This subunit consists of 5 activities. The following sequence of activities is recommended. Activities 4 and 5 are similar open-inquiry assignments. Half of the class could perform Activity 4 and half Activity 5.
| File ID | Activity Name | Inquiry Type | E-emphasis |
| i.3.1 | Sound graphs | Guided Inquiry | Engagment |
| i.3.2 | Model of human speech production | Interactive Discussion | Exploration / Explanation |
| i.3.3 | Sound signal analysis | Guided Inquiry | Exploration / Explanation |
| i.3.4 | Human speech analysis | Open Inquiry | Extend / Elaborate |
| i.3.5 | Human speech synthesis | Open Inquiry | Extend / Elaborate |