Provided is a system and method for converting digital data audio data audio data that has a predetermined input sample rate, into an analog data signal. In at least some embodiments, an authorisation request is received from a user terminal of the user at a first network element of the first packet-based communication network, the authorisation request comprising a first user identity. The second set of opening includes a plurality of elongated holes extending through the plate transverse to the longitudinal axis of the plate.