Therefore, the song should be modified for different learners, such as the visually, physically, and hearing challenged learners. Is this sentence grammatically correct?

The sentence is not grammatically correct. A better construction would be;

Therefore, the song should be modified for different learners, such as the visually, physically, and hearing-impaired learners.

Explanation:

For a sentence to be seen as grammatically correct, there must be subject-verb agreement, correct use of punctuations, and proper usage of qualifiers. In the sentence above, there is a subject-verb agreement.

A problem with grammar can be seen in the use of the phrase, "hearing challenged". A better usage should be hearing-impaired. The hyphen was omitted. Impaired is also a better adjective for those with hearing problems.

- the heat nearly killed them that first summer.

that’s a nice boss :