A computer-implemented method for user-control input comprising: initialising an encoder module; monitoring, using at least one sensor (170, 171), an extent to which a plurality of specific muscles, located, at least partially, within a face, head, neck, and/or shoulders, of the user (100, 140) are contracted and thereby derive a plurality of muscle-specific measurements, wherein the plurality of muscle-specific measurements of the user is representative of a muscle-contraction coded signal produced by the user; quantizing, by the encoder module, the plurality of muscle-specific measurements by assigning to it a plurality of muscle-specific numeric scores (111, 112, 113L, 113R, 114, 115, 116, 117) indicative of the extent of contraction of the at least one specific muscle with respect to a maximum possible contraction of the at least one specific muscle; combining the plurality of muscle-specific numeric scores (111, 112, 113L, 113R, 114, 115, 116, 117) into a composite number (132, 145) corresponding to the plurality of muscle-specific numeric scores; converting the composite number (132, 145) into a specific value (134, 149) indicative of a user input function to control a computing device; and using the specific value (134, 149) to control functions of the computing device (136, 150) based on the user input function; characterized in that the encoder module is initialised with a user configuration file specifying which signal features the particular user has elected, and a ranked order of said signal features, wherein some of the signal features are ranked as lowest-order bits; and the composite number is based on the signal features ranked at the lowest-order bits. initialising an encoder module; monitoring, using at least one sensor (170, 171), an extent to which a plurality of specific muscles, located, at least partially, within a face, head, neck, and/or shoulders, of the user (100, 140) are contracted and thereby derive a plurality of muscle-specific measurements, wherein the plurality of muscle-specific measurements of the user is representative of a muscle-contraction coded signal produced by the user; quantizing, by the encoder module, the plurality of muscle-specific measurements by assigning to it a plurality of muscle-specific numeric scores (111, 112, 113L, 113R, 114, 115, 116, 117) indicative of the extent of contraction of the at least one specific muscle with respect to a maximum possible contraction of the at least one specific muscle; combining the plurality of muscle-specific numeric scores (111, 112, 113L, 113R, 114, 115, 116, 117) into a composite number (132, 145) corresponding to the plurality of muscle-specific numeric scores; converting the composite number (132, 145) into a specific value (134, 149) indicative of a user input function to control a computing device; and using the specific value (134, 149) to control functions of the computing device (136, 150) based on the user input function; characterized in that the encoder module is initialised with a user configuration file specifying which signal features the particular user has elected, and a ranked order of said signal features, wherein some of the signal features are ranked as lowest-order bits; and the composite number is based on the signal features ranked at the lowest-order bits.