Silent vacuum cleaners
≤ 65 dB
— a noise level of 65 dB is approximately equivalent to a conversation between 2-3 people at a distance of 1 m. It is a rather low volume by the standards of vacuum cleaners; the quietest models in this category give out only about 40 dB — this is the average volume of speech on normal tones (and the minimum volume allowed for constant noise sources in living quarters during the day)Show
