Use of a telephone and GSM phones, in particular, was assessed by means of a postal interview sent to all adult Finnish implantees. The response rate was very high (87%). Fifty-one of the 61 respondents used a telephone and 27/61 also used a mobile phone, usually a digital phone. Two GSM phone models from Nokia (3110 and 6110) were tested with three different cochlear implant systems used by nine patients. Definite differences between the processors were found. Nucleus Spectra (two implantees) could not be used with any of the GSM phones under any test condition. Nucleus SPrint was incompatible with both GSM phone models in a poor field, while GSM phone model 6110 could be used in a good field. The Med-El Combi 40+ processor was compatible with both GSM models tested under any condition.