Blank (Media) Slate

I’ve been reading up on memory lately and found an interesting effect that might speak (in a totally non-scientific way) to something that seems to be part of our collective culture. I was listening to research CDs by Diana Deusch (see an earlier post for more background) and a pitch memory experiment caught my attention.

Here’s a quick blurb on “Short Term Memory for Pitch” from her site:

Suppose you play a tone, and this is followed by another tone which is either the same in pitch as the first, or differs by a semitone, most people find it very easy to decide whether the two tones are the same or different. This is true even when the tones are separated by a five second delay.

That’s all very well and good, of course, but when the intervening silence is filled with other tones, the task becomes much more difficult. Nothing strange there, I think we all get that. What gets more interesting, though, is when you fill the space between tones with spoken words (in this case they are spoken numbers). As Deusch says:

Most people find the memory task much easier when spoken numbers rather than tones are played during the interval between the test tones. This contrasts remarkably with the memory loss that occurs when a sequence of tones is played during the interval between the test tones, even though the extra tones can be ignored. So we conclude that the pitch of a tone is held in a specialized memory store, and that interference takes place between pitches inside this store. Other materials - such as spoken numbers - do not enter the store, so they produce much less interference with memory for pitch.

According to the background reading I’ve done in memory, it turns out that short term memory can only juggle a handful of similar items before they are either committed to longer term memory or lost. In fact, George Miller, while at Bell Labs, determined that the number of similar items is about seven, plus/minus two. Research has since shown that the number of “storable items” differs by type and situation (eg. seven for digits, six for letters, and five for words).

What I find interesting is how this might map into popular culture. For example, I’ve always wondered why people tend to remark about recent films being “the best movie ever.” I don’t take those statements literally, but assume them to be infused with exuberant hyperbole to make a point. It’s also relatively well known that in order to capitalize on this effect, movies in contention for Oscars are purposefully released near voting time.

So, if all this is well known, what’s the point of this post? First of all, I think it’s interesting to play with the temporal effect of “liking” something (ie. adding more relative weight to recent interests, degrading them over time). Second, I think it’d be interesting to explore if we’re hardwired to only allow for something like 7 +/- 2 “greatest” movies/songs/etc. in our heads at any given time.

I can’t remember how I found out about the Radio Lab show produced by WNYC, but since I’m in Boston I was pleased I could snag the podcasts from the second season (the first season being tied up in rights issues preventing their distribution as MP3s).

What really caught my ear was the “Musical Language” episode. There was a great segment on audio illusions in which they interviewed Diana Deutsch, a professor of the Psychology of Music. Specifically, they were talking to her about an audio clip she’d accidentally created of her speaking which, when heard as a loop, sounded like music. It has to be heard to be believed: WAV | MP3.

NOTE: The track begins with Deutsch speaking the full sentence, followed by a few loops of the “singing words.” Listen to the entire track, then play it again to hear the sentence again.

I was intrigued enough to pick up her two CDs (Musical Illusions and Paradoxes and Phantom Words, and Other Curiosities) to hear more. I’ve only sampled a few of the tracks so far, but they’re incredibly interesting. Especially with my interest in Beispiele paranormaler Tonbandstimmen I was keen on the “Phantom Words” tracks. What they seem to show is the incredible power of our brains to try and sift through apparent randomness in an effort to impose order (in this case turning beeps into words).

… I hear voices.

I’m in a meeting today with a conference call bridging a couple different parties, and I was struck by the power of the soundscape of various applications. Throughout the meeting (with just about everyone having laptops in front of them) there were a number of “sting” sounds heard zinging around.

After this happened a couple times (IM alerts, phone bridge tones, etc.) it felt like we were living in a cartoon… But instead of amusing “hit with a frying pan” sounds, they were all useful cues for what was going on around us. This is tangentially related to my post about sounds making a difference.

… Though everyone had their own score and it was amusing being surrounded by it all.

Sound effects came up while discussing key elements to a product we’re developing.  It’s relatively understood that sound is an important aspect to usage of various tools providing feedback to the user.  While desktop applications employ them to a degree (often relying heavily on the standard “Something Bad Happened Alert”), they’re more often treated like “ear candy”.

When used effectively, though, their effectiveness can be striking.  Take for example the soundscape generated by the TiVo.  Each sound effect carries weight and meaning reinforcing the actions users perform with the interface.  Another good example is the simple audio click of the iPod wheel giving the user the feeling of a substantial movement between selections.

It’s obvious to most users of the web, though, that it’s an oddly silent medium.  Other than the occasional (and extremely annoying) audio riffs added to some overly media heavy sites, surfing relies on the browser audio cues (eg. the link clicks in Internet Explorer).  Beyond that, however, few web sites have spent the time to develop a rich audio style guide to clue the users into action.

There are, of course, technical reasons for the silence (eg. bandwidth limitations, compatibility), but also some human factors issues, too.  It wouldn’t take long for a few well-intentioned audio metaphors to crescendo into a meaningless cacophony.  Besides, not all audioscapes would happily coexist with others.

I’m a total fan of effective audio cueing, the hurdle is defining their appropriate usage.  It is also possible, though often difficult, to further allow effective controls for the user to easily configure them without adversely impacting the overall experience for which they were intended.  Tricky stuff, but I’m convinced it’s well worth (at least) the exploratory effort.

In a related note, I’ve been a fan of auditory system health tracking for the past decade or so.  The project that sticks in mind was Peep, called a “Network Auaralizer” for monitoring networks with sound, designed by some folks at Tufts.  Unfortunately, it looks like the alpha they’d built as a proof of concept is now offline.  If you’re interested and end up noodling around for more info, drop me a line with any updated intel.