Did your audience still hear your voice after your presentation?

In her Knockout Presentations Blog on August 8th a post by Diane DiResta titled Can Your Audience Still Hear Your Voice After Your Presentation? posed that provocative question that was asked at the National Speakers Association (NSA) convention.

It was meant figuratively, but it also has a literal answer - just for a second. For music two seconds also is fine. Look up the Wikipedia entry for Wallace Clement Sabine, who found that the aptly named Fogg Lecture Hall at Harvard had an unacceptable reverberation time of five and a half seconds. I’ve posted about room acoustics before. 

Figuratively speaking, it is all too easy to put your audience to sleep with an uninspired presentation. Staying creative, and writing speeches that tell stories isn’t easy.

Pages 14 to 18 of the July/August issue of the NSA’s Speaker magazine had an interview with screenwriting lecturer Robert McKee about The Business of Story.

Also, On August 5th the Convene blog had a post about 5 Ways to Keep Your Best Ideas Flowing.

There was an excellent four page magazine article about how to Reclaim Your Creative Confidence by Tom and David Kelley that appeared in the December 2012 issue of the Harvard Business Review on pages 115 to 118. You can download a reprint here or here. They discuss overcoming four fears of: the messy unknown, being judged, the first step, and losing control.

Images of David E. Lillienthal and Senators Maloney and Radcliffe both came from the Library of Congress.  

Know the room before you get up to speak

Before you begin a public speaking engagement you should get to know the room. Every room is unique. What you don’t know may surprise you later. Also don’t forget to check other features of the building, like locations of restrooms and water fountains.

The Capitol Club Toastmasters meet just after noon on Wednesdays. We use the Cedars Conference Room at the Boise Housing and Community Development building The U-shaped seating layout for our meetings is shown above. With two people per table we can fit an audience of 16 club members. When we have more than that, we can easily add rows of tables at the back, as I have shown above for 24 people.

This room is L-shaped, about 28 feet wide by 50 feet deep. It is small enough and live enough that we don’t need a public address system. Double entry doors at the front are near the front entrance for the building. The left wall has windows with vertical blinds for light control. Near the back of the left wall is an exit door, which we usually ignore.

There are whiteboards along the front wall. The ceiling has chandeliers and recessed spotlights. The right wall has an 8-foot table for literature, food, or drinks. A supply of 1.5-foot by 6- foot tables and stacking chairs are stored along the back wall, so the seating arrangements can easily be changed to fit different groups for meetings or classes. There sometimes is an easel for flip charts stored along the back wall.

A table at the front holds our lectern, and has room for a laptop computer and projector for PowerPoint presentations. We use the whiteboards on the front wall instead of a flip chart, and also as a projection screen.

With the chandeliers off we can display PowerPoint, when the slides have dark letters on a light background. Those whiteboards are not reflective enough to provide good contrast for light letters on a dark background.

Once the front entrance to the building was blocked for repainting. That day we got in via the side exit door. During our meeting so did four confused visitors looking for the way to the front desk. Fortunately the Toastmaster that day worked at a credit union and had excellent customer relations skills. Maxine calmly greeted each of them, and then directed them out the entrance doors.

A kitchen is adjacent to the back of the conference room. It is used by Life’s Kitchen, a food-service training program for at-risk young adults. They run a Cafe that serves lunch in another room in the building. Their young employees almost never interrupt our meetings with outbursts like on the TV show Hell’s Kitchen.

For PowerPoint I bring a file box containing my laptop computer and projector, with the connecting cable, and a remote control. I also bring an extension cord to plug into the outlet at the center of the front wall and run to to the front of the table next to the lectern. A three-way adapter plugs into the extension cord. A small 2x4” wood block raises the front of the projector so the top of the image is near the top of the whiteboard and visible to the entire audience. The speakers on my laptop computer are not loud enough to fill the room. When I need audio, I also bring along a boombox radio with an auxiliary input jack, and a connecting cable to the headphone output on the laptop.

Room acoustics and background noise

There is an excellent web page that illustrates both with sight (waveforms) and sound clips how increasing the reverberation time (0, 0.8, 1.3, and 2.0 seconds) makes speech less intelligible. Another page on the same site has two more sound clips of the same speech sample with both a shorter reverberation time of 0.6 seconds and a longer one of 5.0 seconds.

Background noise is another factor that affects how clearly a speaker is heard. A room might sound fine until the heating or air conditioning system starts running. To avoid an unpleasant surprise, a speaker should plan ahead to watch and listen to the room for long enough to find out what the ventilation does.

Effects of reverberation time (RT) and background noise are discussed at length in an publication by the Acoustical Society of America about Classroom Acoustics. There also is an American National Standard for Acoustic Performance Criteria, Design Requirements, and Guidelines for Schools, which is summarized here. Jonathan Sheaffer has discussed the Prediction and Evaluation of RT Design Criteria. He plots suggested times both from an acoustics handbook and two European standards.

The sound just goes round and round

One important constraint for a speaker is room acoustics - how sound behaves in the space where you speak. Some spaces are excellent, like Symphony Hall in Boston. Other spaces, like sports arenas or stadiums, are notoriously poor - about like speaking in a fishbowl. Most of us are more likely to speak in a local church or high school gym, but we still need to consider the space when planning a speech.

Reverberation time is an important factor which describes how sound behaves. It measures how long it takes for a sound to die away completely, and depends both on the room volume and how sound is absorbed. Speech is more intelligible when the reverberation time is short, somewhere around a second. Music sounds better when the reverberation time is around two seconds. Before it was fixed the San Diego Sports Arena had a reverberation time of around seven seconds.

Sound travels much more slowly than light. The speed of sound is about 1125 feet per second. You can estimate how far away a lightning strike is by listening for the thunder, and counting five seconds per mile. A concert hall is much smaller than 2250 feet, so the two second reverberation time represents many reflections of sound from different surfaces. The sound bounces round and round before it dies away.

For two years Marisa Minor was a keynote speaker in the Miss Ohio program, and learned to deal with crowds of several thousand people. Some of her advice for large audiences is that:

“The actual words of the speech must be altered to suit a larger audience, as well. Short sentences are better for larger crowds. Longer pauses are more effective. The use of powerful verbs and strong statements is amplified in the presence of several thousand people. They can sense each other’s excitement, which triggers the memory to recall that feeling long after the speech is over. The manner of speech is also important in delivering to large audiences. Projecting the voice, enunciating up to 5x more than you would in normal speech (which will come across as “normal” to the audience after reverberation has taken its toll), and using more exaggerated inflection (the rising and falling of pitch) all lend to a professional-sounding speech.”

Speaking in stadiums, arenas, or large auditoriums

On June 2nd Steve Siebold video blogged about the ways in which speaking to very large audiences differs from the smaller ones most speakers are familiar with. His video showed the exterior of the famous Madison Square Garden in New York City. The Garden holds an audience of up to up to 20,000 people. An earlier podcast in March 2009 described speaking to an audience of 8000 in Los Angeles. Mr. Siebold identified three differences between stadiums and smaller spaces.

The first difference is that it takes much longer for a very large crowd to respond. Their reaction runs through the audience like The Wave at a football stadium. A speaker will need to wait for it. Before he even can start he may have to wait a few minutes for the crowd to settle down.

The second difference is visual. There are gigantic video screens (JumboTron or Imag) beside the speaker. Also, the stage lights may be so bright and hot that the speaker will find it difficult to see most of the audience.

The third difference is audible. It takes far longer for a voice to echo and die away, so he will need to speak more slowly in order to be heard clearly above the background from reverberation. A speaker needs to check and listen to someone else before speaking. I will discuss reverberation in another post.

The current Madison Square Garden is the fourth building to bear that name. It is such a well known name that its lack of reality is overlooked. It is not a square, not located at Madison Square, and definitely not a garden. Madison Square Garden has hosted concerts, speeches, and political conventions, but mostly is a sports arena for hockey and basketball.

A sports stadium or an arena is not a concert hall or theater. It is not the best possible space for public speaking, as Jonathan Sprinkles discusses in this video.

The image showing a hockey jersey retirement ceremony is from Iris Kawling.