But being an audio guy (20 years in radio) I appreciate the value of audio communication. And I want to make one thing crystal clear: AUDIO ROCKS!!!
Who doesn't like audio? What am I, nuts?!!! Of course audio can be very effective.
My position is simply that audio is not always required, or even desirable. Billboards neither utilize nor need audio to be effective.
At the same time, in place-based DOOH messaging, many times there is already ambient audio playing. You can hardly go anywhere retail-oriented without being blasted with someone else's idea of a "good" soundtrack or radio channel. This is not only annoying, it is extremely distracting for many people, me being one.
Audio clutter can be every bit as destructive to effective messaging as visual clutter. I have always been a proponent of focused, directed messaging, without clutter.
That being said, there are definitely times when audio is not only helpful, it's critical. When you really want to grab someone's attention, use audio unexpectedly, and with a clear focused point and benefit. For example: Let's say you have a digital sign hanging in a salon window with an attractive woman modeling a hair style. If the model were to all of a sudden, look you straight in the eye, and address you, digital though she may be, it would get your attention, big time. If she then proceeded to call your attention to the fact that if you bring your wife in for a cut, you can get one for free, you'd probably strongly consider the offer!
That entire chain of events began with the disruptive and unexpected use of audio. A definite advantage. Like all strategies, when overused, it reaches a point of diminishing returns. But in small, selective, strategic doses, I like audio for DOOH. What do you think?