The user of a binaural hearing aid or communication system is to be provided with an easier assignment or identification of acoustic signals generated in the system for keeping a user informed about current settings or states of the system. The data includes a plurality of words residing in a table having rows and columns, each word residing in a different row and each letter of the word occupying a different column in that row. The relation between the bandgaps Eg1 and Eg2 is Eg1<Eg2. Exemplary coils described herein are particularly suited for very high-frequency MRI measurements.