# Unamplified vocal glass shattering! **URL:** \ **Category:** Cecil's Columns/Staff Reports\ **Created:** [May 19, 2005, 7:26am UTC](https://boards.straightdope.com/t/unamplified-vocal-glass-shattering/304548 "2005-05-19T07:26:57Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [May 19, 2005, 7:26am UTC](https://boards.straightdope.com/t/unamplified-vocal-glass-shattering/304548/1 "2005-05-19T07:26:57Z")
In [this](http://www.straightdope.com/classics/a3_333.html) classic column, Our **Perfect Master** replies to an irate reader, > [@](#): > > Your beef is that I suggested this could be done with the unamplified human voice. I’ll grant I haven’t been able to turn up a documented instance of this, but it seems subsidiary to my main point, which is that you can shatter glasses with sound, and furthermore that the human voice, which can generate a relatively pure tone, is well suited to this purpose. Furthermore, none of the technical people I spoke to about this seemed to think doing it by voice alone was completely impossible. Admittedly 90-plus decibels is pretty damn loud, but one of the reasons the Memtek folks crank it up that much is that they’re using an inexpensive ($7) glass rather than fine crystal, which is more fragile. So let’s not be so negative, Timsy. It’s the can-do attitude that has made this country great. On tonight’s episode of _Mythbusters_ a leather-lunged vocalist whose name escapes me succesfully shattered a lead-crystal wine glass with his unamplified voice. He had to try 20 times and hold the glass directly in front of his mouth but he did it. Adam was able to accomplish an amplified glass shattering easily. ---
**Author:** ![C\_K\_Dexter\_Haven](https://avatars.discourse-cdn.com/v4/letter/c/b2d939/32.png) [@C\_K\_Dexter\_Haven](https://boards.straightdope.com/u/C_K_Dexter_Haven)\ **Post date:** [May 19, 2005, 5:30pm UTC](https://boards.straightdope.com/t/unamplified-vocal-glass-shattering/304548/2 "2005-05-19T17:30:08Z")
We’ve brought this to Cecil’s attention. ---
**Author:** ![oliverar](https://avatars.discourse-cdn.com/v4/letter/o/dbc845/32.png) [@oliverar](https://boards.straightdope.com/u/oliverar)\ **Post date:** [May 22, 2005, 9:10pm UTC](https://boards.straightdope.com/t/unamplified-vocal-glass-shattering/304548/3 "2005-05-22T21:10:00Z")
I recall seeing a soprano do this on British TV when I was a kid. Might have been a programme called Record Breakers. Not sure though, so not very helpful I guess… I also have the impression - as Cecil explains - that it’s a question of producing the same frequency as the natural tone of the glass, not sheer loudness alone. Also doubt many top class opera singers would wish to attempt such a novelty feat. Oliver ---
**Author:** ![Mathochist](https://avatars.discourse-cdn.com/v4/letter/m/c89c15/32.png) [@Mathochist](https://boards.straightdope.com/u/Mathochist)\ **Post date:** [May 22, 2005, 9:44pm UTC](https://boards.straightdope.com/t/unamplified-vocal-glass-shattering/304548/4 "2005-05-22T21:44:21Z")
> [@oliverar](#): > > I also have the impression - as Cecil explains - that it’s a question of producing the same frequency as the natural tone of the glass, not sheer loudness alone. That’s exactly the point about glass vs. crystal. Crystal has a much more specific resonant frequency than glass does. Try swirling a damp finger around the rim of a glass goblet and a crystal goblet and notice how easily the crystal produces a tone – the resonant frequency. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [May 23, 2005, 12:28am UTC](https://boards.straightdope.com/t/unamplified-vocal-glass-shattering/304548/5 "2005-05-23T00:28:18Z")
I’m confused, **Mathochist**. Are you saying that crystal (as in, a crystal goblet) is not glass? ---
**Author:** ![Mathochist](https://avatars.discourse-cdn.com/v4/letter/m/c89c15/32.png) [@Mathochist](https://boards.straightdope.com/u/Mathochist)\ **Post date:** [May 23, 2005, 12:40am UTC](https://boards.straightdope.com/t/unamplified-vocal-glass-shattering/304548/6 "2005-05-23T00:40:19Z")
> [@Chronos](#): > > I’m confused, **Mathochist**. Are you saying that crystal (as in, a crystal goblet) is not glass? I’m saying it’s a more specific term. All crystal stemware is made of glass, but not all glassware is crystal. As I understand it, crystal has a microscopic crystalline structure (unsurprisingly), but glass isn’t nearly so ordered. Crystal is much more susceptible to resonation than glass is, as evidenced by the experiment I mentioned. I wouldn’t expect a glass to shatter very easily any more than I would expect a bridge designed without a strong resonant frequency to shake itself to pieces like the Tacoma Narrows bridge. ---
**Author:** ![RM\_Mentock](https://avatars.discourse-cdn.com/v4/letter/r/e274bd/32.png) [@RM\_Mentock](https://boards.straightdope.com/u/RM_Mentock)\ **Post date:** [May 23, 2005, 1:04am UTC](https://boards.straightdope.com/t/unamplified-vocal-glass-shattering/304548/7 "2005-05-23T01:04:55Z")
> [@Mathochist](#): > > As I understand it, crystal has a microscopic crystalline structure (unsurprisingly), but glass isn’t nearly so ordered. I did not know that. It seems like it would have to cool a lot slower to make crystals. I wasn’t able to find any concrete info on the web. ---
**Author:** ![Mathochist](https://avatars.discourse-cdn.com/v4/letter/m/c89c15/32.png) [@Mathochist](https://boards.straightdope.com/u/Mathochist)\ **Post date:** [May 23, 2005, 1:43am UTC](https://boards.straightdope.com/t/unamplified-vocal-glass-shattering/304548/8 "2005-05-23T01:43:13Z")
> [@RM Mentock](#): > > I did not know that. It seems like it would have to cool a lot slower to make crystals. Well, even if I’m wrong about the microstructure, the experiment I mentioned shows that crystal easily hums a resonant frequency while glasses at best squeak with friction of fingertip against glass. If I had a video camera I’d demonstrate on my own Riedel tasting set and the cheapo glass stemware my parents bought for me in case I ever have dinner guests. ---
**Author:** ![mwaddell33](https://avatars.discourse-cdn.com/v4/letter/m/f05b48/32.png) [@mwaddell33](https://boards.straightdope.com/u/mwaddell33)\ **Post date:** [May 27, 2005, 5:40pm UTC](https://boards.straightdope.com/t/unamplified-vocal-glass-shattering/304548/9 "2005-05-27T17:40:39Z")
> [@friedo](#): > > In [this](http://www.straightdope.com/classics/a3_333.html) classic column, Our **Perfect Master** replies to an irate reader, > > On tonight’s episode of _Mythbusters_ a leather-lunged vocalist whose name escapes me succesfully shattered a lead-crystal wine glass with his unamplified voice. He had to try 20 times and hold the glass directly in front of his mouth but he did it. Adam was able to accomplish an amplified glass shattering easily. Yes, I saw the same episode of Mythbusters and recall them saying it was the first time this had been documented on camera. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [May 27, 2005, 7:03pm UTC](https://boards.straightdope.com/t/unamplified-vocal-glass-shattering/304548/10 "2005-05-27T19:03:58Z")
For that matter, I’ve “sung” (run my finger around the rim) quite a few glass drinking vessels, some of them very cheap. I’ve never found one of the right shape I couldn’t do it with, and I’d be surprised if all of them were crystal. ---
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [May 27, 2005, 7:20pm UTC](https://boards.straightdope.com/t/unamplified-vocal-glass-shattering/304548/11 "2005-05-27T19:20:43Z")
Yes, you can get pretty much anything other than a beer mug to sing if you rub the rim enough, but glass uh… glasses will usually produce a fairly weak “eeek” and may take a few revolutions around the rim and varying the pressure before they sound. Crystal glasses will readily sing strong clear tones with just a light stroke. Is this because they’re crystal, or because the makers of crystal stemware have better manufacturing techniques than those that make just plain glass stemware. ie: consistent thickness, symmetry, etc. The next question is - is it necessarily the material itself, or does the shape play into this? I’ve got a large brass handbell of the “come in from recess” variety (as opposed to a pitch-specific musical handbell) and while it rings in the standard manner nicely, if I rub the edge of the bell with a smooth wood dowel, it will emit an amazingly loud continuous tone. Question for _Mythbusters_: Will the echo of a duck’s quack, sufficiently amplified, be able to shatter a glass? 😃