Human echolocation, absolute pitch and Golden Ears

I’m always intrigued by stories of people with amazing abilities, and similar questions often come up. Is this for real, and is this a latent ability that we all might have?

 

A few years ago there was a lot of news stories about Daniel Kish, see “The blind man who taught himself to see”  or “Human echolocation: Using tongue-clicks to navigate the world.” Daniel is a master of echolocation, the ability to sense the environment by listening to the echoes from actively produced sounds, though Daniel is also newsworthy for his humanitarian contributions helping other visually impaired people, see his World Access for the Blind charity . His ability is amazing, and the first question, “Is this for real?” is easily answered in the affirmative. Quite a few studies have also shown that many (or most or even all) people have some echolocation ability, and that the blind generally perform better. And Daniel has taught others to hone their skills.

 

You can find Daniel Kish’s TedX talk at https://www.youtube.com/watch?v=ob-P2a6Mrjs

 

And here’s a wonderful light piece about an eight year old learning echolocation skills

This got me thinking about some other amazing auditory skills. I remember when I was a teen, at a friend’s house, and he told me the names of the white keys on a piano (my musical knowledge was nonexistent). He then asked me to play any of them and he’d tell me which one it was. I thought I’d trick him and so I played one of the black keys. He turned around surprised and said A sharp. So I tried hitting two keys, and he got that right. I soon established that he could identify correctly at most any two keys, and sometimes even three hit together. I said, “Wow, you were born with perfect pitch.” And he looked at me and said “Not born with it. It’s because I’ve been playing piano since I was four!” I also remember that he was amazing at playing music by ear, which is no doubt related, but lousy at sheet reading.

And I don’t know if he had absolute pitch in the true sense. Could he identify the note played on other instruments? Maybe his skill was just limited to what was played at home on his piano, or just generally to piano. Absolute pitch is a phenomenon where there is some debate about the extent to which we might all be able to do it. Some studies suggest that there could be a genetic trait, but there’s also a lot of evidence to suggest that it could be learned. So can anyone learn it, and can they learn it at any time? Certainly, relative pitch skills can be acquired late in life (there’s a lot of material on critical listening and ear training that help someone learn this skill), and repeated exposure can provide someone with an external reference. With enough training, enough examples of different timbres with different fundamentals, perhaps almost anyone could identify the pitch of a wide variety of different sounds.

Extraordinary auditory skills has also come up in some recent research that we’ve been involved in, see J. D. Reiss, “A Meta-Analysis of High Resolution Audio Perceptual Evaluation,” Journal of the Audio Engineering Society, v. 64 (6), June 2016, http://www.aes.org/e-lib/browse.cfm?elib=18296 .

. We were interested in whether people could perceive a difference in CD quality audio (16 bits, 44.1 kHz) and high resolution audio (loosely, anything beyond CD quality). Some anecdotes have mentioned individuals with ‘Golden Ears.’ That is, there might exist a few special people with an exceptional ability to hear this difference, even if the vast majority cannot distinguish the two formats. Our research involved a meta-analysis of all studies looking into the ability to discriminate between high resolution and standard format audio. For a lot of studies, participants were asked lots of binary questions (like ‘are these two samples the same or different?’ or ‘which of these two samples sounds closest to a high resolution reference sample?’). Thus, one could assign a p value to each participant, which corresponds to the probability of getting at least that many correct answers if the participant was just guessing. If everyone was always just guessing, then the p values should be uniformly distributed. If there is a Golden Ears phenomenon, then there should be a ‘bump’ in the low p values.

Well, here’s the histogram of p values from participants from a lot of the studies.

Picture1

You can’t really tell if there’s a Golden Ears phenomenon or not. Why? Well, first, you need a lot of data to see structure in a histogram. But also, our p values are discrete and finite. If a participant was involved in only 4 trials, there are only 5 possible p values; 0.0625 (all 4 correct), 0.3125 (at least 3 correct), 0.6875 (at least 2 correct), 0.9375 (at least one correct), and 1. So there are a lot of bins in our histogram that this participant will never hit. The histogram isn’t showing any participants who only did 4 trials, but the problem is still there even for participants who did a lot, but still finite number, of trials.

There are other issues of course. Maybe this Golden Ears phenomenon only occurs in one out of a thousand people, and those people just weren’t participants. Just one of many reasons why its hard to reject the alternative hypothesis in null hypothesis testing.

But what we did find is that, on average, participants were correct much more than 50% of the time, and that was statistically significant. More on that in an upcoming blog, and in the above mentioned paper ‘A meta-analysis of high resolution audio perceptual evaluation’ in the Journal of the Audio Engineering Society.

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