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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Below are some examples of prices by the square foot for common floor cleaning services: 1  Carpet cleaning - $.10 to $.25 per square foot. 2  Carpet spot cleaning/stain removal - $20 to $40 per hour.3  Stripping and waxing floors - $.20 to $.40 per square foot. professional floor cleaning service can keep your floors in like-new condition, removing day-to-day buildup of dirt and the scratches and scuffs that accumulate over time. Professional services handle all types of floors in all types of businesses, from major corporations to tiny retail shops.