7dB
7dB refers to a sound pressure level of 7 decibels. The decibel (dB) is a logarithmic unit used to express the ratio of two values of a physical quantity, most commonly sound power or sound intensity. In the context of sound pressure level, 7 dB represents a very quiet sound. For comparison, normal conversation is typically around 60 dB, and the threshold of hearing is generally considered to be 0 dB.
The human ear's perception of loudness is logarithmic, meaning that a doubling of sound intensity is perceived