Search

During their creative process, designers routinely seek the feedback of end users. Yet, the collection of perceptual judgments is costly and time-consuming, since it involves repeated exposure to the designed object under elementary variations. Thus, considering the practical limits of working with human subjects, randomized protocols in interactive sound design face the risk of inefficiency, in the sense of collecting mostly uninformative judgments. This risk is all the more severe that the initial search space of design variations is vast. In this paper, we propose heuristics for reducing the design space considered during an interactive optimization process. These heuristics operate by using an approximation model, called surrogate model, of the perceptual quantity of interest. As an application, we investigate the design of pleasant and detectable electric vehicle sounds using an interactive genetic algorithm. We compare two types of surrogate models for this task, one based on acoustical descriptors gathered from the literature and the other based on behavioral data. We find that reducing by a factor of up to 64 an original design space of 4096 possible settings with the proposed heuristics reduces the number of iterations of the design process by up to 2 to reach the same performance. The behavioral approach leads to the best improvement of the explored designs overall, while the acoustical approach requires an appropriate choice of acoustical descriptor to be effective. Our approach accelerates the convergence of interactive design. As such, it is particularly suitable to tasks in which exhaustive search is prohibitively slow or expensive., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Souaille et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Machine listening systems for environmental acoustic monitoring face a shortage of expert annotations to be used as training data. To circumvent this issue, the emerging paradigm of self-supervised learning proposes to pre-train audio classifiers on a task whose ground truth is trivially available. Alternatively, training set synthesis consists in annotating a small corpus of acoustic events of interest, which are then automatically mixed at random to form a larger corpus of polyphonic scenes. Prior studies have considered these two paradigms in isolation but rarely ever in conjunction. Furthermore, the impact of data curation in training set synthesis remains unclear. To fill this gap in research, this article proposes a two-stage approach. In the self-supervised stage, we formulate a pretext task (Audio2Vec skip-gram inpainting) on unlabeled spectrograms from an acoustic sensor network. Then, in the supervised stage, we formulate a downstream task of multilabel urban sound classification on synthetic scenes. We find that training set synthesis benefits overall performance more than self-supervised learning. Interestingly, the geographical origin of the acoustic events in training set synthesis appears to have a decisive impact.

A method for optimizing the inner shape of brass instruments using sound simulations is presented. This study considers different objective functions and constraints (representative of both the intonation and the spectrum of the instrument) for a relatively large number of design variables. A complete physics-based model, taking into account the instrument and the musician's embouchure, is used to simulate steady regimes of sounds by means of the harmonic balance technique, the instrument being represented by its input impedance. The design optimization variables are related to the geometrical dimensions of the resonator. The embouchure's parameters are varied during the optimization procedure to obtain an average behavior of the instrument. The objective and constraint functions of the optimization problem are evaluated using the physics-based simulation model, which is computationally expensive. Moreover, the gradients of the objective and constraint functions can be discontinuous, unavailable, or hard to approximate reliably. Therefore, a surrogate-assisted derivative-free optimization strategy using the mesh adaptive direct search algorithm was employed. One example of a B♭ trumpet's bore is used to demonstrate the effectiveness of the design optimization approach: the obtained results improve previously reported objective function values significantly.

This paper introduces a new experimental protocol for studying mental representations of urban soundscapes through a simulation process. Subjects are asked to create a full soundscape by means of a dedicated software tool, coupled with a structured sound data set. This paradigm is used to characterize urban sound environment representations by analyzing the sound classes that were used to simulate the auditory scenes. A rating experiment of the soundscape pleasantness using a seven-point bipolar semantic scale is conducted to further refine the analysis of the simulated urban acoustic scenes. Results show that (1) a semantic characterization in terms of presence/absence of sound sources is an effective way to characterize urban soundscape pleasantness, and (2) acoustic pressure levels computed for specific sound sources better characterize the appraisal than the acoustic pressure level computed over the overall soundscape.

This study focuses on a particular attribute of trumpet tones, the brightness, and on the physical characteristics of the instrument thought to govern its magnitude. On the one hand, an objective study was carried out with input impedance measurements, and, on the other hand, a subjective study with hearing tests and a panel of subjects. To create a set of different trumpets a variable depth mouthpiece was developed whose depth can be easily and continuously adjusted from "deep" to "shallow." Using this mouthpiece and the same trumpet, several instruments were generated which may be played in three ways: (i) by a musician, (ii) by an artificial mouth, and (iii) using physical modeling simulations. The influence of the depth of the mouthpiece on the perception of the trumpet's tones was investigated, and the ability of a musician, the artificial mouth, or physical modeling simulations to demonstrate perceptively noticeable differences was assessed. Physical characteristics extracted from the impedance curves are finally proposed to explain the brightness of trumpet tones. As a result, the physical modeling simulations now seem to be mature enough to exhibit coherent and subtle perceptual differences between tones. This opens the door to virtual acoustics for instrument makers.

Experimental results of a special artificial trombone player are presented: A mechanical device is a substitute for the musician. Wind instruments, and particularly the brass, are self-sustained oscillators. The oscillations are induced by a mechanical oscillator (the lips of the player) acting as a valve which modulates the flow. Measured mechanical parameters of the artificial buzzing lips for different "embouchures of the player" are presented, and analyzed in connection with the played frequencies obtained for the same "embouchures." The results are obtained with two resonator systems (a mouthpiece alone and a trombone with its mouthpiece).

Background: The benefits of preoperative chemotherapy and radiation for esophageal carcinoma are under investigation. A pilot study was undertaken to determine if pathologic assessment of tumor regression correlated with disease free survival., Methods: Ninety-three resected specimens from patients treated with cis-dichloro-diamino cisplatin and irradiation before surgery were examined on semiserial sections. Patients selected for surgery were all Status 1 according to the World Health Organization (WHO) classification. Histologic typing was based on the WHO classification. Tumor regression grade (TRG) was quantitated in five grades: TRG 1 (complete regression) showed absence of residual cancer and fibrosis extending through the different layers of the esophageal wall; TRG 2 was characterized by the presence of rare residual cancer cells scattered through the fibrosis; TRG 3 was characterized by an increase in the number of residual cancer cells, but fibrosis still predominated; TRG 4 showed residual cancer outgrowing fibrosis; and TRG 5 was characterized by absence of regressive changes. Survival curves were estimated according to the Kaplan-Meier method. A quantification of the relationship between treatment failure and confounding variables (age, tumor location, tumor size, esophageal wall involvement by residual cancer and/or regressive changes, histology, treatment, adequacy of surgery, pathologic lymph node status, and tumor regression grade) was done using Cox's proportional hazards model., Results: Forty-two percent of specimens were TGR 1-2; 20%, TGR 3; and 33%, TGR 4-5. Univariate analysis found that tumor size, pathologic lymph node status, tumor regression grade, and esophageal wall involvement were highly correlated with disease free survival (P < 0.05). After multivariate analysis, only tumor regression (i.e., TRG 1-3 versus TRG 4-5) remained a significant (P < 0.001) predictor of disease free survival., Conclusions: This study highlights the importance of tumor regression in the survival of patients with esophageal carcinoma treated with preoperative chemoradiotherapy. These findings suggest that tumor regression grade should be considered when evaluating therapeutic results.

A statistical analysis of a result on a human basophile degranulation test was performed. The shape of the curve representing the number of basophiles, as a function of the logarithm of the allergenic dosage, was parabolic, in the case of degranulation. This curve permits a calculation of the dosage necessary to provoke a degranulation of 10 per cent, in comparison with the mean of the two control test tubes. The authors also determined the significant degranulation threshold to be 5 per cent, as regards the mean number of cells counted for the controls (example: for 50 control cells counted, the threshold was equal to 28 per cent degranulation). This statistical analysis largely facilitates the interpretation of the granulation test by basophiles, by assuring the value of observed degranulations, and by allowing a better quantification of the phenomenon. The latter might permit a comparison of different batches of allergen, that is, the standardisation of allergens. These calculations can be easily programmed, using a currently available calculator.

The various studies which have dealt up to the present with a possible relationship between asbestosis and HLA groups have led to differing conclusions. The present study evaluated this relationship by comparison of 57 workers with asbestosis confirmed radiologically (minimum S1 type opacities) and functionally (VC and/or DuaCO less than 88%) with 58 controls from the same population. In a second phase, statistical analysis involved the combination of these cases with those reported in the literature, estimating the mean relative risk and, for each gene, the heterogeneity of the results thus collected. No relation was found between class I (A and B) HLA antigens and asbestosis. The authors suggest extension of this study to class II (DR) and III (components of complement) antigens and to seek possible links between combinations of antigens and the development of asbestosis.

In geographical epidemiology, the correlation between two variables is often studied, using as basic units those zones for which these variables are available. However, because of their geographical contiguity, it could be misleading to consider each of these zones as independent statistical units. Moreover, spatial distributions (either of the factor or of the disease) are often distributed in relatively simple patterns; these patterns may induce strong correlations. Thus, the general pattern of the spatial distribution of the variables should be investigated before any attempt to infer epidemiological interpretation of a relationship. This paper presents an algorithm to construct contiguous groupings which are similar enough with regard to one of the two variables considered and to thus divide the original set of geographical areas into contrasting zones. The algorithm is easy to compute and allows mapping of the geographical distribution of the variable studied. It also lessens the risk of duplication of basic information by reducing the autocorrelation of one of the variables.

The serum levels of IgG, IgA and IgM as well as total proteins were followed from birth to one year of age in a sample of 44 infants. Values for a 'healthy' population are presented. The results of correlation analysis question current views on the independence of the different immunoglobulin classes.

Prognostic factors were evaluated in 109 soft tissue sarcomas of the extremities, walls of the trunk, head, and neck. All lesions were graded according to the systems proposed by the National Cancer Institute (NCI) and the French Federation of Cancer Centers (FNCLCC), and a correlation was found between tumor grade and prognosis. Univariate analysis selected the following variables as unfavorable prognostic factors: invasive tumor margins, extra-compartmental status, deep tumors, tumor diameters over 5 cm, inadequate excision, presence of necrosis, high mitotic count, histologically undifferentiated tumors, and blood vessel invasion. These variables were found to be interdependent. Multivariate analysis selected quality of surgery as the most important variable for predicting local recurrences. The factors selected with regard to overall and metastasis-free survival were tumor size, tumor margins, necrosis, and adequacy of excision. These results permitted classification of patients into four prognostic groups: two with good and two with bad prognosis. Five-year survival for the four groups was 100%, 83%, 53%, and 0%; 5-year metastatic rates were 0%, 12%, 67%, and 100%. Similar groups were obtained when the variables of tumor margins and size were combined with an adaptation of the NCI grading (low-grade tumors/high-grade tumors without necrosis/high-grade tumors with necrosis). Comparative analysis showed that patients with tumors of the same histologic grade or type were not necessarily classed in the same prognostic groups. A better clinicopathologic correlation was obtained using a combination of prognostic factors than with histologic grading or typing alone.

An improved version of a previously described photon absorptiometry method for measuring the bone mineral content of the femoral shaft is presented. The study included 267 healthy persons, who served as control subjects, and 31 osteoporotic and 3 osteomalacic female patients. A monoenergetic source of 241Am was used and a fully automatic apparatus designed. The examinations were recorded with an independent microcomputer and secondarily processed by the nuclear unit central computer. The guidelines of Cameron and West were used to perform various calculations from the initial absorption curve, and the clinical usefulness of these was tested. On the one hand, cortical bone density (CBD) and bone linear attenuation coefficient (BLAC) were found adequately to differentiate between osteoporotics and controls, but we defined a discriminative function (F) which allowed even better separation between the two groups. On the other hand, bone index (BI) was found to be the best parameter to follow an individual patient during therapy. These results underline the usefulness of these calculations for detecting and monitoring the progress of pathological states.

We have compared X-ray and lung function data in 106 asbestos workers with diverse, yet most often prolonged and important, exposure times. Based on the international B.I.T. classification, we have found a significant link between VC and type, density, opacity extent and presence of pleural thickening. The same relationship is found with alveolo-arterial ductance. On the whole, however, it is difficult to determine lung function condition with X-ray. Thus, certain criteria concerning function should be considered as well as radiography.

Successive evaluations of diphtheritic (AD) and tetanic antitoxin have been made from birth to twelve months in infants receiving at 3, 4 and 5 months an immunization with antidiphtheritic, antitetanic and absorbed antimeasles vaccine. The decrease of AD of maternal origin is not, contrary to common opinion, regularly exponential. Factors influencing the elimination of AD from maternal origin are discussed. An important decrease is often observed after the first immunizing infection. AD level evolution is independent from that to IgG but there is a correspondence at birth in mother and infant between the highest values of AD and the lowest values of total proteides. The commonly observed existence of AD in mother blood indicates the persistence in Maputo of a strong diphteric endemy, and this justifies the association of the antidiphtheritic vaccination to the antitetanic one. After immunization, high levels of antibodies are always reached for tetanic antitoxin and a little less, regularly, for AD. High levels of AD are more frequent in infants having demonstrated no infectious symptoms. Towards the end of the first year, antibodies levels frequently decrease. From these findings possible ways are discussed for immunizing infants in Africa with antitoxins.