Sounds similar to 'Musical ear syndrome': https://en.wikipedia.org/wiki/Musical_ear_syndrome https://en.wikipedia.org/wiki/Musical_ear_syndrome Unfortunately m

Sounds similar to 'Musical ear syndrome': https://en.wikipedia.org/wiki/Musical_ear_syndrome https://en.wikipedia.org/wiki/Musical_ear_syndrome Unfortunately most of the proposed causes seem pretty speculative to me. Good old "brain searching for a pattern" seems like the obvious one to reach for. Fortunately it seems to be relatively common (although it is disconcerting). I've been experiencing this recently and I swear I can hear AM band radio. Interestingly, the 'white noise' backdrop for these 'phantom sounds' is generated by one of 2 machines in my house: an air purifier and an aircon unit. Even more interesting is that both have air-ionisers built in to them for air purification purposes (negative ions from the purifier, unclear what's in the A/C). At the risk of sounding a little crazy, I wonder if there's possibly a connection... EDIT: If there was something to this, it would certainly give more meaning to the phrase 'babbling brook' (i.e. breaking water negatively ionises the surrounding area). I know that sounds up there with other hippy-science like 'crystal healing', but take a look at [1] & [2]. [1] http://www.webmd.com/balance/features/negative-ions-create-positive-vibes#1 http://www.webmd.com/balance/features/negative-ions-create-p... [2] https://en.wikipedia.org/wiki/Negative_air_ionization_therapy#Mechanism https://en.wikipedia.org/wiki/Negative_air_ionization_therap...