REDZA AZMIL BIN RADZUAN 08DPB06F534 (DPB6A)
Perception of sound For humans, hearing is normally limited to frequencies between about 12 Hz and 20,000 Hz (20 kHz)[2], although these limits are not definite. The upper limit generally decreases with age. Other species have a different range of hearing. For example, dogs can perceive vibrations higher than 20 kHz. As a signal perceived by one of the major senses, sound is used by many species for detecting danger, navigation, predation, and communication. Earth's atmosphere, water, and virtually any physical phenomenon, such as fire, rain, wind, surf, or earthquake, produces (and is characterized by) its unique sounds. Many species, such as frogs, birds, marine and terrestrial mammals, have also developed special organs to produce sound. In some species, these have evolved to produce song and speech. Furthermore, humans have developed culture and technology (such as music, telephone and radio) that allows them to generate, record, transmit, and broadcast sound
Longitudinal and transverse waves
Sound Meter Level
The Galaxy CM-130 Check Mate SPL Meter provides instant, accurate dB readouts when you have to comply with noise codes. The CM-130 sound meter is useful in the studio to establish critical monitoring levels. 4 level ranges. Includes an electric condenser microphone. To measure sound output of our acoustic drum kit, both with and without shield that built. It works great! it also use to locate 'hot spots' in the worship center when band is playing through the house system. It will read out bass-weighted dB, overall dB, and peak dB at the push of a button. It also can choose slow vs. fast sampling to see what an 'average' dB is versus watching the level jump & and down.
Technical specifications Galaxy CM-130 Check Mate SPL Meter Features: • • • •
Mini size MAX function Level range display Resolution 0.5dB
Galaxy CM-130 Check Mate SPL Meter Specifications: • • • • • • • • • • • • • • •
Microphone: 1/2 electret condenser microphone Accuracy: ±2dB (under reference conditions 94dB @ 1kHz) Level Range: 1= 40~70 dB 2= 60~90 dB 3= 80~110 dB 4= 100~130 dB Frequency weighting: A, C Time weighting: Fast, Slow Dynamic range: 30 dB Frequency range: 125Hz to 8kHz Battery life: 9V battery 110 hours (Included) Operation Temp: 0 degrees C - 140 degrees C (32 degrees -104 degrees F) Storage Temp: -10 degrees C - 60 degrees C (14 degrees -140 degrees F) Dimensions: 9.1" x 2.1" x 1.3" (232mm x 54mm x 34mm) Weight: Approx. 0.37 lbs (170g) (including battery)
Dimensions Product Length
6.25 inches
Product Height
1.75 inches
Product Width
2.5 inches
Product Weight
5.8 ounces
Examples of sound pressure and sound pressure levels
Source of sound
RMS sound pressure sound pressure level
Pa
Theoretical limit for undistorted sound at 1 atmosphere environmental pressure
dB re 20 µPa
101,325
1883 Krakatoa eruption
approx 180 at 100 miles
Stun grenades
170-180
rocket launch equipment acoustic tests
threshold of pain
hearing damage during short-term effect
jet engine, 100 m distant
jackhammer, 1 m distant / discotheque
hearing damage from long-term exposure
traffic noise on major road, 10 m distant
191
approx. 165
100
134
20
approx. 120
6–200
110–140
2
approx. 100
0.6
approx. 85
0.2–0.6
80–90