n this paper, a new dynamic noise reduction

algorithm is proposed based on time-variety filter (TVF), which

can be implemented in both time and modified discrete cosine

transform (MDCT) domain. In time domain, an IIR filter with

changeable bandwidth is for the TVF. In frequency domain,

combined with MDCT transform, the noise is suppressed in

MDCT domain. A few experiment results reveal that the

algorithm retains the noise-suppressing performance with low

delay and algorithm complexity.