Apparatus for detecting an event of sleep disordered breathing of a user, the apparatus comprising: a sound sensor configured to detect sound proximate to the sensor; and a processor coupled with the sound sensor, the processor configured to perform a method for detecting an event of sleep disordered breathing of a user, the method comprising: receiving, in the processor, an input audio signal representing sounds of the user during a period of sleep; determining, in the processor, from the received input audio signal, at least one reliable respiration epoch, wherein a period of an input audio signal is classified as RRE based on whether the period includes a plurality of sections respectively satisfying a start section criteria and a middle section criteria; detecting, in the processor and based on data in at least one determined RRE, presence of a sleep disordered breathing event; and outputting, from the processor, an indicator of the detected sleep disordered breathing event, wherein each RRE comprises a start section satisfying the start section criteria and an event detection section satisfying the middle section criteria, characterised in that the start section criteria comprises a period of consistent audible breathing; wherein the processor is configured to: (a) distinguish signal types in the input audio signal by distinguishing a signal type comprising a snoring signal type or a breathing signal type, and (b) split the input audio signal into frames, wherein to determine the at least one RRE, each frame of a plurality of frames of the input audio signal is analysed to determine if signal levels of a current frame commenced after a predetermined number of seconds of repetitive and uninterrupted breathing or snoring signals determined from signal levels of one or more preceding frames; and wherein the uninterrupted breathing or snoring signals do not comprise gaps considered an apnoea or a loss of signal. a sound sensor configured to detect sound proximate to the sensor; and a processor coupled with the sound sensor, the processor configured to perform a method for detecting an event of sleep disordered breathing of a user, the method comprising: receiving, in the processor, an input audio signal representing sounds of the user during a period of sleep; determining, in the processor, from the received input audio signal, at least one reliable respiration epoch, wherein a period of an input audio signal is classified as RRE based on whether the period includes a plurality of sections respectively satisfying a start section criteria and a middle section criteria; detecting, in the processor and based on data in at least one determined RRE, presence of a sleep disordered breathing event; and outputting, from the processor, an indicator of the detected sleep disordered breathing event, receiving, in the processor, an input audio signal representing sounds of the user during a period of sleep; determining, in the processor, from the received input audio signal, at least one reliable respiration epoch, wherein a period of an input audio signal is classified as RRE based on whether the period includes a plurality of sections respectively satisfying a start section criteria and a middle section criteria; detecting, in the processor and based on data in at least one determined RRE, presence of a sleep disordered breathing event; and outputting, from the processor, an indicator of the detected sleep disordered breathing event, wherein each RRE comprises a start section satisfying the start section criteria and an event detection section satisfying the middle section criteria, characterised in that the start section criteria comprises a period of consistent audible breathing; wherein the processor is configured to: (a) distinguish signal types in the input audio signal by distinguishing a signal type comprising a snoring signal type or a breathing signal type, and (b) split the input audio signal into frames, wherein to determine the at least one RRE, each frame of a plurality of frames of the input audio signal is analysed to determine if signal levels of a current frame commenced after a predetermined number of seconds of repetitive and uninterrupted breathing or snoring signals determined from signal levels of one or more preceding frames; and wherein the uninterrupted breathing or snoring signals do not comprise gaps considered an apnoea or a loss of signal.