Noise cancellation for balance prosthesis

A method comprising:

• receiving first signals having a first component indicative of first movements of a head of a recipient in a first frequency range and a second component indicative of second movements of the head in a second frequency range;
• receiving second signals at least partially indicative of the second movements;
• and
• generating third signals by adaptively filtering the first signals in response, at least in part, to the second signals, the third signals indicative of the first signals with the second component suppressed.

A method comprising:

• receiving at least one first orientation signal from a first sensor array comprising at least one first accelerometer, the at least one first orientation signal indicative of a direction of gravity relative to a first coordinate system of the first sensor array;
• receiving at least one second orientation signal from a second sensor array comprising at least one second accelerometer spaced from the at least one first accelerometer, the at least one second orientation signal indicative of the direction of gravity relative to a second coordinate system of the second sensor array;
• determining, in response to the at least one first orientation signal and the at least one second orientation signal, a relative orientation between the first coordinate system and the second coordinate system;
• and
• using the relative orientation to transform first motion signals received from the first sensor array indicative of motion of the first sensor array relative to the first coordinate system and/or to transform second motion signals received from the second sensor array indicative of motion of the second sensor array relative to the second coordinate system such that the first motion signals and the second motion signals correspond to motions of the first sensor array and the second sensor array, respectively, relative to a common coordinate system.