Students of speech therapy and audiology are often faced with the difficulty of obtaining a realistic view of the speech reception abilites of the hearing impaired. Illustrating speech recognition defects is a demanding task for the teaching staff, too. To improve the students' awareness of the effects of hearing defects, an interactive multimedia programme allowing simulation of various types of hearing impairment was constructed and placed on an Internet media server for online use. The simulated hearing-impaired speech material was produced using digital signal processing (e.g. mixing and filtering of speech and noise) and multimedia and audio technologies which enable streaming of sound files on the Internet. In the programme, word recognition scores for several degrees and types of hearing impairment in varying conditions of background noise and reverberation time can also be computed.