```
public final class AVAudioEnvironmentDistanceAttenuationModel
extends java.lang.Object
```
[@enum] AVAudioEnvironmentDistanceAttenuationModel Types of distance attenuation models Distance attenuation is the natural attenuation of sound when traveling from the source to the listener. The different attenuation models listed below describe the drop-off in gain as the source moves away from the listener. AVAudioEnvironmentDistanceAttenuationModelExponential distanceGain = (distance / referenceDistance) ^ (-rolloffFactor) AVAudioEnvironmentDistanceAttenuationModelInverse distanceGain = referenceDistance / (referenceDistance + rolloffFactor * (distance – referenceDistance)) AVAudioEnvironmentDistanceAttenuationModelLinear distanceGain = (1 – rolloffFactor * (distance – referenceDistance) / (maximumDistance – referenceDistance)) With all the distance models, if the formula can not be evaluated then the source will not be attenuated. For example, if a linear model is being used with referenceDistance equal to maximumDistance, then the gain equation will have a divide-by-zero error in it. In this case, there is no attenuation for that source. All the values for distance are specified in meters.

Class AVAudioEnvironmentDistanceAttenuationModel