1. A binaural hearing instrument set, comprising a first unit and a second unit, each of the units comprising processing circuitry, communication circuitry and memory circuitry, where: the processing circuitry and the memory circuitry are configured to execute at least a first data processing algorithm, the first data processing algorithm is configured such that it comprises software code that is configured to execute in a server mode and a client mode, the first unit comprises the software code that is configured to execute in the server mode, and the second unit comprises the software code that is configured to execute in the client mode, and the communication circuitry is configured to provide a communication channel between the software code that is configured to execute in the server mode in the first unit and the software code that is configured to execute in the client mode in the second unit, characterised in that: the processing circuitry and the memory circuitry are configured to execute a second data processing algorithm in addition to the first data processing algorithm, the second data processing algorithm is configured such that it comprises software code that is configured to execute in a server mode and a client mode, and the first unit comprises the software code of the second algorithm that is executable in the client mode, and the second unit comprises the software code of the second algorithm that is executable in the server mode.