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Abstract-Compressed sensing (CS) samples signals at a much lower rate than the Nyquist rate if they are sparse in some basis. In this paper, the CS methodology is applied to sinusoidally modeled audio signals. As this model is sparse by definition in the frequency domain (being equal to the sum of a small number of sinusoids), we investigate whether CS can be used to encode audio signals at low bitrates. In contrast to encoding the sinusoidal parameters (amplitude, frequency, phase) as current state-of-the-art methods do, we propose encoding few randomly selected samples of the time-domain description of the sinusoidal component (per signal segment). The potential of applying compressed sensing both to single-channel and multi-channel audio coding is examined. The listening test results are encouraging, indicating that the proposed approach can achieve comparable performance to that of state-ofthe-art methods. Given that CS can lead to novel coding systems where the sampling and compression operations are combined into one low-complexity step, the proposed methodology can be considered as an important step towards applying the CS framework to audio coding applications.

Some recent neurophysical studies suggest that mammalian binaural decoding is based on count comparison. When asignal is presented earlier or with higher leveltoone ear,the neural signals are stronger in the auditory pathways leading to the contralateral hemisphere in such mechanisms. This paper describes functional countcomparison models of twobrainstem nuclei, medial superior olive (MSO)and lateral superior olive (LSO), both of which exist in both hemispheres. The topology of the organs and the connections between them as presented in the current neuroanatomical studies are imitated in the functional model. The parameters of the functional models are selected to fit existing neurophysiological and psychoacoustical data. It is shown that the proposed MSO and LSO models are sensitive to interaural differences in time and leveli naw ay that accounts for some known psychoacoustical phenomena.

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