User guide for check_audioLevels

Before the participant arrives:

• Run check_audioLevels in MATLAB
• Select choice a) that the mic and headphones are working, then check background noise levels (before participant arrives)
• Put on mic and headphones and speak
• Make sure you can hear your voice through the headphones
• Press space to continue
• The next screen will tell you to make sure the headphones are plugged in to the correct output of the headphone amplifier *  
• Use the audiometer/SPL meter to check the noise level
• The settings of the SPL meter should be set to: **
• No max or min
• A mode
• Slow
• Level 50-100 db
• Take the foam cover off of the SPL meter and place it inside the headphones
• The noise level should be about 60 db
• If it is not, adjust the appropriate headphone output knob on the headphone amplifier

• Run check_audioLevels in MATLAB
• Select b) the microphone level with the participant
• First, it will tell you to make sure the headphones are plugged in to the correct output of the headphone amplifier *
• Use the audiometer/SPL meter to check the noise level
  • The settings of the SPL meter should be set to: **
    
    • No max or min
    • A mode
    • Slow
    • Level 50-100 db
• Take the foam cover off of the SPL meter and place it inside the headphones
• Have the participant sustain the word "head" at a comfortable volume
• The noise level should be about 80 db
• If it is not, adjust the microphone gain (black knob) ***