sarahcompressedUnless you’re a DJ, or have one of those high-end digital music players, mixers, or mixing software tools (and actually read the instruction book) you probably don’t know what Pitch Lock is. Basically, it’s a function that allows you to change the tempo (speed) of a recording without changing its pitch. DJ’s use this function to ‘sync’ two songs so that one blends into the next. This is called ‘beatmixing’ and here, from the DJ Cafe site, is an example of how it’s used, with cross-fading (lowering the volume of the ending song while increasing the volume of the starting one) to make a series of songs with different beat-per-minute tempos into one ‘endless’ song:

If the song the crowd is hearing is 130 BPM, and the next song you want to play is 132 — you slow the second song down to 130 bpm using pitch control, and cue it up to the beat. When you are ready to bring the second song into play, throw the record so the beats stay aligned and listen to it on your headphones. Make sure they are in sync!! Once you are sure things are in order, use your cross fader to let the new song blend into the old one, and eventually go completely across so only the new song is playing. This will give the illusion that the song never ended.

I didn’t think much about this, although one of the software tools that works with my MP3 jukebox has a Pitch Lock feature, and it was kind of fun slowing down and speeding up my favourite songs and second-guessing whether the artists should have picked a different tempo. But then this afternoon I was listening to one of my favourite songs from the new Sarah McLachlan album on the radio and it sounded funny — a lot faster than the version I was used to. I figured it was a remix so I listened through and the DJ announced it but didn’t say anything special about it. So I cued up the original and listened, and I knew it wasn’t a remix or my imagination. And then it occurred to me: The station is using Pitch Lock to speed up the songs by a just-less-than-noticeable amount so they can play more songs per hour and have more time for commercials.

So that got me thinking: What else could this be used for? Consider this fact: Average speech is about 140-160 WPM, and when we try to speak much faster than that our speech becomes slurred. When we’re thinking about what we’re saying, we talk even slower — 80-120 WPM. But we are able to comprehend properly-articulated speech of 210 and even 240 WPM without difficulty (average reading speed, by contrast, is 275 WPM, and speed readers top 800 WPM, though they don’t read every word). So that means that we could use Pitch Lock to accelerate speech by 50%, to a speed much faster than we could crisply deliver it, but with no loss in comprehension. And thanks to Pitch Lock, it would come out in the same deep, calm, enticing voice as the original, but deliver 50% more words, information or argument per minute. Still think this is a silly innovation?

Here are some commercial and time-saving applications that occurred to me right off the top of my head. I’m sure there are more:

  1. Voice-mail message replay: Double the playback speed to whisk past the ums and ers and retrieve your messages in half the time.
  2. Audio tape/audio book learning: Get through the tapes in 2/3 the time; learn 50% faster. Ditto for audiotaped or even videotaped conferences.
  3. Advertising: Tell your customers, or your potential voters, 50% more in the minute you’re paying for. And maybe, by using up their idle brain time, reduce attention deficit syndrome and get people to pay closer attention to what you’re saying to boot. Or maybe not.
  4. Language learning: Slow down the playback speed while you’re learning a language, and gradually increase it as you learn to parse the words faster and as your vocabularly grows. This could also be used for simultaneous translation in conferences, as long as they allowed short breaks after each speech for the translator to catch up.
  5. Padding a good show: If the show you’re watching or the music or talk you’re listening to is wonderful, and you never want it to end, or if you’re a producer and the program’s a bit short, just use Pitch Lock to stretch it out a bit. After all, if Bernstein can get away with stretching Samuel Barber’s famous and extraordinary 6:50 Adagio for Strings into a piece that lasts over 10 minutes without adding any notes, maybe he’s on to something.
  6. Studying and transcribing music: Having trouble following the chord changes or finger patterns in a favourite song? Slow it down with Pitch Lock and take your time. Likewise if you’re visually disadvantaged, slow down speeches to the pace at which you can comfortably take notes.

These and other applications could be exploited either at the time of recording, or at the time of playback. I’m sure the military and forensic sciences are already using this. It might also be used to listen to heart-beats, or study the songs of whales or birds, in slow motion yet at an audible pitch level. Or to determine an optimal speaking rate for computerized voice synthesizers (likely a lot faster than today’s unsophisticated versions).

What else could Pitch Lock be used for? And what if we combined it with other new technologies: For example, could we teach speech-recognizing computers to ‘speed talk’ much the way we ‘speed read’, to ‘read aloud’ or play back the common words that make up 80% of normal speech and are not essential to understanding at, say, 500 WPM, and the rest at 200 WPM, so we could become 400 WPM ‘speed listeners’ and ‘speed learners’? And in this increasingly oral/aural culture, might we then give up reading and writing entirely?

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  1. Marty says:

    VMX (voice mail vendor) has had rapid playback for 10 years or so…

  2. Mike says:

    This was incorporated into some streaming audio software similar to RealPlayer. I recall years ago listening to this guy who had an audio column. It was interesting stuff (about computers, god help me I can’t recall the guy’s name or the title of his show). Anyway, he spoke in a reeeeaaaallllly sloooowww drawl. It was painful to listen to yet with this software I could speed it up to normal conversational speed w/o changing the pitch. So, in short, it’s been done.

  3. Winamp has it, when you use the appropriate plugins. Add text-to-speech plugin, and there are many possibilities. All for free, or low cost.However, I don’t like the whole idea whan taken to the extreme.It’s like eating: just to get your calories, you could just as well spend less than five minutes a day.But that’s no fun. No culture.If you want to save time: save it in order to use it to do what else instead?

  4. Life Tenant says:

    Very interesting post. I’m impressed yet again at how many interesting ideas you have about a variety of topics, and how often you capture those ideas in articulate & engaging fashion on your blog.

  5. Dave Pollard says:

    Thanks, everyone. I wonder why, when it’s been ‘out’ for awhile now, no one seems to have picked up on the non-DJ-related applications of this technology, that could have profound social implications. Maybe it will be like Fax technology, invented and used by the army in WW1 but whose commercial and social value wasn’t realized for another 60 years.

  6. Vincent says:

    Thanks to you I’m now converting my audio book library into higher-speed mp3s. I can manage to squeeze a ten hour book into less than five hours now, and it makes them easier to follow because my attention span doesn’t have time to break. Thanks Dave.

  7. gordsellar says:

    I think there might be some point atwhich accelerated speech might be a stressor, though. Some use of the tech would probably be okay, but faster isn’t always better. Puts me in mind of reading Kant or Nietzsche, and how readers need to read more slowly and carefully. I would be suspicious of any scheme that expects accelerated learning, as a result of accelerated exposure, because the key to learning is retention. Maybe we can retain more quickly than we’re accustomed to for short periods of time, but I think most people hit a limit as far as speed of rentainable exposure to information… and beyond it their retention probably approaches zero. (Like the old story about reading books so quickly yuou hardly remember what they were about several weeks later.)I could be wrong. But considering that our speech-comprehension is an evolved thing, and that speech is naturally at a certain average pace, it’s unlikely we’ll transition for faster speech fully comfortably. Though, on the other hand, I did know a blind guy whose screen reader was set at an incredibly high speed. He worked on his PC all day long and seemed fine after a day of debugging software. So maybe we can get accustomed to it. I don’t know…

  8. baaa says:

    Pitch lock is the function of changing speed WITHOUT affecting pitch.It is NOT simply adjusting speed of playback to match BPM. This latter is what most DJs do. In fact, most DJs who know their art do not use “pitch lock” features because it introduces digital artifacts into the song.Do yer homework :)

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