Objective and subjective assessment of PET felt recycled panels as an acoustic treatment in the meeting rooms

This study presents the performance of the PET-felt recycled panels for the room acoustic treatment. As the objective parameters, Reverberation Time (RT) and Speech Transmission Index (STI) were measured with B&K DIRAC, an omnidirectional loudspeaker, and power amplifier in the meeting room at the Department of Interior Design, Bilkent University, Ankara, Turkey, before the acoustic treatment. Following ISO 12913-2 Method A, Perceived Affective Quality (PQA), Appropriateness, and Assessment of the Acoustic Environment were measured. Fifteen participants who were occupants of the meeting room were selected for the questionnaire survey to be conducted using the snowball method. The findings showed that the reverberation time was five seconds at 1 kHz, which is insufficient, and the acoustic quality could have been better for the speech-purpose room. PET-felt recycled acoustic panels were applied to the ceiling and walls as a solution. After the acoustic treatments, all procedures were repeated with the same. The results showed that significant improvements have been provided in both objective and subjective assessments. RT was in the optimum range. The participants found the meeting room with PET-felt recycled panels more pleasant and eventful after the acoustic treatment.