Abstract: A tactile-acoustic transducer comprises a vibrator plate, microphone means and first and second electrode members which are connected to a source of information through a tuneable network. The microphone means are coupled to a computer having display devices and a control output delivering control signals to the tuneable network. Rubbing the vibrator plate with the fingertip of his middle finger allows an operator to assess two different states of the transducer, perceived as "stick" and "non-stick" rubbing conditions, the "stick" condition being accompanied by emission of a characteristic sound and occurring when the network is tuned exactly in accordance with the phenomenon or condition of the source to be detected or measured.