Hofgaard was born in Berg, Østfold, and was brother-in-law of Lars Havstad.

[1] Hofgaard had employed the "speaking method" on very talented deaf students with good results; still it surprised many when he declared that he would use the method with the deafblind girl Ragnhild Tollefsdatter Kåta, probably among the first deafblind who learned to talk.

[1][2] Hofgaard reasoned that a deaf and blind child would have most use of learning to speak (rather than using e.g. the finger alphabet).

During the summer of 1889, Kåta met with Mary Swift Lamson (1822–1909) who had taught Laura Bridgman at the Perkins School for the Blind.

In 1890, ten-year-old Helen Keller was introduced to the story of Kåta and was inspired by her ability to learn to speak.