How to Break a Glass with Your Voice

The cassette tape company Memorex seared the image of Ella Fitzgerald shattering a glass with her voice into many people’s collective memory in a television commercial that ran in the 1980s. With the right tools, good pitch, and a strong voice (or anamplifier), you can do this at home.


With Amplification

1. Put on Safety Goggles to protect your eyes when the glass shatters. Use ear protection to protect your ears.

2. Plug your microphone into an amplifier.

3. Turn on your microphone and turn the volume on your amplifier to a high level.

4. Place a crystal glass (see Tips) right in front of the speaker of the amplifier.

5. Tap the glass and listen carefully to the ringing sound. You can also moisten your finger and rub the tip along the rim until the glass hums. Make note of this pitch and use it as a starting point in the next step.
6. Sing several different high notes into the microphone until you hit the right one for that specific glass. At that point, the glass will shatter.

7. Make sure to carefully dispose of the glass. Wear gloves when cleaning up to minimize cuts and scrapes.

Without Amplification

1. Put on safety goggles to protect your eyes when the glass shatters.

2. Put your lips almost directly against the glass. This is not necessary, as your mouth can be several inches away, but the closer you get the more focused the tone of your voice will be.

3. Sing at the same pitch found to break the glass with the previous method, and sing powerfully – cheap glasses will break at a lower decibel, such as 80-90 decibels. The glasses used on MythBusters were very expensive hard titanium crystal glasses, more amplification (roughly 105+ decibels) was needed to break the glasses.

4. Make sure to carefully dispose of the glass. Wear gloves when cleaning up to minimize cuts and scrapes.


  • The key is to replicate the frequency that is created when you lightly strike the glass, known as the “resonant frequency”.[1] The ringing sound is caused by the glass vibrating. If you sing at the same frequency, and you sing loudly enough, you can make the glass vibrate to the degree that the glass shatters.[2]
  • It’s easier to do this with crystal than with other types of glass.[3] The glass in windowpanes and cheap cups is “soft”, vibrates poorly and doesn’t have a nice sound to it, whereas crystal vibrates well, emits a clear tone when tapped, is stronger because of the added lead oxide, and enhances sound frequency with its shape.[4]
  • Every glass is different and has a unique breaking frequency.[4] A pitch that works with one glass probably won’t work with another.
  • The TV show Mythbusters recommends your tune sliding slowly up or slowly down.[5]
  • Also demonstrated on Mythbusters, placing a straw in the glass will help you see that it is indeed vibrating, and will aid you in hitting the right pitch.
  • A trick to hear a continuous tone of the resonant frequency: Wet your fingertip with water and rub around the edge of the glass in a continuous circular motion, eventually you will hear a continuous tone which happens to be the resonant frequency of this particular glass. It’s up to you to match or double (octave up) or half (octave down) this frequency.


  • Breaking a glass with your voice without amplification is extremely difficult. In a Mythbusters TV episode, professional vocal coach, Jaime Vendera was able to demonstrate the technique, after several attempts. Since the MythBusters show, Vendera has mastered the technique and has shattered ninety-eight glasses by voice alone including five in a row and two at once. He has also demonstrated this amazing ability on shows around the world, including more shows in the US, Europe and Japan.
  • Turning your amplifier up to max risks damaging the amp and your speakers, as well as your eardrums if you do not have them covered.
  • Be careful to avoid flying glass. Jaime Vendera has been cut by glass when screaming, so be very very careful.
  • Make sure to clean all glass bits when your done.

Things You’ll Need

  • A crystal glass
  • Glass in Fiber
  • Protective goggles
  • Ear Protection (ear plugs, ear muffs)

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This entry was posted on Monday, January 9th, 2012 at 9:13 pm and is filed under Entertainment. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.