Acoustic analog to multiple avoided-crossings in two coupled acoustic cavities

A closed cylindrical pipe with an inner partition wall forms two one-dimensional cavities. These each exhibit acoustic modes at certain well-defined frequencies. partial transmission through the leads to interactions between cavities' modes, and hence avoided crossings modes' This system is analogous a quantum that has multi-level interacting sub-systems and, thus, exhibits multiple crossings. Such analog realized studied by measuring sound as function of frequency partially transmitting movable partition. An excellent agreement obtained experimental results simple model based on wave reflection different interfaces.