that best corresponds to their perception of the presented stimulus. In this study, CLS MCPF results are reported for 37 listeners (15 normal hearing, 22 with hearing loss). Individual-listener MCPFs were parameterized, and a principal component analysis (PCA) was used to identify sources of inter-subject variability and reduce the dimensionality of the data. A representative "catalog" of potential listener MCPFs was created from the PCA results. A method is introduced for using the MCPF catalog and maximum-likelihood estimation, together, to derive CLS functions for additional participants; this technique improved the accuracy of the CLS results and provided a MCPF model for each listener. Such a technique is particularly beneficial when a relatively low number of measurements are available (e.g., International Standards Organization adaptive-level CLS testing). In general, the MCPF is a flexible tool that can characterize any type of ordinal, level-dependent categorical data. For CLS, the MCPF quantifies the suprathreshold variability across listeners and provides a model for probability-based analyses and methods.

"Measurement" of Tinnitus.

Chronic tinnitus is the persistent sensation of hearing a sound that exists only inside the head. The prevalence of tinnitus in adults in the United States is estimated at 10 to 15%. For about 20% of these individuals the tinnitus is significantly bothersome. Although myriad therapies for tinnitus are offered (often at significant cost), most are not evidence based. Difficulty in the assessment and further development of interventions for tinnitus stems from the limitations of techniques used to evaluate these interventions. Questionnaires are widely available to "measure" (tinnitus can only be indirectly measured) functional effects of tinnitus, such as difficulty sleeping and concentrating, and negative emotions such as anxiety, depression, and annoyance. Questionnaires have recently been documented for sensitivity to change in response to intervention (i.e., "responsiveness"). All of these questionnaires function well to assess the overall impact of tinnitus. The limitations mentioned pertain primarily to measures of tinnitus perception, which typically include the psychoacoustic measures of tinnitus loudness and pitch matches, tinnitus spectral content, minimum masking levels, and residual inhibition. These measures, which are obtained routinely in many clinics and as part of research studies, have not been validated for being diagnostic, prognostic, discriminative, or responsive. In order for these measures to become clinically meaningful, normative standards are needed, both for baseline measures and for repeated measures of tinnitus perception. Evidence-based intervention for tinnitus requires accurately measuring both the perception of, and reactions to, tinnitus.