5. The method of claim of claim 3 , wherein determining the mapping comprises: determining a first vector that includes representations of first acoustic features in the plurality of first-language speech sounds, and a second vector that includes representations of second acoustic features in the plurality of second-language speech sounds; determining a third vector that includes association probabilities between the first vector and the second vector; and determining the mapping based on the third vector.
5. The method of claim of claim 3 , wherein determining the mapping comprises: determining a first vector that includes representations of first acoustic features in the plurality of first-language speech sounds, and a second vector that includes representations of second acoustic features in the plurality of second-language speech sounds; determining a third vector that includes association probabilities between the first vector and the second vector; and determining the mapping based on the third vector. 6. The method of claim 5 , wherein determining the mapping comprises a linear regression that includes repeating the determining of the third vector and the determining of the mapping based on the third vector until convergence of linear regression variables in the linear regression.