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.
1 High-End Estimate: $0.30 per square foot (for homes with less square footage of carpet to clean). 2  Typical costs (without any add-on services) will average about $100 - $500 per carpet cleaning. Some companies will charge by the room (usually $15 - $40 per /room) or will give you one flat rate for a certain number of rooms in the house (including hallways and stairs). 2  Ask the company if they are running any specials for entire-house carpet cleanings.