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Rest in Peas: The Unrecognized Death of Speech Recognition
Speech recognition seems good on a cell phone but accuracy for conversational speech flatlined in 2001--and no one noticed. Computer understanding of language was supposed to lead to artificial intelligence. Now we have need AI to get computers to understand language. Catch 22. We just haven't recognized it yet. (Sorry, Ray Kurzweil.)
- TravisAllison 16y agoSurprising fact despite what your smartphone tells you: speech recognition in general situations hasn't improved since 2001. A good exposition of why Norvig and Google's approach of using statistical analysis may be approaching a dead end.
- Tichy 16y agoI think something must be wrong with Norvig's approach, because humans can learn a lot faster. We don't need one billion voice samples to learn understanding. So there must be a better way than the ginormous dataset approach.
- eru 16y agoWhy? Perhaps your genes have been trained (=evolved) on big datasets to produces good speech recognizers.
- J3L2404 16y agoWell, so much for HAL reading lips - he can't even hear what I'm saying. I call bullshit - HAL's way smarter than that!
- eru 16y agoPerhaps they had better (and now forgotten) techniques back in 2001?
- MichaelGG 16y agoMSR's MindNet, mention in the article, is online: http://stratus.research.microsoft.com/mnex/Main.aspx http://stratus.research.microsoft.com/mnex/Main.aspx
- tjpick 16y agoI have conflicting anecdotes: 1. it's used heavily and successfully in medical dictation situations, ie medical professionals dictating case notes. 2. I was so excited about speech control in OSX, and I tried it, and it was shit because I had to speak with a terrible impression of an American accent to get it to do anything.
- robertfortner 16y agoI'd say they aren't really conflicting. Commercial speech recognition really started in the medical field. Accuracy is much higher with a controlled vocabulary. Speaker-specific characteristics, e.g. accent, by contrast are much harder for recognizers.
- cwinters 16y agoMedical dictation is a success for recognition, but it's important to remember that no such system can function by itself. Instead, they're often advertised as making the human transcriptionist's job easier -- reducing the number and type of fixes a human has to make when correcting the dictation results.
- mkramlich 16y agoInteresting about it being used heavily and "successfully" in the medical field. That's the one field where I'd want 100% transcription perfection. Mistakes there could kill.
- barrkel 16y agoIt could hardly be worse than doctor's handwriting...
- kowen 16y agoI paid my way through college doing medical transcription. Throughout my time there, the hospital was experimenting with speech recognition, but the success rate was very low, and the doctors spent a lot of time going over and correcting the output. I believe they finally ditched the voice recognition software (though I do not know for sure). I'm guessing that the reason the experiment failed at this hospital is that the language was non-English. In addition, most of the doctors were foreign, speaking with wildly differing accents. Also, many of the doctors would mix two languages when dictating, in addition to the usual Latin terms. Basically, it was easier to just pay some humans to parse it.
- dmfdmf 16y agoGreat article.... Like a lot of things it all hinges on P=NP.
- robertfortner 16y agoThanks for reading. But I think a key take-away is that even with infinite computing power, you only increase the chance of being right a little. It's still a guess. That's the real surprise. It's not a question of computing power.
- dmfdmf 16y agoYes, infinite computing power with current methodologies will never work. The article mentions that the number of possible sentences is of the order 10^570 and current methods attempt to crack that (or sub) solution domains (primarily) using probabilities of association. This method will never work, except on small sub-domains (e.g. numbers or medical field transcription) as the article mentioned. However, if P=NP then there are better algorithms that can solve the problem. Does P=NP? Nobody knows but to me it seems to be true because when anyone interprets speech they definitely are not searching a 10^570 domain to solve the problem.
- ahk 16y agoYour articles seem to follow a theme of "no new ideas/breakthroughs". The anecdote of the NASA head imploring people to come up with ideas was striking. Any guesses as to why this is happening now? After all, we _were_ having critical breakthroughs through much of the last century.
- robertfortner 16y agoTo some degree, I'm critiquing Ray Kurzweil who generalizes about progress. So, for better or worse, I take a lesson from that which is to be empiricist: look closely at each field to see whether it's vaulting forward or not. It's not happening in space (although hypersonics seem to be getting more real). It's not happening in AI or speech recognition/understanding. It's not happening in medicine. So the net empirical situation looks like the opposite of what Kurzweil says. Only IT and Moore's Law are going totally nuts. One can conjecture about why, but I think that's conjecture and there aren't deep fundamental principles about scientific and technological progress, at least that we've found so far.
- chime 16y agoFor those who haven't dug into the audio analysis and synthesis field, it is really hard to understand why speech recognition is so complex. As living beings, we interpret sounds in a fundamentally different way than computers. Our brain has the ability to interpret sound-waves and provide meaning and context to them without us even realizing it. Once you hear a cat's meow, even if it happens in a different frequency range later, you can still associate it as a cat's meow. This is what computers "hear": http://www.ling.ed.ac.uk/images/waveform.gif http://www.ling.ed.ac.uk/images/waveform.gif - in fact, this is ALL they can hear. When you hear 44.1khz, audio, that is 44100 bytes of information (a value between -128 to +127 per byte) per second. There is no hidden metadata behind the waveform. At 100% zoom-level, the waveform IS the audio. Theoretically, you can take a screenshot of a 100% zoomed waveform and convert that to actual sound with absolutely no loss of data (of course, you'd need a really high resolution to show a graph 44100x256 pixels in size. Now given such a waveform, how would you convert that to plain-text? As an example, try recording "ships" and "chips" into a mic and view the waveform. See if there are any patterns you can identify between the two waveforms. I've done it over a hundred times. There isn't an easy way to discern if the letter was "sh" or "ch". Yet our brain does it so very easily thousands of times every day. So, failing easy pattern recognition, we have to use frequency analysis, DFT, and tons of AI. My unscientific gut-feeling is that we're going about all of this the wrong way. We are using the wrong tools. Discrete, digital computers will never be able to tackle problems like pattern recognition in their current state. Switching to analog isn't going to improve anything either. I don't know what the correct instruments/devices will be but I know programming them will be very different.
- abstractbill 16y agoIndeed, computers are not good at listening. Even pitch detection is hard. Even monophonic pitch detection is surprisingly so (I just finished reading a bunch of papers about that).
- robertfortner 16y agoWhat word(s) are we looking at in the .gif?
- 16y ago
- kvh 16y agoI disagree. This is another example of underestimating how powerful the human brain is: it is an exquisitely designed piece of dedicated hardware with more power than even our super-compute-clusters. Hardware that's dedicated, to a large extent, to language processing. I think current statistical approaches, ramped up on future computing resources, will continue to chip away at 'word error rate'.
- xxzz 16y agoBut Hinton recently made significant advances in speech recognition using RBMs. Google Tech Talk: http://www.youtube.com/watch?v=VdIURAu1-aU http://www.youtube.com/watch?v=VdIURAu1-aU
- J3L2404 16y agoNice post. Question- Is there a relation between RBM and HMM?
- sqrt17 16y agoKind of. Both RBMs and HMMs are a mean to squeeze statistics out of something so that you can take the something away and still know what it looked like. RBMs are a bit more involved (and hence a whole lot slower, which still matters in speech recognition), while HMMs are simpler but good enough for people to stick to them (frustratingly for all the people who propose something fancier)
- mstoehr 16y agoHe didn't make any advance that has made its way to a full word recognizer, he's merely recognizing phonemes (which are linguistic subunits of words) several researchers in the field have criticized his methods. Additionally, none of the top five phoneme recognizers have ever been deployed as a word recognizer, and there is little chance that they even will be in the next few years.
- woodson 16y agoThe concept of phonemes isn't undisputed either. When analyzing actual speech it becomes clear that there are no real steady states, but much coarticulation between the "segments". Of course, part of it could be attributed to the fact that speech sounds are produced by articulatory gestures, which necessarily overlap in time. On the other hand, these coarticulation patterns are not language-independent. So, a purely (articulatory/auditory) phonetical explanation of why these differences exists is rather unlikely.. I know this seems rather off-topic with regard to speech recognition, but the question of the basic building blocks of language is kind of at the heart of the problem.
- barrkel 16y agoI think this article conflates two quite different things: speech recognition and understanding language. The problem of speech recognition, it seems clear now, is unsolvable without understanding language, because only with an understanding of language are the ambiguities inherent in speech properly resolved. But having a workable understanding of language would seem to rely on us having some kind of model of a mind. Mere statistical relations between words or sentence structures aren't enough to map human language into mental models of the world, but having a consistent internal model of the world seems to be the key to understanding language. We disambiguate by minimizing the internal inconsistency. Having a computational model for such an internal view of the world seems to be a Hard AI problem. We probably won't make much further progress with speech recognition until we've made headway there.
- cia_plant 16y agoWhere does it conflate those? I thought it discussed exactly the point you've just made.
- mstoehr 16y agoActually most research effort in speech is more on the language side rather than the signal processing of the speech signal. So I think many people have a similar intuition as yourself. Bear in mind though, that humans significantly outperform machines in tasks where isolated or streams of non-sense syllables are said: i.e. "badagaka" is said and humans can pick out the syllables whereas computers can have a lot of difficulty (in noise in particular). Computers start approaching human performance most when there is a lot of linguistic context to an utterance. So it appears that humans are doing something other than using semantics.
- fauigerzigerk 16y agoGood points, but I think we underestimate how much situational context humans use when they interpret language. Sometimes we can communicate with very little language simply because we know what the purpose of the interaction is. Another thing I keep wondering about is why so little emphasis is put on dialog. When humans don't understand something, they ask, or offer an interpretation and ask whether it's the right one. Speech recognition systems don't seem to do that. They say "Sorry, I could not understand what you said. Please repeat". That's not very helpful for the computer of course. It should say: "Huh, Peas? Why would anyone rest in peas for heaven's sake??". Then the human could sharpen his SS and say "PeaCCCEE!!! not peas. I'm not talking about food, I'm talking about dying!".
- nostrademons 16y agoThis comment is voice posted to my nexus 1, without ed its. I find that the speech recognition on my next 1 is adequate 4 basic search queries. I tried old freezes listed in the article as search query. Rest in peace high st correctly. Sb inspiration came out of sudan inspiration. Serve as the installation, remarkably, king out exactly correct. Saving 1 into the phone give me a number instead of a word. Saying recognize speech came out okay. The problem with speech recognition of long passages things to beat that there is a large amount of information beyond the worst insults. This looks like that speak for example. Humans are also very sensitive to misplaced woods. That would be in the last sentence completely changes the meaning of this. I also found the speaking twin machine feels very natural. I have to stop and pause between each sentence because i can't remember what i'm thinking about. As you can see from descon and, speech recognition has a long way to go to it. But you can at least sort of get the gist of the conversation.
- nostrademons 16y agoI'm going to forget what I actually meant to say above by morning, so here's the translation typed out: "This comment is voice-posted from my Nexus One, without edits. "I find that the speech recognition on my Nexus One is adequate for basic search queries. I tried all the phrases listed in the article as search queries. 'Rest in peace' parsed correctly. 'Serve as the inspiration' came out as 'Sudan inspiration'. 'Serve as the installation', remarkable, came out exactly correct. Saying 'one' into the phone gave me a number instead of a word. Saying 'recognize speech' came out okay. "The problem with speech recognition of long passages seems to be that there is a large amount of information beyond the words themselves. This looks like netspeak, for example. Humans are also very sensitive to misplaced words. The 'woods' in the last sentence completely changes the meaning of it. I also found that speaking to a machine feels very unnatural. I have to stop and pause between each sentence because I can't remember what I'm thinking about. "As you can see from this comment, speech recognition has a long way to go before it becomes practical. But you can at least sort of get the gist of the conversation.
- dirtyaura 16y agoThe article highlighted that that recognition accuracy has plateaued around 80% and this hasn't really improved much in 00s. Glancing over your trial, it seems that Nexus One is below 80% recognition accuracy. Thus, if the claim of the article is to be believed, speech recognition might never become practical.
- noisedom 16y agoIs the problem in guessing phonemes or guessing which word is being said based on the phonemes? I'd assume that phonemes are easy to guess at since it's such a small set compared to the number of possible words.
- donaldc 16y agoIt's not dead. It is in fact used a lot more than ten years ago. I've yet to get a voice message that google voice was not able to decode sufficiently, and most of the transcribed messages have been 100% accurate. General speech recognition has a long way to go, but it will happen last in speech recognition. Meanwhile, in the real world, speech recognition is noticeably better for everyday use than it was a decade ago.
- ebiester 16y agoTwo anecdotes: First, I worked with a quadriplegic engineer who relied on speech recognition. While it wasn't perfect, he certainly did well with it. The trick is that he trained himself as much as he did the computer. He spoke more slowly, and enunciated the places where he knew of problem points. I don't even know how much of this was conscious - I only watched a few times and never asked him. If we treat our voice recognition similarly, we get much better results. 2. Due to a few too many loud concerts and bars, I have partial hearing loss and can miss words myself. The difference between myself and a computer is that the computer is expected to output immediately rather than being allowed to wait for more context clues, and the computer isn't allowed to interrupt to ask about words. These two strategies, allowing for a more conversational flow, may be what we need to improve speech recognition.
- ephermata 16y agoWhile the article focuses on speech recognition for arbitrary speech, it misses the fact that speech interfaces for specific situations are now actually useful. Today, I told my car "play track 'severed head'," and it actually played the correct song. I asked my phone "what is my next appointment?" and heard my calendar. I then said "dial 206 421 8989," my phone dialed properly, and so on and so forth. This is all without any explicit training on my part. No need to read Mark Twain or anything like that. There are still problems here, but the technology for speech interfaces has gone from terrible to OK in the last seven years. I'm looking forward to seeing where it goes next.
- jerf 16y ago"But sticking to a few topics, like numbers, helped. Saying “one” into the phone works about as well as pressing a button, approaching 100% accuracy. But loosen the vocabulary constraint and recognition begins to drift, turning to vertigo in the wide-open vastness of linguistic space." "As with speech recognition, parsing works best inside snug linguistic boxes, like medical terminology, but weakens when you take down the fences holding back the untamed wilds." No, it did not miss it. It was a core point of its argument; the entire arc of the article is about how we made steady progress on the small cases but crapped out on the general case.
- billswift 16y agoI think the core difficulty to further speech recognition is semantic understanding. One of the reasons computers aren't good at it yet is sheer lack of computer power. Which forces them to use less context to decide word meanings. There is a reason humans think and remember things mostly in the form of stories, it provides more context for memory and decoding cues. The article talks about how much computer power has increased over the last decade without any increase in transcription accuracy ("freakish" is the word it uses) without mentioning the fact that it is still enormously behind human processing capabilities.
- Tichy 16y agoA total horseshit article... I mean to conclude from a lack of progress for a couple of years that AI is impossible.
- Tichy 16y agoThat was quote from the article btw.
- motters 16y agoSo the question remains as to how to get that last 10-15% of transcription accuracy. It sounds as if existing methodology has run out of steam and that a paradigm shift is required to get to human-like speech recognition.
- wglb 16y agoMy favorite hard-to-understand phrase is "Isle of Lucy", which is pretty tough to get right when spoken human-to-human.
- discipline 16y agoTotally anecdotal, but I thought I'd pass this on. Whenever I use Goog 411 or Dragon, my results improve if I speak like a standard radio announcer. You know, that kind of jokey, fake lilting voice that they use on car commercials? I hate doing it because I sound like such an ass, but whenever I've done so, Google understands what I'm saying. YMMV.
- RyanMcGreal 16y agoWas speech recognition software ever any good for anything other than having fun with your kids?
- jheriko 16y agoI wouldn't draw so much from what looks like a local minimum - especially when the abilities of people imply that there is a suitable algorithm. The problem is its no longer a successful marketing gimmick - it won't help to sell software/hardware anymore until it works as well as people do.
- korch 16y ago"It's hard to wreck a nice beach"
- JasonAllison 16y agoSpeech recognition is pattern recognition. Computers are inefficient and relatively limited in their capacity to discern relevant data from complex data sets when the size of these sets begins to soar exponentially. That's why weather prediction in many areas isn't worth much more than a week. Consider how well the human brain can synthesize disparate data in the relatively simple form of sentences with scrambled word spellings. Add to this, the nearly infinite combinations of vocabulary, grammar, voice tone and context of speech and we can begin to see the scale of the task of matching with programs and algorithms, what the human mind does unconsciously in real time with a high degree of accuracy. http://simplebits.com/notebook/2004/01/16/mipellssed-wdors/ http://simplebits.com/notebook/2004/01/16/mipellssed-wdors/ Mipellssed Wdors Posted on January 16th, 2004 at 1:44 pm Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn’t mttaer in waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht the frist and lsat ltteer be at the rghit pclae. The rset can be a total mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. Amzanig huh? Filed in: misc