Once you're certain the Microphone is working, here is how you can obtain the best results...
Microphone placement
Place the microphone near the sound source, but not too close. The microphone should generally be placed as near to the sound source as possible. However, singing too close to a microphone may create "popping" effects. A good starting point is about 2 feet. Avoid handling the microphone, because it introduces rattling noises.
◊
Inspect the Volume Level Indicator.
Verify that the speaker icon is active. The number of bars emanating from the speaker icon indicates volume level. Say 'Hello' while watching the speaker icon. Bars should emanate from the speaker, then vanish again. If not, go to the Microphone Configure dialog and adjust the Microphone Input Level.
Automatic Gain Control
Some Macintosh's employ an Automatic Gain Control (AGC) circuit that continuously adjusts the input volume level, electronically. If given the option, turn AGC on.
Background Noise
Excessive background noise can affect pitch detection. Sometimes the source of background noise is not obvious. For example, a washing machine or air conditioner may create a low-frequency rumbling which is evaluated by the Perfect Pitch‚Ñ¢ algorithm. If the volume indicator bars are lit even when you stop tuning, your environment may be too noisy, even if you can't hear it.
One Note Only!
Perfect Pitch‚Ñ¢ can only detect one note at a time! It cannot distinguish individual notes among chords. When using an instrument capable of producing more than one note, avoid notes which continue to sound after a new note is introduced. For example, avoid the sustain pedal when playing the piano, or 'open' strings on a guitar. For the same reason, avoid reverb and echo effects added to your voice or instrument.
CPU Hog
The Perfect Pitch‚Ñ¢ detection algorithm requires a lot of the available CPU processing time. Try to keep background processing to a minimum. Close other applications if possible, since some applications which use sound may compete for sound resources.