The sound of books is correct.
The sound of reading is clear and loud.
Source: Volume 3 of "Notes of Yuewei Thatched Cottage" by Ji Yun of the Qing Dynasty: "In the Ming Dynasty, there was a scholar walking alone in the bushes, hearing the sound of books, and it was strange that there was something in the wilderness."
Translation: There was a scholar in the Ming Dynasty who was walking alone in the jungle and grass. When he heard the clear and loud sound of reading, he was surprised that there was no sound of reading in the wilderness.
Sentence: Turning around the mountain, I saw a beautiful house with the sound of books coming from inside. Oh, it turned out to be a school.
Extended information:
Synonyms of the sound of books:
1. catchy
Pinyin: lǎng lǎng shàng kǒu
Meaning: It refers to the loud and smooth voice when reciting poetry and articles.
From: Modern Lao She's "Poetry and Allegro": "Prose is not subject to so many restrictions, although prose also pays attention to a sonorous tone and being catchy."
2. Langlang Catchy?
Pinyin: láng láng shàng kǒu?
Meaning: A metaphor for the loud sound of reading. Refers to proficiency in reading and speaking smoothly. It also means that the diction is popular and easy to recite orally.
Source: "Songyin Man Lu" by Wang Tao of the Qing Dynasty: "I have loved literacy since childhood; I was taught Tang poetry, which is catchy."
Translation: I have loved literacy since childhood; Taught Tang poetry; can also recite it proficiently and fluently.
Baidu Encyclopedia - The sound of reading is catchy
Baidu Encyclopedia - The sound of reading is catchy