Abstract: A method (300) of generating a pulse width modulation (PWM) signal for an analog amplifier, the amplifier arranged to receive an amplifier input signal having a magnitude, is disclosed. The method comprises receiving (302) a modulator input signal, which is associated with the amplifier input signal; and using (304) the modulator input signal to modulate a carrier to produce the PWM signal, wherein the carrier's frequency varies in dependence on the magnitude of the amplifier input signal. A related pulse width modulator is also disclosed.

Abstract: A versatile communications (comms) apparatus to provide a means to measure the audio (earphone) output of an electronic device (e.g. a music player in a smartphone), and/or to provide a means for wireless communications between a first electronic device (e.g. a smartphone) and a second electronic device (e.g. a hearing aid, pacemaker, etc). In some embodiments, the comms apparatus does not need power and in other embodiments, its power may be harvested from the first electronic device, or drawn from a battery that may be recharged by harvesting means or charged directly. The first electronic device typically includes an audio (earphone) output, a microphone input (with a voltage bias), a long-range communications transceiver (e.g. GSM), and where pertinent, a short-range transceiver (e.g. Bluetooth) and is internet enabled.