In everyday complex listening situations, sound emanating from several different sources arrives at the ears of a listener both directly from the sources and as reflections from arbitrary directions. For localization of the active sources, the auditory system needs to determine the direction of each source, while ignoring the reflections and superposition effects of concurrently arriving sound. A modeling mechanism with these desired properties is proposed. Interaural time difference ͑ITD͒ and interaural level difference ͑ILD͒ cues are only considered at time instants when only the direct sound of a single source has non-negligible energy in the critical band and, thus, when the evoked ITD and ILD represent the direction of that source. It is shown how to identify such time instants as a function of the interaural coherence ͑IC͒. The source directions suggested by the selected ITD and ILD cues are shown to imply the results of a number of published psychophysical studies related to source localization in the presence of distracters, as well as in precedence effect conditions.
A fundamental aspect of the "I" of conscious experience is that the self is experienced as a single coherent representation of the entire, spatially situated body. The purpose of the present study was to investigate agency for the entire body. We provided participants with performance-related auditory cues and induced online sensorimotor conflicts in free walking conditions investigating the limits of human consciousness in moving agents. We show that the control of full-body locomotion and the building of a conscious experience of it are at least partially distinct brain processes. The comparable effects on agency using audio-motor and visuo-motor cues as found in the present and previous agency work may reflect common supramodal mechanisms in conscious action monitoring. Our data may help to refine the scientific criteria of selfhood and are of relevance for the investigation of neurological and psychiatric patients with disturbance of selfhood.
Binaural Cue Coding (BCC) is a method for multichannel spatial rendering based on one down-mixed audio channel and BCC side information. The BCC side information has a low data rate and it is derived from the multichannel encoder input signal. A natural application of BCC is multichannel audio data rate reduction since only a single down-mixed audio channel needs to be transmitted. An alternative BCC scheme for efficient joint transmission of independent source signals supports flexible spatial rendering at the decoder. This paper (Part I) discusses the most relevant binaural perception phenomena exploited by BCC. Based on that, it presents a psychoacoustically motivated approach for designing a BCC analyzer and synthesizer. This leads to a reference implementation for analysis and synthesis of stereophonic audio signals based on a Cochlear Filter Bank. BCC synthesizer implementations based on the FFT are presented as low-complexity alternatives. A subjective audio quality assessment of these implementations shows the robust performance of BCC for critical speech and audio material. Moreover, the results suggest that the performance given by the reference synthesizer is not significantly compromised when using a low-complexity FFT-based synthesizer. The companion paper (Part II) generalizes BCC analysis and synthesis for multichannel audio and proposes complete BCC schemes including quantization and coding. Part II also describes an alternative BCC scheme with flexible rendering capability at the decoder and proposes several applications for both BCC schemes. Index Terms-Audio coding, auditory filter bank, auditory scene synthesis, binaural source localization, coding of binaural spatial cues, spatial rendering. I. INTRODUCTION T HE data rate of traditional subband audio coders, such as AAC [1] and PAC [2], scales with the number of audio channels. If the channels are compressed independently, the data rate grows proportionally to the number of channels. Joint-channel coding techniques, such as "Sum-Difference Coding" [3], "Intensity Stereo Coding" (ISC) [4], and "Inter-Channel Prediction" [5] can reduce this growth rate. However, the resulting data rate for conventional stereophonic 1 material is still considerably higher than needed for representing the corresponding mono audio signal. Thus, the trade-off between audio bandwidth, coding artifacts, and number of channels Manuscript
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