Higher-Order Ambisonics (HOA) reproduction with conventional mode-matching decoders can exhibit the so-called “ring of silence,” characterised by sound level reduction in specific spatial or spectral regions. This effect arises in loudspeaker reproduction when the number of loudspeakers exceeds that required by the Ambisonic order, and in binaural rendering when head-related transfer functions (HRTFs) are sampled at a higher spatial resolution than supported by the input signal. This paper investigates the extent to which advanced Ambisonic decoding strategies can mitigate this artefact. In particular, decoders based on Lasso regularisation and magnitude least-squares (magLS) are evaluated through numerical simulations in both loudspeaker and binaural reproduction scenarios. The results show that both approaches significantly reduce the prominence of the ring of silence compared to conventional minimum-norm mode-matching decoders. In loudspeaker reproduction, a more uniform spatial distribution of SPL is obtained, while in binaural rendering, spectral consistency is improved. An interpretation of these results is proposed, linking the observed behaviour to the underlying optimisation criteria of the decoding process. The results indicate that the ring of silence is not an inherent limitation of Ambisonics, but rather a consequence of the decoding strategy, and can be effectively mitigated through appropriate decoder design.
