Down the side of the audiogram, there is a measure of loudness. At the top of the graph are the very. quiet sounds, going down to moderate, and then very loud sounds. The points (red circles and blue. crosses) marked on the graph represent the quietest sound which can be just heard.
Steps. 1  1. Wait at least 3 days to wash newly permed hair, or your perm would not last as long. 2  2. Use hair care products that are safe for permed hair 3  . 3. Wash your hair gently (don't scrub too hard or your hair will tangle up)(your hair is very porous and fragile). 4  4. Gently rinse your hair.
And even though you may not see the curl anymore, be sure to tell a stylist that there is a previous perm in your hair, as the chemicals will still be lingering inside. Q- How long do I have to wait to wash my hair? A- Most stylists will recommend waiting 24 hours before washing your hair. The average perm needs at least 28 hours to fully neutralize and relax. I always recommend a full 48 hours before shampooing.