Redza Azmil Bin Radzuan

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