What is sound level?

How is sound level measured?

What is Custom Calibration?

How to setup SoundMeter+ for Custom Calibration?

How do we feel when sound level increases?

What are the typical sound levels of musical instruments?

 

 

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What is sound level?

Sound level is the air pressure of a sound relative to a reference pressure. It is measured in decibels (dB) above the reference pressure that is 20 µPa.

On dB scale, if sound level increases by 10 dB, it will sound twice as loud to ears.

The humming of refrigerator is 45 dB, normal conversation is approximately 60 dB, whereas the noise of heavy traffic can reach 85 dB.

Sources that may cause hearing loss include: motorcycles, firecrackers, and firearms, all emitting sounds from 90 to 140 dB.

 

 

What is Custom Calibration?

By default, SoundMeter+ relies on a built-in microphone of iPhone, iPad, or iPod Touch to measure sound level. Meanwhile, SoundMeter+ uses its own accurate and complete library of factory calibration.

However, in the following cases, user may prefer to custom calibrate SoundMeter+:

Use an external microphone for measurement.

Compensate for temperature and humidity conditions that may slightly affect measurement.

Compensate for aging of electronic components that may slightly affect measurement.

Compensate for any future Apple iOS versions that may preset microphone input gain differently.

Other reasons that user feels appropriate.

 

 

How to setup SoundMeter+ for Custom Calibration?

First, please find a reference sound level for calibration. The reference level can come from sound calibrator, the reading of another sound level meter, or other known sound sources.

Then, follow simple steps:

1. Press "Custom Calibration" button on "Average Level" Panel of SoundMeter+.

2. A calibration window pops up. Follow instructions shown on window.

3. Press "Done" button to finish. User's calibration result automatically becomes effective in SoundMeter+.

Note:

"Custom Calibration" button indicates "ON" after calibration result is effective.

Toggling "Custom Calibration" button also turns "ON/OFF" custom calibration mode.

 

 

How do we feel when sound level increases?

           Perceptions                     vs.           Increases in Decibel (dB)
Unnoticeable 1 dB
Barely Noticeable 3 dB
Clearly Noticeable 5 dB
Twice as Loud 10 dB
Four Times as Loud 20 dB

 

 

What are the typical sound levels of musical instruments?

Sound Levels of Musical Instruments
Normal piano 60 -70dB
Violin 82 - 92dB
Piano peak 84 - 103dB
Cello 85 - 111dB
Clarinet 85 - 114dB
Horn 90 - 106dB
Flute  92 - 103dB
Oboe 95 - 112dB
Bass drum 106dB
Symphonic music peak 120 - 137dB
Rock, 5 feet away 120dB
Rock music peak 150dB