A method of providing stability in an active noise reduction headphone, the ANR headphone comprising a feed-back ANR signal pathway comprising a feed-back microphone, a first variable gain amplifier, and a first filter, and a feed-forward ANR signal pathway comprising a feed-forward microphone, a second variable gain amplifier and a second filter, the method comprising: measuring a sound field to generate a first input signal; characterized in that: in an ANR signal pathway (202,204) among the feed-back ANR signal pathway and the feed-forward ANR signal pathway comprising a first side-chain loop (206,208), filtering and applying a variable gain to the first input signal to produce a first filtered signal using the first filter and the first variable gain amplifier, or the second filter and the second variable gain amplifier, respectively; outputting the first filtered signal; and simultaneously with outputting the first filtered signal, the first side-chain loop sampling the first filtered signal and filtering the sampled signal using a third filter (210,212) to produce a second filtered signal; comparing the second filtered signal to a predetermined threshold (214,216) set to check instability in the ANR signal pathway; and if the comparison finds that the second filtered signal is greater than the threshold signal, changing the gain of the first or second variable gain amplifier with the first side chain loop to attenuate the first filtered signal; wherein the third filter applies first and second gains in respective first and second frequency ranges between 10 Hz and 10 kHz, the first and second gains being different by at least 6 dB. in an ANR signal pathway (202,204) among the feed-back ANR signal pathway and the feed-forward ANR signal pathway comprising a first side-chain loop (206,208), filtering and applying a variable gain to the first input signal to produce a first filtered signal using the first filter and the first variable gain amplifier, or the second filter and the second variable gain amplifier, respectively; outputting the first filtered signal; and simultaneously with outputting the first filtered signal, the first side-chain loop sampling the first filtered signal and filtering the sampled signal using a third filter (210,212) to produce a second filtered signal; comparing the second filtered signal to a predetermined threshold (214,216) set to check instability in the ANR signal pathway; and if the comparison finds that the second filtered signal is greater than the threshold signal, changing the gain of the first or second variable gain amplifier with the first side chain loop to attenuate the first filtered signal; wherein the third filter applies first and second gains in respective first and second frequency ranges between 10 Hz and 10 kHz, the first and second gains being different by at least 6 dB. the first side-chain loop sampling the first filtered signal and filtering the sampled signal using a third filter (210,212) to produce a second filtered signal; comparing the second filtered signal to a predetermined threshold (214,216) set to check instability in the ANR signal pathway; and if the comparison finds that the second filtered signal is greater than the threshold signal, changing the gain of the first or second variable gain amplifier with the first side chain loop to attenuate the first filtered signal; wherein the third filter applies first and second gains in respective first and second frequency ranges between 10 Hz and 10 kHz, the first and second gains being different by at least 6 dB.