The rise of asynchronous communications such as email and messaging accelerated a long-running decline in the traditional voice phone call. Now, when they occur, synchronous one-to-one voice calls themselves tend to be scheduled rather than spontaneous and perhaps as a result have been largely neglected by mobile operators over recent years. Yet at the same time, use of voice itself has enjoyed something of a revival in asynchronous mode in various guises, as in personal assistants, remote control for TV services and within user interfaces more generally, and this has been intensified by the pandemic and its stay-at-home scenarios. This is the background as 5G Voice over New Radio (VoNR) emerges as a sequel to VoLTE (Voice over LTE). It…