You may use the make-up gain and automatic source normalization to adjust the volume of each of your audio sources. These volume controls, as opposed to other volume controls in Wwise, are transparent from all logical behavior based on volumes. For example, they have no effect on whether a voice is considered below threshold (virtual), and they are ignored when evaluating HDR attenuation. They don't appear in the Voice Monitor either.
The total value of these source-specific gains is displayed in the column Normalization / Make-Up Gain in the Voices tab of the Wwise Profiler.
The loudness data collected in the analysis phase of your original files may be used by Wwise to automatically normalize your assets at run-time based on their estimated loudness. You can choose either of the following loudness measurement types:
Integrated loudness computation loosely follows the ITU-R BS 1770 recommendation for loudness measurement: K-weighting filtering and absolute and relative gating at -70 dB and -10 dB respectively, on 400 ms windows with 75% overlap. This is most useful for long audio program material such as music or cinematics.
Momentary Max loudness computation uses K-weighting filtering and a short 100 ms window with 75% overlap. The maximum value over the entire file is chosen. This is appropriate for short individual audio elements such as sound effects.
The default target loudness for normalization is -23 dB as per BS 1770. You can customize this target by adjusting the Loudness Target property.
Source normalization is non-destructive: the sound's analyzed loudness value is stored separately by Wwise, and a proper normalization gain is applied at run-time. This gain is a function of the measured and target loudness: gain = -measured - target [dB]. For example, if a sound's analyzed loudness is -37 dB and source normalization is enabled with the default target of -23, Wwise will apply a normalization gain of +14 dB (+37 - 23) at run-time. If a sound's analyzed loudness is -12 dB, the normalization gain will be -11 dB (+12 - 23). In other words, soft sounds are boosted and loud sounds are attenuated. If you are unhappy with the normalization gain that is calculated based on loudness, you may tweak it further using the make-up gain.