Specifies whether the Voice Capture DSP applies microphone gain bounding.

Constant for IPropertyBag

Available only by using IPropertyStore.

Data Type


Default Value


Applies To


Microphone gain bounding ensures that the microphone has the correct level of gain. If gain is too high, the captured signal might be saturated and will be clipped. Clipping is a non-linear effect, which will cause the acoustic echo cancellation (AEC) algorithm to fail. If the gain is too low, the signal-to-noise ratio is low, which can also cause the AEC algorithm to fail or not perform well.

This property can have the following values.

Value Description
VARIANT_TRUE Enable microphone gain bounding.
VARIANT_FALSE Disable microphone gain bounding.


The default value of this property is VARIANT_TRUE (enabled).

Microphone gain bounding is applies only when the DSP operates in source mode. In filter mode, the application must ensure that the microphone has the correct gain level.


Minimum supported client
Windows Vista [desktop apps only]
Minimum supported server
Windows Server 2008 [desktop apps only]

See also

Media Foundation Properties

Voice Capture DSP