Units of Measure and Distance Factors

The default values for the 3D sound effects mimic the natural world. Many application designers choose to change these values, however, to make the effects more dramatic. Exaggerated Doppler effects or exaggerated sound attenuation with distance can make an application more exciting.

DirectSound's 3D effects use meters as the default unit of distance measurements. If your application does not use meters, it need not convert between units of measure to maintain compatibility with the component. Instead, the application can set a distance factor, which is a floating-point value that represents meters per application-specified distance unit. For example, if your application uses feet as its unit of measure, it could specify a distance factor of .30480006096, which is the number of meters in a foot.