TY  - CONF
A1  - Dokhanchi, Najmeh Sadat
A2  - Arnold, Jörg
T1  - Acoustic travel time tomography: Applicability of an array of directional sound sources
N2  - The technique of Acoustic travel-time TOMography (ATOM) allows for measuring the distribution of air temperatures throughout the entire room based on the determined sound-travel-times of early reflections, currently up to second order reflections. The number of detected early reflections in the room impulse response (RIR) which stands for the desired sound paths inside the room, has a significant impact on the resolution of reconstructed temperatures. This study investigates the possibility of utilizing an array of directional sound sources for ATOM measurements instead of a single omnidirectional loudspeaker used in the previous studies [1–3]. The developed measurement setup consists of two directional sound sources placed near the edge of the floor in the climate chamber of the Bauhaus-University Weimar and one omnidirectional receiver at center of the room near the ceiling. In order to compensate for the reduced number of sound paths when using directional sound sources, it is proposed to take high-energy early reflections up to third order into account. For this purpose, the simulated travel times up to third-order image sources were implemented in the image source model (ISM) algorithm, by which these early reflections can be detected effectively for air temperature reconstructions. To minimize the uncertainties of travel-times estimation due to the positioning of the sound transducers inside the room, measurements were conducted to determine the exact emitting point of the utilized sound source i.e. its acoustic center (AC). For these measurements, three types of excitation signals (MLS, linear and logarithmic chirp signals) with various frequency ranges were used considering that the acoustic center of a sound source is a frequency dependent parameter [4]. Furthermore, measurements were conducted to determine an optimum excitation signal based on the given condition of the ATOM measurement set-up which defines an optimum method for the RIR estimation correspondingly. Finally, the uncertainty of the measuring system utilizing an array of directional sound sources was analyzed.
KW  - Bauphysik
KW  - Akustische Laufzeit-Tomographie
KW  - Acoustic Travel-Time Tomography
KW  - Bauklimatik
Y1  - 2022
UR  - https://e-pub.uni-weimar.de/opus4/frontdoor/index/index/docId/4658
UR  - https://nbn-resolving.org/urn:nbn:de:gbv:wim2-20220622-46589
UR  - https://www.dega-akustik.de/publikationen/online-proceedings
N1  - This conference paper has been submitted to the DAGA 2022. Thus, the original paper first is published in the "Fortschritte der Akustik - DAGA 2022"
ER  -