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.
Get started now! 1  Commercial carpet cleaning costs between $.05 and $.20 per square foot. 2  You can rent Rug Doctor carpet cleaning machines for $25 to $40 for 24 hours from many locations. 3  You can buy carpet steam cleaners starting at around $150.
Best Answer: The national average price for carpet cleaning is about 22 cents per square foot. That usually means each room is about $30 - $40 to clean. The following is the cost of cleaning 3 bedrooms and a hall from three different carpet cleaning companies (Estimates were calculated on their websites). Stanley Steemer = $138. Chem Dry = $140.