| This figure compares the FAD calculated between clean background music and music distorted by a variety of methods (e.g., pitch down, Gaussian noise, etc.) to the associated worth values from human evaluation. Each type of distortion has two data points representing high and low extremes in the distortion applied. The quantization distortion (purple circles), for example, limits the audio to a specific number of bits per sample, where the two data points represent two different bitrates. Both human raters and the FAD assigned higher values (i.e., “less realistic”) to the lower bitrate quantization. Overall log FAD correlates well with human judgement — a perfect correlation between the log FAD and human perception would result in a straight line. |
