20.500.12556/RUL-149724 Transmission loss measurement of recycled granular material using wave decomposition by impulse response extraction based on deconvolution A simplified method for measuring transmission loss with a single fixed microphone inside an impedance tube is proposed. The separation of the incident wave from the reflected wave is achieved by deconvolving the loudspeaker driver voltage signal with the microphone signal to extract the impulse response. Random noise and a sinusoidal sweep signal were used as excitation signals for extraction of the impulse response, and two deconvolution methods were employed: linear deconvolution based on the adaptive LMS algorithm and simple spectral division. To avoid the overlap of incident and reflected pulses, a long impedance tube was used. Using a long impedance tube eliminates the need for an anechoic tube termination and the need to calibrate microphones. It is found that a reflective tube termination provides more accurate results compared to an approximately anechoic termination. The approximately anechoic termination shortens the available time window of the reflected pulse because it reflects some of the low-frequency sound. The standard deviation of the results and the dynamic range of the proposed method were determined experimentally. The applicability of the new method was tested on samples of unconsolidated granular material recycled from construction sites. The measured transmission losses of the different granular fractions were compared with a theoretical model for transmission losses at low frequencies. Samples consisting of smaller granule fractions were found to have surprisingly high transmission loss values. The design of the extended vertical impedance tube in combination with the proposed method is cost effective, speeds up the measurement procedure and provides reliable results. transmission loss impedance tube pulse separation wave decomposition deconvolution granular materials prenosne izgube impedančna cev ločevanje pulzov valovna dekompozicija dekonvolucija granulirani materiali true false true Angleški jezik Slovenski jezik Članek v reviji 2023-09-08 13:07:05 2023-09-08 13:07:09 2024-02-07 09:11:12 0000-00-00 00:00:00 2023 0 0 10 str. Vol. 211, art. 109498 Aug. 2023 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 534:62-492 0003-682X 10.1016/j.apacoust.2023.109498 163841027 Zeleznik...-Transmission_loss_measurement_of_recycled_granular_material_using_wave_decomposition_by_impulse_response_extraction_based_on_deconvolution.pdf Zeleznik...-Transmission_loss_measurement_of_recycled_granular_material_using_wave_decomposition_by_impulse_response_extraction_based_on_deconvolution.pdf 1 5E8764E043D2E3ADCD273A7A7782C749 76a20833d17f733fa47eaa045704afdbf276622dc7087f6729ab851ae83d9736 5846febc-4e38-11ee-9323-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=174225 https://www.sciencedirect.com/science/article/pii/S0003682X23002967 1 d95dc824-4e37-11ee-9323-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=174223 Fakulteta za strojništvo 0 0 0