Electropalatography

Electropalatography (EPG) measures tongue contact with the hard-palate during speech and provides both qualitative and quantitative data on the place of articulation.


How does it work?

EPG determines tongue-palate contact by using a special artificial palate that contains a number of electrodes embedded on its tongue-facing surface. A small electrical signal is fed to the patient, which is conducted through the tongue to any touched electrodes. These tongue-palate contact patterns are then displayed on the computer screen.

icSpeech supports multi-channel EPG and is compatible with the Linguagraph system. The palate is custom-made by a dental technician and simply clips to the upper teeth.

Linguagraph EPG
Reading EPG Palate

Palatogram Display

Palatograph Display

The real-time palatograph display is a useful biofeedback tool that allows the patient to visualise tongue movement during speech. Segments are arranged in palatal zones and rows to depict the individual EPG contacts.

This example illustrates the palatograph for the /s/ sound. The individual segments have been colour coded to highlight the following palatal zones:

  • Alveolar (blue) - front two rows.
  • Palatal (green) - middle three rows.
  • Velar (red) - rear three rows.

Waveform Display

The Waveform display is often used in therapy because it allows the patient to see the dynamics of their speech during the utterance of complete words or phrases.

This example shows the Alveolar (blue), Palatal (green) and Velar (red) tongue-palate contact waveforms for the word "Missing".

With Linguagraph, up to nine waveforms can be displayed:

  • Alveolar
  • Palatal
  • Velar
  • Left Contact
  • Center Contact
  • Right Contact
  • Contact Balance
  • Center-of-Gravity
  • Contact weight
Lingual Waveform Display