[Archives de la Parole]. , Bag mta ; Voske taz / Kokor Talânc, chant

[Traditions. Asie. Russie. Arménie]

[Archives de la Parole]. , Azat ara ; Zov gišer : pesnâ / Kokor Talânc, chant

[Traditions. Asie. Russie. Arménie]

[Archives de la Parole]. , Cmern ancav ; Vor mahkanacu / zapevala s horom ; Makar Vardikân, chef de choeur

[Traditions. Asie. Russie. Arménie]

[Archives de la Parole]. , Hani ; Jarab astvac / Pogos Atamân, chant

[Traditions. Asie. Russie. Arménie]

[Archives de la parole]. , Chants populaires arméniens / Hubert Pernot, éd. ; Mlle Marguerite Babaïan, chant

[Traditions. Europe. Arménie]

[Archives de la parole]. , Ampel a, dzoun tchi gali : l'abandonnée / Hubert Pernot, éd. ; Mlle Marguerite Babaïan, chant. Chant de mariage : [chant populaire des indiens Yakima]. Berceuse : [chant populaire des indiens Yakima] / Hubert Pernot, éd. ; M. Paul Coze, présentation ; Chef Os-Ko-Mon, voix

[Traditions. Europe. Arménie. Amérique du Nord. Etats-Unis]

[Archives de la parole]. , Chants populaires arméniens / Hubert Pernot, éd. ; Mlle Marguerite Babaïan, chant

[Traditions. Europe. Arménie]

[Archives de la parole]. , Poésies et proses / [Alexandre] Sakellinos [i. e. Sakellionos], voix. Conversation en grec / [Alexandre] Sakellinos [i. e. Sakellionos], [Georges] Tsocanakis, voix

Enregistrement : Paris, Université de Paris, La Sorbonne, 19-05-1914

[Archives de la parole]. , Langue Cuambi / Kakumbi [i. e. Kakuambi], voix. Langue Kimbundu / Mohongo, voix

[Traditions. Afrique. Angola]

[Archives de la parole]. , Conversation / Mohongo & Kakuambi, voix

[Traditions. Afrique. Angola]

Sound pressure level in a municipal preschool

Aim: To evaluate the sound pressure level to which preschool students are exposed. Method: This was a prospective, quantitative, nonexperimental, and descriptive study. To achieve the aim of the study we used an audio dosimeter. The sound pressure level (SPL) measurements were obtained for 2 age based classrooms. Preschool I and II. The measurements were obtained over 4 days in 8-hour sessions, totaling 1920 minutes. Results: Compared with established standards, the SPL measured ranged from 40.6 dB (A) to 105.8 dB (A). The frequency spectrum of the SPL was concentrated in the frequency range between 500 Hz and 4000 Hz. The older children produced higher SPLs than the younger ones, and the levels varied according to the activity performed. Painting and writing were the quietest activities, while free activities period and games were the noisiest. Conclusion: The SPLs measured at the preschool were higher and exceeded the maximum permitted level according to the reference standards. Therefore, the implementation of actions that aim to minimize the negative impact of noise in this environment is essential.

An inverse method to obtain porosity, fibre diameter and density of fibrous sound absorbing materials

Characterization of sound absorbing materials is essential to predict its acoustic behaviour. The most commonly used models to do so consider the flow resistivity, porosity, and average fibre diameter as parameters to determine the acoustic impedance and sound absorbing coefficient. Besides direct experimental techniques, numerical approaches appear to be an alternative to estimate the material’s parameters. In this work an inverse numerical method to obtain some parameters of a fibrous material is presented. Using measurements of the normal incidence sound absorption coefficient and then using the model proposed by Voronina, subsequent application of basic minimization techniques allows one to obtain the porosity, average fibre diameter and density of a sound absorbing material. The numerical results agree fairly well with the experimental data.

Evaluation of Two Alternative Procedures for Measuring Airflow Resistance of Sound Absorbing Materials

It is well known that sound absorption and sound transmission properties of open porous materials are highly dependent on their airflow resistance values. Low values of airflow resistance indicate little resistance for air streaming through the porous material and high values are a sign that most of the pores inside the material are closed. The laboratory procedures for measuring airflow resistance have been stan- dardized by several organizations, including ISO and ASTM for both alternate flow and continuous flow. However, practical implementation of these standardized methods could be both complex and expensive. In this work, two indirect alternative measurement procedures were compared against the alternate flow standardized technique. The techniques were tested using three families of eco-friendly sound absorbent materials: recycled polyurethane foams, coconut natural fibres, and recycled polyester fibres. It is found that the values of airflow resistance measured using both alternative methods are very similar. There is also a good correlation between the values obtained through alternative and standardized methods.

Science and technology : 47 video, film, and sound/slide programs for earth sciences, computer sciences, civil engineering, and general science classes.

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