This study investigates ways to enhance the stability of foam used for foam concrete manufacturing. In previous research, it was noticed that pre-made foam quickly deteriorates after being mixed into fresh concrete; such behavior results in low concrete porosity and insufficient acoustic performance. This research aims to find a way to correct the aforementioned problem and accordingly improve the quality of the concrete porous system. Specifically, the impact of hydration retarder incorporation on foam stability is examined. Samples containing 0.1, 0.3, and 0.4 wt% of hydration retarder Retardal 540 (R) were manufactured. Afterwards, bulk density, tensile and compressive strengths, and sound absorption coefficient of the hardened samples were measured. It was concluded that the addition of setting retarder into concrete composition results in increased porosity and high sound absorption coefficient, with the best values being measured for the sample with 0.3 wt% of retarder.