Abstract: The increasing globalization of the world necessitates further strengthening of foreign language learning policies. The brain's foreign language recognition activity is enhanced and effective foreign language learning is enabled by extracting signals of prescribed bands from a speech signal in a foreign language using a first bandpass filter section having two or more bandpass filters, extracting the envelopes of each frequency band signal using envelope extraction sections having envelope extractors, applying a noise source signal to a second bandpass filter section having two or more bandpass filters and extracting noise signals corresponding to the prescribed bands, multiplying the outputs of the first bandpass filter section and the second bandpass filter section in multiplication sections, summing up the outputs of the multiplication sections in an addition section to produce a Noise-Vocoded Speech Sound signal, and presenting the Noise-Vocoded Speech Sound signals for listening.