1. A device configured to decode a bitstream representative of higher-order ambisonic (HOA) audio data, the device comprising: one or more processors configured to: obtain a multi-transition indication of whether an ambient HOA coefficient is in transition during a same frame of the bitstream as a foreground audio signal is in transition; and obtain a vector that describes a spatial characteristic of a corresponding foreground audio signal based on the multi-transition indication, the vector defined in a spherical harmonic domain; render, based on the vector, one or more speaker feeds; and output the one or more speaker feeds to one or more speakers; and a memory coupled to the one or more processors, and configured to store the vector.