“发低沉的声音”可以表达为“make a deep/low-pitched sound” 或者 “emit a deep/low voice” 。
例如：
The big dog made a deep sound, which scared the little cat.（那只大狗发出了低沉的声音，把小猫吓坏了。）
The engine emitted a low-pitched sound as it started up.（发动机启动时发出了低沉的声音。）