In this paper, a robust DWPT based adaptive bock algorithm with modified threshold for denoising the sounds of musical instruments is proposed. The signal is first segmented into multiple blocks depending upon the minimum mean square criteria in each block, and then thresholding methods are used for each block. All the blocks obtained after denoising the individual block are concatenated to get the final denoised signal. The discrete wavelet packet transform provides more coefficients than the conventional discrete wavelet transform (DWT), representing ad-ditional subtle detail of the signal but decision of optimal decomposition level is very important. Hence, the optimal wavelet and level of decomposition may be different for each signal. The obtained denoised signal with this algorithm is close to the original signal. -In this paper, a robust DWPT based adaptive bock algorithm with modified threshold for denoising the sounds of musical instruments is proposed. The signal is first segmented into multiple blocks depending upon the minimum mean square criteria in each block, and then thresholding methods are used for each block. All the blocks obtained after denoising the individual block are concatenated to get the final denoised signal. The discrete wavelet packet transform provides more coefficients than the conventional discrete wavelet transform (DWT), representing ad-ditional subtle detail of the signal but decision of optimal decomposition level is very important.　Hence, the optimal wavelet and level of decomposition may be different for each signal. The obtained denoised signal with this algorithm is close to the original signal.