Noise Meter - dB Sound Level

Noise Meter turns the iPhone microphone into a rough guide to how loud a place is. Tap Start and an arc gauge shows the level in decibels as it changes, colored green under 40 dB, yellow from 40 to 60, orange from 60 to 80 and red above 80. The highest value since you started stays on screen until you tap Reset. When you stop a reading that lasted five seconds or more, a summary appears with its average, its peak and how long it ran. The average is an energy average, the usual way noise levels are combined, so a few loud moments count for what they are. The last 50 readings stay on this phone, and the clock button opens the list with the loudest one shown at the top. A second by second graph of the reading you just took opens from its summary after a short ad you choose to watch. A reference card puts the numbers in context: a library sits under 40 dB, an office between 40 and 60, street traffic between 60 and 80, and a concert above 80. Sound is never recorded or sent anywhere. The meter reads the microphone level only while a reading is running. Values are approximate, vary by device and do not replace a calibrated sound level meter. Screens come in nine languages: English, Korean, Japanese, Simplified and Traditional Chinese, Spanish, French, German and Portuguese.