Is it really true dat if u scream loud enough u can break glasss??

cuz i always see it on t.v...like harry potter.Is it really true dat if u scream loud enough u can break glasss??
It's not the volume, it's the pitch that is important. If you are skilled enough to get the pitch to make the glass vibrate at a high enough frequency, the glass can be made to break. However, this is near impossible and takes much voice training.Is it really true dat if u scream loud enough u can break glasss??
don't believe everything you see
The other answerers are correct that it is the frequency, not the volume. Here is some more about this topic, though. Recently, on an episode of the Discovery Channel show ';Mythbusters'; they investigated this question. They said their researchers had been unable to find one clearly documented case of it happening. HOWEVER, they then found a voice coach whom they caught on film breaking a glass by singing at the right frequency. So, yes, it is true.
Its not screaming loud that does it. The sound you make has to be held at exactly the right pitch, not volume. Oh and try posting this in the science section you might get more detailed answers.
The issue is not the loudness of the scream but the frequency at which the molecules in the glass can vibrate until they shatter.