Reduced bit rate ultra low delay audio coding

An audio coder with a very low delay (6-8 ms) for reduced bit rates is presented. Previous coder versions were based on backward adaptive coding, which has suboptimal noise shaping capabilities for reduced bit rate coding. We propose to use a different noise shaping method instead, resulting in an approach which uses forward adaptive predictive coding. We will show that, in comparison, the forward adaptive method has the following advantages: it is more robust against high quantization errors, has additional noise shaping capabilities, has a better ability to obtain a constant bit rate, and shows improved error resilience.