In the 1970s, in a well-known advertisement in the United States, some singers broke glasses with just their voice. You might ask yourself, therefore, "Is it possible to break a glass with your voice?". While your success depends on many factors, if you put enough time and effort into this business, you may be able to shatter a glass with your voice.
Steps
Method 1 of 3: Prepare the Environment for the Glass Break
Step 1. Prepare the place where you will break the glass
Remember: if you are successful, you will produce broken glass, so practice in a room with a hard floor to make cleaning easier. Choose a space with good acoustics and no echo. If you have decided to use a microphone, you also need a power outlet to connect an amplifier, as well as a platform on which to place the glass and the electronic device.
- If you're going to break the glass with just your voice, you need a sturdy platform to set it on. The surface should be relatively high for you to stand upright while singing to produce optimum tone and volume.
- Spread a tarp on the floor if you want to try to break a glass in a carpeted room. Small shards of glass could get stuck in the hair on the floor and injure someone. Thanks to the tarpaulin this will not happen.
- When using the microphone and amplifier, you should face the device towards the glass and place it relatively close to it. A sturdy coffee table may be enough to hold the case and glass, limiting distorting vibrations. In the absence of alternatives, you can also place everything on the floor. Try to orient the amplifier so as not to disturb neighbors or other people.
- Place the glass directly in front of the amplifier speaker. Look through the material covering the front of the device and find the exact location of the cone of the case. Put the glass right in front of the cone.
Step 2. Put on safety glasses to protect your eyes
By shattering the glass you can produce very small splinters, which can cause permanent eye damage. Wearing simple eye protection this will not happen.
If you don't have goggles handy, you can use a pair of cheap sunglasses or swimming goggles. Make sure the protection covers the whole eye. In this case, reading half lenses are not suitable
Step 3. Find the resonant frequency of the glass
Gently tap the glass with your fingernail and listen carefully to the sound it produces. This is the resonant frequency of the glass, which you will need to reproduce exactly to shatter the glass. When the glass has stopped ringing, you can hum the note under your voice to remember it.
- You can produce the resonant frequency sound by moistening your finger and running it along the edge of the glass. Move your finger in a circle on the edge of the glass, until it resonates. Try memorizing that note.
- You may find that with the help of a musical instrument it will be easier to identify, maintain, and reproduce the resonant frequency with your voice.
- The glass must be completely empty, it must not contain decorations and must be placed on a flat and resistant surface, when you listen to its resonant frequency. Any objects found in or on the glass can alter this note.
Step 4. Remember the resonant frequency
By holding a note in your head for some time, you will almost always tone it down. Singing a note lower than the resonant frequency will not be able to break the glass. To avoid this problem, accompany yourself with a musical instrument or use a tuner. Recognizing very small differences in tone is difficult even for experienced players.
Check often the note you sing as you try to break the glass with your voice. Just hit the glass again with your fingernail, listen to the note produced and modulate the one you are singing, so that they are identical
Step 5. Try to produce the resonance note at a high volume
Usually, this feat is attempted by professional singers, who have great vocal power. To break a glass, in fact, you will have to reach a volume of at least 100-110 decibels and perfectly reproduce the resonant frequency with your voice. If you have not received training on this, this is a difficult undertaking. In that case, use the help of a microphone.
The volume of 100-110 decibels is that produced by a lawnmower, chainsaw or motorcycle. To break a glass you will have to reach or exceed that volume, singing the resonance note
Method 2 of 3: Break a Glass with Your Voice Alone
Step 1. Bring your mouth to the glass
With proper practice and sufficient vocal power you should be able to break a glass even from a greater distance. Most normal people, however, have a hard time sustaining the volume needed to accomplish this feat successfully. Getting close to the glass will concentrate the energy of the sound waves and have a higher chance of succeeding.
To check the volume of your voice, you can download an application capable of measuring the intensity of sounds on your phone from the app store, or you can buy a measurement tool on the internet. If you notice that even when you are producing maximum effort, you don't even get close to the required 100-110 decibels, you should use a microphone
Step 2. Sing the note of the resonant frequency
Start singing at normal volume. Listen carefully to the sound of your voice. Are you producing a note higher or lower than desired? In that case, make the necessary changes. When you are sure you are playing the note perfectly, slowly increase the volume, until you reach maximum power.
- If you feel discomfort, pain, or notice a noticeable change in the quality of your voice, it means that you are straining your vocal cords, singing too loudly or straining your voice for too long. To avoid permanent damage, you should stop immediately and drink some water. Don't start over until your voice has returned to normal.
- Vowel sounds are less obstructed, so they allow you to reach higher volumes. In particular, the "i" is the vowel that allows you to express the greatest vocal power. Even by singing the "e" it is possible to reach very high volumes.
- Keep singing the note for as long as possible, making the necessary changes. Even if you were able to reproduce the resonant frequency exactly, you would have to hold the note perfectly for a few seconds, before the glass vibrates enough to break. In most cases you will need to "rock" your voice slightly up and down, making small adjustments to produce the desired note.
Step 3. Try to break different glasses
Some glasses have more microscopic imperfections than others; the glass that has the most is more likely to shatter. By using multiple glasses, you should be able to find one with enough blemishes to break.
You can also try glasses of different shapes and sizes. Be sure to check the resonant frequency of each of them with a flick of the fingernail; each glass has a unique frequency
Step 4. Throw away the broken glass carefully if you have been successful
Wear gloves when cleaning to avoid cutting or scratching yourself with sharp glass. Examine the area carefully to make sure you have picked up even the smallest splinters. For this purpose, a flashlight can be useful to you.
Avoid using a vacuum cleaner to suck up glass splinters. You could damage the appliance. Instead, try to pick up as many splinters as possible with a broom, then catch the smaller ones by crushing them with a piece of bread
Method 3 of 3: Break Glass with a Microphone
Step 1. Protect your hearing
The amplifier will need to be set to a fairly high volume for your attempt to be successful, so you should protect your ears from potentially harmful noise levels. Earplugs may be sufficient, but if the volume is really very loud you will need special hearing protection.
Step 2. Prepare your amplifier
Plug the device into the power outlet and turn it on. You should hear a slight static noise caused by electricity passing through it; this means it is ready to receive input. Take the microphone cable and connect it to the amplifier.
- Keep the microphone as far away from the amplifier as possible to avoid distortion and backlash.
- If you can, use a microphone stand. Singing hands-free will allow you to focus only on the performance.
- Remember to wear protective eyewear. Also, to minimize exposure to loud noise, you should stay behind the amplifier.
- If the microphone doesn't work, check that it's turned on. If the device is already on, but it is not working, check that the jack is properly inserted into the amplifier.
Step 3. Adjust the volume of the amplifier
If you're using a device you don't know well, test its volume at medium level before setting it to full power. For almost all types of glass you will need to reach a minimum of 100-110 decibels, the volume of a motorcycle, a horn or music in a disco.
- You could line the wall your amplifier is facing with sound absorbing materials, such as heavy blankets or pillows. That way you won't bother other people.
- You can also use acoustic panels, sound absorbing curtains, or other techniques to muffle the sound.
Step 4. Sing into the microphone
Save your voice unnecessary strain by singing at low or medium volume. Swing your voice on notes very close to the resonant frequency, until it reproduces perfectly. At that point, turn up the volume until you sing directly into the microphone at medium power.
- If the glass doesn't break, use a tuner to check the note you produce. The margin of error is very minimal.
- Vowels are less obstructed sounds, so singing them will allow you to reach higher volumes. In particular, the "i" is the vowel that allows you to express the greatest vocal power. Even by singing the "e" it is possible to reach very high volumes.
- Keep singing the note for as long as possible, making the necessary changes. Even if you imitate the resonant frequency perfectly, you will still have to hold the note for a few seconds to get the glass to vibrate sufficiently and break.
- Since you are using an amplifier, you shouldn't be yelling into the microphone. Singing out loud will strain your vocal cords and may suffer permanent damage. Sing into the microphone at medium volume and pause whenever you hear your voice getting tired.
Step 5. Throw away the broken glass carefully if you have been successful
With a pair of rubber gloves you will avoid cuts and scratches during cleaning. You could use a flashlight to find all the fragments. Pick up and throw away the larger splinters with your hands, use a broom for the smaller ones, and be careful if you decide to use a vacuum cleaner. Glass fragments could cause damage to the appliance.
A common trick for picking up small shards of glass is to use a slice of fresh bread. Press the bread to the floor where you notice splinters. The glass should be collected from the bread and, thanks to this expedient, you will be able to remove it all. To clean a large area, you may need several slices of bread
Advice
- Always wear protective goggles to avoid eye injuries.
- If you have trouble playing a note with your voice after listening to it, you can take singing lessons before attempting to break a glass.
- Inexpensive glasses are easier to break, because their quality controls are often less rigid, consequently they contain more imperfections and the volume required to break them is lower.
- You can put a straw in the glass to notice when it vibrates. This way you will be able to find the right frequency.
- You can break the glass by singing its resonant frequency an octave higher (double the frequency) or lower (half the frequency).
- Each glass has a unique and different resonance frequency from the others. Imperfections invisible to the naked eye can cause a glass to resonate at a completely different resonant frequency from another apparently identical one.
- The American television program Mythbusters has conducted research on the breaking of glasses with the voice. The results of their experiments led presenters to suggest "rocking" the voice up and down when searching for the resonant frequency of the glass.
- Crystal glasses are better suited for this purpose than other types of glass.
- You can find the approximate resonant frequency and note you need to imitate by rubbing a damp finger along the edge of an empty glass. You should make the resonant frequency sound of the glass.
Warnings
- Broken glass can be dangerous. Be careful when trying to remove them.
- By setting the amplifier to maximum volume you can cause damage to the device itself, to the speakers and to your eardrums.
- Be careful to avoid flying glass shards. Heavy metal singer Jim Gillette was cut from glass while performing this experiment, so don't take any chances.
- Breaking a glass with unamplified voice is very difficult. In the beginning, you will almost certainly not be successful. With practice and training, however, you will improve and may even break multiple glasses at the same time.
