This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
Q: There is a theory that vinyl records can audibly represent higher frequencies than compact discs. According to Red Book specifications, the compact disc has a frequency response of 20 Hz up to 22,050 Hz, and most CD players measure flat within a fraction of a decibel from at least 20 Hz to 20 kHz at full output. Turntable rumble obscures the low-end limit of vinyl but the upper end can be, with some cartridges, reasonably flat within a few decibels to 30 kHz, with gentle roll-off. Carrier signals of Quad LPs popular in the 1970s were at 30 kHz to be out of the range of human hearing. The average human auditory system is sensitive to frequencies from 20 Hz to a maximum of around 20,000 Hz. The upper and lower frequency limits of human hearing vary per person.
A:
What is generally the lowest sound a human can hear?