Sustainable Panels with Recycled Materials for Building Applications: Environmental and Acoustic Characterization☆

Abstract Sound absorption materials structure is generally based on porous synthetic media (rock wool, glass wool, polyurethane, polyester, ect.): they have expensive production processes, important energy consumptions, and high environmental impact. Recycled materials are becoming an interesting alternative, due to their good acoustic behavior, similar to traditional porous materials; they also allow low impact production costs, thanks to the use of wastes derived from other production cycles. This work focuses on the evaluation of the acoustic absorption properties of new panels made of recycled paper and other scrap materials, as wool and nonwoven polyester fabric: different samples were produced and tested by means of impedance tube, according to ISO 10534-2. In order to present the environmental benefits, Life Cycle Assessment was carried out in terms of primary embodied energy and greenhouse gas emissions, considering a "cradle-to-gate" approach. Furthermore, the behavior of innovative absorption materials was investigated in order to improve the acoustic performance of a lecture room, by means of an acoustic simulation software. A comparison with traditional materials was also carried out for both acoustic and environmental aspects. In the simulation model, calibrated by an in-situ experimental campaign of the main acoustic quality indexes (Reverberation Time, Clarity and Definition Indexes, Speech Transmission Index), different acoustic correction solutions were implemented: both the new recycled and traditional panels were applied as wall and ceiling absorbers. The analysis of the acoustic absorption trends, in 100 - 5000 Hz frequencies range, shows that the new materials are suitable as acoustic correction systems, especially the panel composed by waste paper and wool fibers. The LCA analysis results show that, considering the same acoustic performance, the recycled panels allow to reduce the environmental effects and the global production costs

Temporal development of compensation strategies for perturbed palate shape in German /S/-production

The palate shape of four speakers was changed by a prosthesis which either lowered the palate or retracted the alveoles. Subjects wore the prosthesis for two weeks and were recorded several times via EMA. Results of articulatory measurements show that speakers use different compensation methods at different stages of the adaptation. They lower the tongue immediately after the insertion of the prosthesis. Other compensation methods as for example lip protrusion are only acquired after longer practising periods. The results are interpreted as supporting the existence of different mappings between motor commands, vocal tract shape and auditory-acoustic target

The influence of the palate shape on articulatory token-to-token variability

Articulatory token-to-token variability not only depends on linguistic aspects like the phoneme inventory of a given language but also on speaker specific morphological and motor constraints. As has been noted previously (Perkell (1997), Mooshammer et al. (2004)) , speakers with coronally high "domeshaped" palates exhibit more articulatory variability than speakers with coronally low "flat" palates. One explanation for that is based on perception oriented control by the speaker. The influence of articulatory variation on the cross sectional area and consequently on the acoustics should be greater for flat palates than for domeshaped ones. This should force speakers with flat palates to place their tongue very precisely whereas speakers with domeshaped palates might tolerate a greater variability. A second explanation could be a greater amount of lateral linguo-palatal contact for flat palates holding the tongue in position. In this study both hypotheses were tested

Real-Time Vocal Tract Modelling

To date, most speech synthesis techniques have relied upon the representation of the vocal tract by some form of filter, a typical example being linear predictive coding (LPC). This paper describes the development of a physiologically realistic model of the vocal tract using the well-established technique of transmission line modelling (TLM). This technique is based on the principle of wave scattering at transmission line segment boundaries and may be used in one, two, or three dimensions. This work uses this technique to model the vocal tract using a one-dimensional transmission line. A six-port scattering node is applied in the region separating the pharyngeal, oral, and the nasal parts of the vocal tract