Mitsubishi Electric Lossnay LGH-F1200RX5-E, Техническое руководство

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U-43
CHAPTER 4
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Characteristics
4.3 Sound Frequency Analysis
The human ear detects sound differently according to the frequency; however, the sound generated from vibrations is not
limited to one frequency, but instead, various frequencies are generated at different levels. NC curve will show how the various
frequencies are generated at different levels, which is determined according to the difficulty of detecting conversations.
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Even if the sound is a very low level, it can be detected if it has a specific and loud frequency.
These sounds are low during product design stages, but sounds may become very disturbing if resonating on ceilings, walls,
etc.
Example: Continuous Frequency Analysis NC Curve
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Tolerable Sound Levels and NC Values According to Room Application
Frequency band (Hz)
Le
vel (dB)
Frequency (Hz)
SPL (dB)
Min. audible limit
Room Application dB NC Value Room Application dB NC Value
Broadcasting studio 25 15 - 20 Cinema 40 30
Music hall 30 20 Hospital 35 30
Theater (approx. 500 seats) 35 20 - 25 Library 40 30
Classroom 40 25 Small office 45 30 - 35
Conference room 40 25 Restaurant 50 45
Apartment 40 25 - 30 Gymnasium 55 50
Hotel 40 25 - 30 Large conference room 50 45
House (living room) 40 25 - 30 Factory 70 50 or more