Digital Filter Coefficient Scaling for Transient Minimization

The patent applies preliminary action by pre-scaling the filter coefficients before the gain change occurs in the PGA. The coefficients are adjusted in advance to compensate for the upcoming gain transition, ensuring that when the gain changes, the filter output remains continuous and transients are avoided. This proactive coefficient adjustment resolves the contradiction by preparing the system ahead of time to handle the gain switching without generating audible artifacts.

The patent implements parameter changes by dynamically adjusting the filter coefficients based on the gain setting. When the PGA gain changes to achieve different dynamic ranges, the filter coefficients are correspondingly scaled to maintain proper filter behavior. This parameter adaptation allows the system to switch between dynamic acoustic overload points while keeping the filter response continuous, thereby eliminating audible transients.

The patent merges the compensation function into the filter coefficient values themselves. Instead of implementing a separate digital compensation block that processes the signal independently, the compensation is embedded directly in the filter coefficients that are applied during normal filtering operations. This integration achieves signal linearity compensation while reducing device complexity by eliminating redundant processing stages.

The filter performs self-compensation by using its own coefficient scaling mechanism to correct linearity issues. The same filtering operation that processes the audio signal also applies the necessary compensation when coefficients are appropriately scaled. This self-service approach achieves linear signal output without requiring additional dedicated compensation circuitry, thereby reducing overall device complexity.