Scaling of internal noise in discrete cosine transform (DCT) domain has been presented for copyright protection of audio signals. Watermark as a logo is embedded into the most prominent peaks of the highest energy segment of the audio DCT coefficients. Tuning of the DCT coefficients of the watermarked signal by noise-induced resonance improves the authenticity of the watermarked signal. This scaling is produced by noise-induced resonance, generally known as Dynamic stochastic resonance (DSR). DSR utilizes the noise introduced during different signal processing attacks and it induced here as an iterative process due to which the effect of noise is suppressed and hidden information is enhanced. Response of the proposed extraction scheme suggests increased robustness against various attacks such as noise addition, cropping, re-sampling, re-quantization, MP3 compression, and echo. Comparison with the existing DCT, DWT and SVD techniques shows the better performance in terms of correlation coefficient and visual quality of extracted watermark. © 2012 Springer-Verlag GmbH.