Abstract: In general, techniques are described for compensating for loudspeaker positions using hierarchical three-dimensional (3D) audio coding. An apparatus comprising or more processors may perform the techniques. The processors may be configured to perform a first transform that is based on a spherical wave model on a first set of audio channel information for a first geometry of speakers to generate a first hierarchical set of elements that describes a sound field. The processors may further be configured to perform a second transform in a frequency domain on the first hierarchical set of elements to generate a second set of audio channel information for a second geometry of speakers.

Abstract: Arrangements are described that may be used to reduce the intelligibility of speech using masker signals which are obfuscated yet correlated versions of the speech. Other applications of pitch analysis and demodulation are also described. A system may be used to drive an array of loudspeakers to produce a sound field that includes a source component, whose energy is concentrated along a first direction relative to the array, and a masking component that is based on an estimated intensity of the source component in a second direction that is different from the first direction.

Abstract: A method of analysing an audio signal is disclosed. A digital representation of an audio signal is received and a first output function is generated based on a response of a physiological model to the digital representation. At least one property of the first output function may be determined. One or more values are determined for use in analysing the audio signal, based on the determined property of the first output function.