A large number of investigations have been under-taken to develop technical systems in order to enable a tactile substitution of speech for the deaf. These aids have been evaluated with various experimental procedures (identification and discrimination tests, learning experiments, tracking procedures and other overt behaviour methods). In order to find additional evidence for the processing and perception of such stimuli, in the present experiment psychophysiological responses during identification and discrimination tests using tactile speech stimuli were recorded. A 3-factorial ANOVA-design was used to evaluate test condition, task condition and habituation during the presentation of tactile speech stimuli. Besides the Ss' identification and discrimination answers, eye blink rate (BR) was registered and electrodermal activity (EDA) measured on both hands concomitantly. The results show that both psychophysiological measures (EDA and BR) very sensitively differentiate various task conditions. Blink rate clearly reflects a difference in the processing of identification and discrimination.