进行翻译：计算梯度时则依然可以基于声学假设。因为梯度大小只取决于反传的残差源中波形扰动的大小波场的幅值此时是系数项对计算结果的影响会被迭代步长所矫正。

When calculating gradients, acoustic assumptions can still be based on. This is because the magnitude of the gradient depends only on the size of the waveform perturbation in the residual source being backpropagated, and the amplitude of the wavefield is a coefficient at this point, with its effect on the calculation result being corrected by the iteration step size.