The per-voice equalizer (accessed in Settings> Accessibility> VoiceOver> Speech> Your Chosen Voice), which allows users to customize certain tonal/frequency characteristics of a voice, does not work. Changes made to the Equalizer do nothing when applied.
1. Ensure VoiceOver is enabled.
2. Navigate to Settings> Accessibility> VoiceOver> Speech> (Your selected voice).
2. Navigate to and select the 'Equalizer' button.
3. Change values in the Equalizer for more of the frequency ranges.
4. Observe that changing values in the Equalizer appears to have no impact on the tonal character of the voice.