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.
Carpet cleaning prices range from approximately 15 to 35 cents per square foot, depending on the size and condition of the carpet. If you can do a good job cleaning a 1,300-square-foot house in three hours and need $100 per hour for your cost structure, a price of around 25 cents a square foot is a good bid.As your experience grows and your time per job improves, adjust your bids to stay competitive and consistently turn a profit.f you can do a good job cleaning a 1,300-square-foot house in three hours and need $100 per hour for your cost structure, a price of around 25 cents a square foot is a good bid. As your experience grows and your time per job improves, adjust your bids to stay competitive and consistently turn a profit.