10 times the logarithm of the ratio of the mean-square pressure of a sound to the square of a reference sound pressure. Sound pressure level will usually be shortened to sound level on the DOSITS website. Sound pressure level is given in relative units named decibels (dB). Sound pressures for transient signals are sometimes given as peak or peak-to-peak pressures, rather than mean-square pressure. To avoid ambiguity, the units for sound pressure level can be written dB rms for dB root-mean-square.