A tool which provides relevant feedback on learners’ attempts at phonemic transcription is described. The tool aims to complement courses in transcription which are currently taught in both linguistics and language learning settings. A variety of types of feedback are provided. These can be staged by a tutor in order to support customization for different groups of learners and course levels. The tool consists of two similar standalone applications (for tutors and learners). The system performs an optimal alignment of student versus model transcriptions using a dynamic programming algorithm, modified to handle optional and alternative pronunciations. As a result, it computes a summary of errors and their locations within the attempt. Portability and internationalization are key design goals, supported in practice through the use of Java and XML. The tool is currently being tested in a controlled experiment which will provide considerable information on its actual usefulness and necessary refinements.