A device, comprising: a processor; a memory; wherein the memory includes programming instructions which when executed by the processor perform an operation, the operation includes: detecting a relative position of two earphones when connected to the device; determining if a binaural signal processing mode is appropriate based on the detected relative position and switching to the binaural signal processing mode, wherein if it is determined that the binaural signal processing mode is not appropriate, switching to monaural processing mode; wherein detecting the relative position includes detecting if an input signal frame contains speech and a source of the speech is localized around the mouth of a user of the device by measuring similarity of two waveforms captured by the two earphones as a function of a time-lag applied to one of the two waveforms, and if the source cannot be localized to the spatial region around the mouth, detecting if a source of the signal frame is localized about a user's head by using a head model which approximates the head-related transfer function from sources at different angular locations about the head. a processor; a memory; wherein the memory includes programming instructions which when executed by the processor perform an operation, the operation includes: detecting a relative position of two earphones when connected to the device; determining if a binaural signal processing mode is appropriate based on the detected relative position and switching to the binaural signal processing mode, wherein if it is determined that the binaural signal processing mode is not appropriate, switching to monaural processing mode; wherein detecting the relative position includes detecting if an input signal frame contains speech and a source of the speech is localized around the mouth of a user of the device by measuring similarity of two waveforms captured by the two earphones as a function of a time-lag applied to one of the two waveforms, and if the source cannot be localized to the spatial region around the mouth, detecting if a source of the signal frame is localized about a user's head by using a head model which approximates the head-related transfer function from sources at different angular locations about the head. detecting a relative position of two earphones when connected to the device; determining if a binaural signal processing mode is appropriate based on the detected relative position and switching to the binaural signal processing mode, wherein if it is determined that the binaural signal processing mode is not appropriate, switching to monaural processing mode; wherein detecting the relative position includes detecting if an input signal frame contains speech and a source of the speech is localized around the mouth of a user of the device by measuring similarity of two waveforms captured by the two earphones as a function of a time-lag applied to one of the two waveforms, and if the source cannot be localized to the spatial region around the mouth, detecting if a source of the signal frame is localized about a user's head by using a head model which approximates the head-related transfer function from sources at different angular locations about the head.