What do you do when someone tells you you're singing flat, even though to your own ear your singing is perfectly in tune?
Let's rule out the possibility that there's actually something wrong with your ear (if all else fails, you'll need to investigate that with your doctor later). Your ear is probably doing its job very well. Its job is to tune your vocal folds by stretching them to the length that will produce the desired pitch; this done, you will hear the fundamental pitch you intended.
However, the length of your vocal folds is not the only thing that determines how others perceive the pitch you are producing. Several factors can result in inadequate resonance and/or an incomplete spectrum of overtones, leading to your pitch sounding flat to the listener:
- Over-heavy registration;
- Insufficient air flow;
- Insufficient resonance space. Resonance is nearly as important for tuning your voice as the actual length of the vocal folds.
If any or all of these things are happening, you may not perceive how they're impacting your intonation. So if someone tells you you're singing flat, don't panic and don't just try to push your pitch up - it will then probably sound sharp to you and tighten up your voice. Instead, trouble-shoot these three things and see whether that helps.
And when giving feedback to your colleagues, be as kind and helpful as possible. No one wants to sing flat, but no one enjoys hearing about it either!