Is there a consensus that we have a possible vast range of actual causes (not theories) here? Sympathetic vibration will be temporary. The recent report of the lady in the old house. Think of a local substation generating a subsonic eddy current caused vibration pumping inaudible sound through the earth which is picked up by an old house that has aged lime mortar with lots of voids and you have a frequency changing loudspeaker. All for free. The effect will last for an unknown period as the voids will start to change as they "shake". The frequency only needs to slightly change for the hum to stop. The conclusion.. Modern life. The age related effect? The older we get our hearing ability changes and we always lose the high frequencies first, then we start to lose the lower frequencies,and then followed by deafness.
Julian Berg Giesecke & Devrient GB Ltd. Globe House, Unit One, Westlinks, Alperton Lane, Wembley, Middlesex HA0 1ER Registered in England & Wales: Company Number 3402266 -- You received this message because you are subscribed to the Google Groups "Hum Sufferers" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/hum-sufferers?hl=en.
