Gehörlosenpädagogik
Foster's work establishing 32 schools in 13 African countries led to the governments in Ghana and Nigeria adopting and replicating his school systems on a nationwide scale. Additionally, Foster trained a group of deaf Nigerians to run his mission schools in the country. This group of people were coined the Deaf Nigerian Pioneers, and were recorded to have worked to sustain and enhance the Deaf education system throughout Africa. It must also be noted that Foster's dedication to teaching a signed language encouraged previously-running deaf schools in Africa, such as the Wesley School for the Deaf, to adopt similar methods. Ultimately, Foster's work allowed for the use of sign language to grow throughout Africa, increasing opportunities for children throughout the continent.