The measured values of the sound pressure level in ordinary rooms in dwellings vary depending on the combined effect of the absorption and the scattering of the furniture, or to the presence of absorbent surfaces on walls and ceilings. Regarding the measurement of noise from building services, ISO 16032 and ISO 10052 methods allow to normalize the sound pressure levels to a reference reverberation time of 0,5s. Several European countries incorporate this reverberation time correction into their regulations. However, Spanish regulations, specifically RD 1367/2007, and the majority of regional decrees and ordinances concerning the evaluation of noise from activities or equipment within buildings, do not incorporate this correction, even when measurements are performed in two scenarios: before the building's occupation when rooms are empty, or when the building is fully furnished, as may occur in the case of complaints. For that reason, this study compares the values of the reverberation time index obtained in 180 residential rooms using various methods while also evaluating the benefits and drawbacks of their application.