Turning Up the Volume
The difference threshold is the amount of stimulus change needed to recognize that a change has occurred. If someone changes the volume of a speaker, the difference threshold is the amount it has to be changed in order for listeners to notice a difference.
Source
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"turn the music up | Flickr - Photo Sharing!."
http://www.flickr.com/photos/melloveschallah/4806752364/in/photolist-8jKS1L-8nx9AH-8RPYid-axUEqt-8RCVcn-baYq8i-ddSFnF-8hwv6H-dtHqjw-em8t2w-ecdUyL-bh8GEV-9tQdK6-8ooLtc-dQWKhi-8hVZyc-8bvWnw-97qmRc-9df9Rb-8quFW9-8thDyL-doFVfZ-8eh2jj-7USfbF-9ng8sk-abbytW-9pDiXD-aQyeiK-8fWyDv-duBP1e-7MpAyj-bKtUrV-fJCnN4-ftPooe-drUZo8-duWtaj-duWt8G-duWtgw-dkTzXr-82LxTy-amPjXJ-auJKzH-8w5ywj-9YVNGg-dTyuyp-agKiaB-agJS9B-a6XNu9-a6UUhr-8YWsyM-dXHt84/
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