Which adjustment would reduce the noise in the Doppler waveform in this image?

Noise in the Doppler waveform can often be attributed to excessive gain settings. Decreasing the Doppler gain reduces the amplification of both the signal and the noise, thus providing a clearer and more accurate Doppler waveform. Excessive gain can cause speckling and clutter, which obscure the true Doppler signals. By reducing the gain, the noise level is minimized, resulting in a cleaner Doppler signal representation.