The only bird known to make use of infrasound (at about 20 Hz) is the western capercaillie. The hearing range of birds is from below 50 Hz (infrasound) to around 12 kHz, with maximum sensitivity between 1 and 5 kHz. The range of frequencies at which birds call in an environment varies with the quality of habitat and the ambient sounds.
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Reports indicate tremendous savings in labor costs-the most expensive part of running a carpet cleaning business or managing a facility. As far as production rates, count on approximately 2,500 square feet of carpet cleaned per hour (depending on agitation method used), with a .003 cents per square foot chemical cost.However, prove it for yourself. You have to do your own math, with your own production team and procedure.eports indicate tremendous savings in labor costs-the most expensive part of running a carpet cleaning business or managing a facility. As far as production rates, count on approximately 2,500 square feet of carpet cleaned per hour (depending on agitation method used), with a .003 cents per square foot chemical cost.