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 Kitchen cleaning runs $50 to $150 per hour, depending on the size of the crew and the level of deep cleaning that is required. 2  This is usually only necessary a few times each year.3  Professional carpet cleaning costs $.05 to $.25 per square foot.estaurant Cleaning Service Average Costs. The cost of hiring a restaurant cleaning service can be just a few hundred dollars a month for light cleaning tasks such as dusting, vacuuming, and cleaning the bathrooms.