What are NRC / STC? Why do tradespeople and homeowners need to know?

What are NRC / STC? Why do technicians and homeowners need to know?

Have you ever wondered why in some rooms normal conversation results in annoying echoes, while other rooms are perfectly silent as if no one is there?

Here's why

• NRC (Noise Reduction Coefficient) – is a value that indicates how well a wall or material absorbs sound
  
  

• Value from 0.0–1.0

  
  

• Higher value → Better sound absorption

  
  

• Use acoustic panels for walls, Mineral Fiber suspended ceilings

  
  

• Suitable for music practice rooms, meeting rooms, bedrooms

  

  STC (Sound Transmission Class) is a value that indicates how well a wall or door blocks sound from an adjacent room.

  
  

  • Value from 25–50

    
    

  • Higher value → Less sound penetration through walls

  • Room walls, doors, bricks, windows, glass

  • Suitable for quiet areas, offices, meeting rooms

    
    

    
    

    Why is it important to know?
    Choosing the wrong materials → Echoes and noise fill the house
    Choosing the right materials → A peaceful home for listening to music, relaxing, or working comfortably
    
    

    In simple terms

    • NRC = Reduces echo in a room
      
      

    • STC = Reduces sound transfer between rooms
      
      

    Before installing or building a room… knowing these values will help create a quiet, comfortable home and ensure cost-effective use of materials.