Which one of the following is NOT a concept from language education?

Language education/teaching refers to a process whereby a child gains communicative comprehension or fluency over a language. It involves practice by learners where facilitation is provided by a teacher.

Concepts related to language education:

Print-rich environment:

A print-rich environment refers to the classroom environment in which students are exposed to different forms of print such as labels, instructions, pictures, etc.
It consists of context-based relevant material for children such as pictures, rhymes, etc, and provides visual cues to learners which are required to complete the language task.

Phonics:

Phonics is one of the most important building blocks of reading. It may be referred to as a method used for teaching the reading and writing skills of the English language, which develops the phonemic awareness of the learners.
It includes the ability to discriminate between sounds and shapes. It may provide self-confidence to obtain reading skills as it provides readers with a tool for tackling new words or for discovering the written words.

Dyslexia:

Dyslexia is a condition in which a student faces persistent challenges and difficulty in reading and comprehending the text because of frequently omitting substitutes or reversing the letters and words while reading.
When one faces difficulty in reading, s/he can not spell the words properly and is unable to write them accurately as well. Students having dyslexia get confused between similar words, sounds of alphabets, and the same shapes of letters.

Hence, it is clear that acoustics is NOT a concept from language education.

Hint

Acoustics is the science relating to sound production and listening, it deals with the clear transmission of sound speech, lectures, and music throughout the hall or building as a whole without any distortion.
Good acoustics promote comfortable living and working efficiency of occupants and increase the pleasure and satisfaction of listeners of music and speech in auditoriums. For comfortable occupancy of a building and meeting functional requirements, proper acoustics and sound insulation are required.
It is a matter of experience, proven by experimentation that high noise levels in buildings cause fatigue, mental strain, and loss of efficiency. It may even lead to deafness and nervous breakdown.
For some buildings, proper acoustics and sound insulation is of paramount importance, e.g. for radio and television studios, auditoriums, hospitals and educational institutions, etc