gōng / chéng / shī / zhèng / zài / tiáo / zhěng / tiáo / fú / fàn / wéi / yǐ / gǎi / shàn / shēng / yīn / zhì / liàng

工程师正在调整调幅范围，以改善声音质量。

The engineer is adjusting the modulation range to improve sound quality.