Music examiners will play a note for their pupils, followed by a second note, and then ask them what the interval between them is. It is difficult to perfect this on our own, but we could 'employ' another in our household to assist us.
Surprisingly having a particular song in your head, can often help you to accurately pitch the start point.
See this post
http://www.ar-group.org/smforum/index.php?topic=3740.0Then you can continue with perfect pitch experiments.
As your note memory improves, try moving a few intervals up the musical scale.
Try humming your reference pitch, then hum the correct note a third above it.
Then a fifith, and so on.
This link to Tonic Solfa, will help you to cement relative pitches in your mind.
http://www.ar-group.org/smforum/index.php?topic=3720.0This type of practice is the key to learning relative pitch and will assist in developing your ability to possibly have perfect pitch.
Although perfect pitch is a great ability to have, it is something that you will need to spend hours of training to master, and actually it will not be as useful as you might think.
This is particularly true when compared with the easier to master, relative pitch
Before starting to spend time on perfect pitch, think about how it could benefit your music and especially consider in what ways you would use it.
If you still wanted to proceed, then select a reference pitch and with dedicated practice and repetition, you might achieve your goal.
This completes this Pearl.
Have you been working to perfect your pitch skills?
How are you training your ear?
Do you have perfect pitch?
How do you use it?
Please feel free to share your progress/experience in a reply below.
Peter