Robustness Against DA/AD Conversion: Concepts, Challenges, and Examples

Abstract

This chapter discusses the robustness of digital audio watermarking algorithms against digital to analogue and analogue to digital conversions. This is an important challenge in many audio watermarking applications. We provide an overview on distortions caused by converting the signal in various scenarios. This includes environmental influences like background noise or room acoustics when taking microphone recordings as well as sound sampling effects like quantization noise. The aim is to show the complexity of influences that needto be taken into account. Additionally, we show test results of our own audio watermarking algorithm with respect to analogue recordings using a microphone which proves that a high robustness in this area can be achieved. To improve even the robustness of algorithms, we briefly introduce strategies against downmixing and playback speed changes of the audio signal.