A sound measured at 40 decibels is considered to be relatively quiet. It is comparable to the noise level of a quiet library or a soft conversation. This level of sound is often found in peaceful environments, making it suitable for activities that require concentration or relaxation. In comparison, normal conversation typically ranges from 60 to 70 decibels. Sounds below 40 decibels, such as a whisper or rustling leaves, are less intrusive and can create a calming atmosphere. Understanding decibel levels helps in managing noise pollution and maintaining a comfortable sound environment in places like homes and offices.