It was developed into a teaching aid to help children acquire reading and writing skills. Like the pronunciation key in a dictionary, Unifon attempts to match each of the sounds of spoken English with a single symbol, though not all sounds are distinguished. The method was tested in Chicago, Indianapolis and elsewhere during the 1960s and 1970s, but no statistical analysis of the outcome was ever published in an academic journal. Interest by educators has been limited, but a community of enthusiasts continues to publicize the scheme and advocate for its adoption.