Then in 2005 the Discovery Channel television show MythBusters tackled the question, recruiting rock singer and vocal coach Jamie Vendera to hit some crystal ware with his best shot. He tried 12 wine glasses before stumbling on the lucky one that splintered at the blast of his mighty pipes. For the first time, proof that an unassisted voice can indeed shatter glass was captured on video.

Vendera's glass-breaking wail registered at 105 decibels—almost as loud as a jackhammer. Not many people can muster the lung power for that kind of noise. Opera singers train for years to build up the strength to produce sustained notes at volumes above 100 decibels. (By comparison, typical speech is around 50 decibels.) Although I was trained as an opera singer before becoming a science journalist, I have never personally witnessed the phenomenon or been able to recreate it myself. That's not to say I won't try again—but perhaps I should procure a horned helmet, gilded breastplate and, most importantly, good amplifying speakers first.

4 Comments

1. 1. tomlee59 08:55 PM 10/14/08

   Minor nit: Memorex does not make speakers. The Ella Fitzgerald advert showed her breaking a glass while singing live, and then breaking another glass when a recording of her voice on Memorex *tape* is played back. This was the famous "Is it live, or is it Memorex?" ad. So, assuming that no trickery was used in the first part of the ad, then the Mythbusters episode does not constitute the first time such a breakage was filmed.

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2. 2. bobpritchard 10:07 PM 4/23/11

   Back around 1978 I was a member of the UBC University Singers, an elite choir many of whom went on to have successful careers in choral and opera performance. For one of our rehearsals our conductor, Prof. James Fankhauser, placed curved reflectors behind us to help refine tuning. About midway through the rehearsal we crescendoed to a cadential chord on which we had been doing some very precise tuning work. At the exact moment that Prof. Fankhauser cut us off there was a loud "ping" from the ceiling and a jagged 2" thick section of one of the heavy glass lenses covering the hall lights dropped, shattering on the edge of the reflectors.
   
   I was always intrigued by this: if we hadn't had the reflectors in place one of our basses would have suffered a severe head injury, given the size of the lens fragment. However, if we hadn't had the reflectors in place we probably wouldn't have had the tuning, resonance and amplitude to cause the fracture (if, indeed, it was caused by our voices). The distance from the stage to the ceiling is around fifty feet, but one of the singers was Ben Heppner, who went on to top international status as an opera singer, and this was a full choir, not a solo voice, so there was a lot of sound coming off the stage. As well, Professor Fankhauser often insisted on using just intonation in tuning chords, which could contribute to reinforcing a resonant frequency.
   
   While I'm aware that the heating of the lens and manufacturing defects will likely have contributed to the event, I have been associated with UBC Music since the 1970's and have never heard of a similar occurrence for any of the 50 odd lights in the Recital Hall.
   
   Prof. Bob Pritchard

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3. 3. Operadical 04:26 PM 5/23/11

   Can the high C of a trained soprano quiver glass into dissolution? I don't know about the high C, but the high Ebs in the new song OpeRADical sung by Markella Hatziano probably could.

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4. 4. JAllan 04:29 PM 2/21/13

   The Memorex ad showed Ms. Fitzgerald breaking the glass live WITH amplification, and the recording (presumably at the same volume setting) breaking the glass also.
   
   The Mythbusters replayed that classic ad on their show, and noted that amplification was used; the microphone in front of the singer and the speaker in front of the glass were both visible. As they said on the show, they believed they were the first to do so with the glass directly in front of the singer's mouth WITHOUT amplification.
   
   It's just too bad, in my personal opinion, that they used a punk rock singer instead of an opera singer; maybe Pavarotti refused or wanted a fee beyond their budget.

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