1. A speech processor, comprising: a unit-selection device that processes a stream of target phonetic-units to produce a stream of respective selected phonetic-units, the selected phonetic-units being selected on the basis of at least a set of target-cost functions that determine target-costs between each target phonetic-unit and respective groups of sample phonetic-units; and a phonetic editor configured to enable an operator to selectively designate one or more selected phonetic-units in the stream of selected phonetic-units.