Sequential spaces are a spatial system comprising a series of single spaces connected in sequence by openings. They are not uncommon in the built environment and have similar acoustic characteristics with long and coupled spaces. To explore the sound attenuation and reverberation in such spaces, nine in situ measurements were conducted to examine the effects imposed by four factors, namely, opening on separating partition, number of separating partitions, source position, and acoustic absorption. Results revealed that if more rooms were connected by openings, although there could be significant changes in the distribution of sound pressure level, the resulting difference on the average level of each room is almost unobservable in the connecting rooms. In addition, T20 of each room decreases in the source and receiving rooms, especially in the rooms with a larger source distance. According to the source position, the level difference between adjacent rooms by the first separating partition is larger than those in the successive ones when the space is divided by different number of separating partitions in the same construction. A larger source–opening distance results in a larger level difference across the spaces unless the source is placed along the opening. Increasing acoustic absorption in some rooms did not affect the level difference between those unincreased rooms
