The above quote is a chinese proverb. Its been widely accepted – we absorb information best by using multiple senses. Make your impressions visual, verbal and auditory. I was not able to verify this study but there are several references to a study done at the University of Texas that found that people remember (Metcalf 1997):
10 percent of what they read;
20 percent of what they hear;
30 percent of what they see;
50 percent of what they see and hear;
70 percent of what they say; and
90 percent of what they do and say