As part of our next update for ArtikPix Levels, we are including a sound development chart. The information in the chart is adapted from the speech sound developmental milestones mentioned in "When are Speech Sounds Learned?" JSHD, 37, (February 1972) by Eric Sander. Our chart will be included on the Information screen accessed via the home screen of ArtikPix Levels. Stay tuned to our blog to see when the ArtikPix Levels update is available. In the meantime, you can check out our sound development chart below. Tap on the image to view it full size.