volume

Value: [<percentage> | silent | x-soft | soft | medium | loud | x-loud]
Initial: x-loud
Applies to: all elements
Inherited: yes
Percentage values: N/A

The volume CSS property sets the volume of the speaking voice of the TTS engine. The volume is expressed as a percentage of the maximum volume: 0 means silence, and 100 means maximum volume. This property also supports several additional values, including:

• silent - 0% of maximum volume
• x-soft - 25% of maximum volume
• medium - 50% of maximum volume
• loud - 75% of maximum volume
• x-loud - 100% of maximum volume

By default, the volume CSS property of the Microsoft TTS engine is set to 100. Note that this differs from the range set through the control tags, which is 0-FFFF, for each channel (0 - silence, 0xFFFFFFFF - 100, 0x80008000 - 50).