"低沉连续的声音" can be translated as "a deep, continuous sound" or "a low, uninterrupted noise" in English, depending on the specific context and nuance you want to convey.
"A deep, continuous sound" emphasizes the low pitch and the unbroken nature of the sound.
"A low, uninterrupted noise" also conveys the idea of a sustained, low-pitched sound, with "uninterrupted" highlighting its continuity.
Both expressions are appropriate and can be used interchangeably in many situations.