Threatening noise exposure can cause temporary hearing loss, measured as a temporary threshold shift (TTS) of 10–40 dB that may last from minutes to days depending on exposure level and duration. In the described mouse experiment, two hours of exposure to 100 dB noise in the 8–16 kHz band also produced acute loss of inner-hair-cell ribbon synapses, followed by degeneration of auditory nerve fibers over the mice's lifetimes. Thus, a temporary hearing threshold change can occur alongside lasting auditory damage from the same noise exposure.