Currently, most user interfaces fall into one of two categories, which can be called “Discrete Control Interfaces (DCI)” which use a set of discrete switches which can register an on or off position to enable simple discrete inputs, and “Continuous Action Interfaces (CAI)”, which register spatial, pressure-based, or gestural movement in time to enable more complex inputs based on continuous movement. DCI include keyboards, keypads, and other interfaces that use direct analog (usually switch-based) controls that usually simulate a mechanical action, while CAI include touch screens, touchpads, other two-dimensional touch sensitive interfaces using e.g. a plurality of pressure sensors, and devices like a computer mouse, which use a rolling ball or some other continuous action apparatus that allows for continuous input.
The advantages of DCI interfaces are (1) that they allow for clear discrete inputs, and (2) that they typically form a tactile input feedback system and thus do not rely on visual confirmation. In other words, they provide clear separate commands, and they give the user tactile information about which commands have registered, since the user can feel a responding pressure when he depresses a key, for example. These advantages relate not just to the kind of sensing device but also to the design of the input surface, the topmost part of the interface with which the user actually interacts. Such DCI interfaces are particularly useful for music controllers as each key provided on the interface may allow a function such as producing an audio signal corresponding to a present note. A dial provided on the same interface may further allow modulation of the audio signal properties when played, the modulation for instance altering the pitch, the frequency or characteristics of a filter or applied function.
Such controllers presenting a DCI interface with a plurality of interactive elements are usage specific, i.e. dedicated controllers. They remain costly and complex to manufacture considering the variety of different connections and mechanisms necessary to enable the different functions.
Document US2013239787 describes an example of a controller with a DCI interface as shown in FIG. 1. This DCI interface presents as many as four different types of interactive elements. A plurality of pressure and position sensitive pads 102 is provided to elicit audio signals such as drums or percussion sounds. Additional switches 104, rotary sensors or knobs 106 and faders 108 are also provided to modulate the audio signals resulting from a tactile input on one or more of the pads 102. A user interested in modulating a drum beat will have to manipulate different switches, knobs, dials and/or sliders to produce a modulated sound.
Beyond the complexity of manufacturing, the disadvantage of DCIs is that the user is the limited in the types of input that can be made, especially when the goal is to input quantitative or continuous information, as opposed to qualitatively separate, distinct commands.
There is still a need today for a music controller that allows complex control over an audio signal with a simple user experience to produce a variety of musical effects.