More and more presenters want to add audio and video segments to their presentation slides to increase the impact that their message has – and even if you aren’t wondering how to do this, you probably want to know if it is worth it. Any item on a presentation slide should be there for one purpose only – to increase the impact of the message being delivered. Once you have decided that an audio or video segment will add to your message (and you aren’t adding it just because you like it), here are some ideas to consider.
Preparing Quality Audio Segments
If people can’t understand what is being said on an audio segment, then there is no point in using it. The quality of an audio segment is magnified – for better or for worse – when it is amplified through a sound system. A good quality audio segment sounds clear and crisp, and a poor quality audio segment sounds even worse and more distorted when it is amplified. One of the biggest factors that determines the quality of the audio segment is the sample rate of the recording. The sample rate refers to the number of times that the audio signal is sampled as it is recorded into digital form. The higher the sampling rate, the better the quality of the sound. CD quality sound has a sampling rate of 44,100 while the telephone uses a sample rate of 8000 (measured in Hertz). You want to get as high a sample rate as possible on the original recording because increasing sample rate through conversion is very difficult to do. Another factor in quality is whether the recording is in stereo (both channels recorded) or mono (only one channel recorded). A stereo recording has better sound because it is closer to sounds in the real world where we hear in both ears. A higher quality sound recording will create a larger file on your recording device and a larger audio file on your computer, so this may be a trade-off you need to keep in mind if you are distributing the file on a format such as diskette or CD. If you are recording the audio segment yourself, keep these factors in mind when selecting the sound quality and consult an audio recording professional if you need further assistance.
Audio File formats
Once you have the audio file recorded, you need to store it. If you are going to store it on your computer, you need to choose which audio format to use. The most popular file formats are WAV (a file format created by Microsoft) and MP3 (a compressed format used mostly on computers). Each file format has its reported advantages, but each seems to satisfy most users needs if the quality of the recording is sufficiently high. You can also choose to store your audio file on tape or CD format, in which case you will probably play the audio from a piece of equipment other than your computer. Today, the best choice is to store your audio in a digital format so that the quality is maintained over time, the older analog format (used on regular audio tapes) deteriorates as it is played over time.
Playing Audio in the Presentation
Once you have chosen the file format, you will need to play the file during the presentation. The most direct way is to incorporate the file into the presentation file and have the presentation software play the file either automatically or at a specified time. To insert the file into the presentation software package, it must be compatible with the formats supported by your software. If your file is not compatible, or you don’t want to insert it into your presentation file, you will use a sound system to play your file from usually a tape or CD format. This requires coordination of the presentation equipment and the sound system, but the audio equipment to play a tape or CD is available almost everywhere. Either way you choose to play the audio, test the quality at a volume level that will be used for the actual presentation. What sounds fine through headphones may sound very different when amplified to fill a large room.
Preparing Quality Video Segments
The quality of the video file is primarily dependant on the resolution that you use to record the video. Changing resolutions on video files is more difficult than changing sample rates in audio files, so you want to record at the resolution that you need for your presentation. Most video will be recorded in a digital format and copied to your computer from the video camera or recording device. You can use simple tools to edit your video if you need to.
Video File Formats
Digitized video can be stored in a number of different formats, the most popular being QuickTime (from Apple computer), Windows Media Video Format (WMV files from Microsoft), AVI (Audio Video Interleaved format) and MPEG (Moving Picture Experts Group compressed format). The quality and size of the video file will be determined by the resolution you select when converting the video to a digital format. The higher the resolution, the better the quality of the video and the larger the file size. You will want to select the resolution based on the ability to show a large enough picture on the screen that people can clearly see it from the back of the room.
Playing Video in the Presentation
Insert the video file into your presentation file and have it automatically play or play when you specify. Make sure that the size of the video is large enough so people at the back of the room can clearly see the video – test this so you know for sure. You will need to send the audio part of the video segment to the sound system so that people can hear the audio part as well as see the video part. As with an audio segment, test the volume of the audio part of the video segment to make sure everyone will be able to hear it clearly.
Obtaining Permission to Use Audio or Video Segments
If you or your organization did not create or do not own the audio or video segment, you must have permission to use the segment from whoever does own it. For audio segments, you will likely have to contact the person who is speaking, the publisher of the product or for music, an association that has permission to grant rights to the work. For video segments, you will likely have to contact the producers of the video to discuss fees for usage. In many cases, you need to state how you will use the segment and depending on the type of use and number of times you plan to use it, the fees will vary. If you do not obtain permission, you run the risk of legal action that will ruin your reputation. It is important to be clear about your obligations when licensing audio or video segments and it is usually a good idea to obtain legal advice on this subject.
Audio and video segments can add impact to your presentation if they are high quality segments and used properly.
You can learn more about incorporating video in your PowerPoint presentation on my webinar here