Greenacres, WA Land Info. Washington is the country's 18th largest agricultural state. In 2014, the agricultural sector contributed $7.53 billion to the Washington economy, or two percent of overall state GDP (placing it eighth among all U.S. states for the size of its farm economy).
Zero decibels is the threshold of human hearing, 40 to 50 decibels is normal for a peaceful neighborhood, 70 to 80 decibels is the level adjacent to a busy urban street or 50 feet from a major freeway, and 120 to 140 decibels is a typical level at which sound is painful.ero decibels is the threshold of human hearing, 40 to 50 decibels is normal for a peaceful neighborhood, 70 to 80 decibels is the level adjacent to a busy urban street or 50 feet from a major freeway, and 120 to 140 decibels is a typical level at which sound is painful.
The catch is that there are several decibel scales. Thus, in order to be meaningful, your audiologist indicates which decibel scale she used. The two most commonly used scales are the SPL (Sound Pressure Level) and the HL (Hearing Level) scales. Sound meters are calibrated in dB SPL. This makes total sense because the condenser microphones used in sound meters are sensitive to changes in sound pressure in the air, just as our ears are. In contrast, audiometers are calibrated in dB HL, not in dB SPL like you would think would be done.