Abstract: A method (196) for providing speech therapy to a learner (30) utilizes a formant estimation and visualization process (28) executable on a computing system (26). The method (196) calls for receiving a speech signal (35) from the learner (30) at an audio input (34) of the computing system (26) and estimating first and second formants (136, 138) of the speech signal (35). A target (94) is incorporated into a vowel chart (70) on a display (38) of the computing system (26). The target (70) characterizes an ideal pronunciation of the speech signal (35). A data element (134) of a relationship between the first and second formants (136, 138) is incorporated into the vowel chart (76) on the display (38). The data element (134) is compared with the target (70) to visualize an accuracy of the speech signal (35) relative to the ideal pronunciation of the speech signal (35).