As I’ve mentioned over the course of my ongoing series A history of the radar sense, Daredevil’s ability to detect and identify objects and obstacles has been described in several different ways. One interpretation is that is actually works like a real radar in that Daredevil’s brain sends out an electromagnetic signal which bounces off surrounding objects and returns to his brain. A variation on this theme (see panels below, from Daredevil #167 by David Michelinie and Frank Miller) is the active sonar which instead suggests that the signal sent out is ultra-sound. The principle is still the same though.

Daredevil's radar as sonar, from Daredevil #167

Other interpretations over the years have been 1) the radar as a combination of Daredevil’s other senses, 2) the radar as some unknown mystical sixth sense and 3) the radar as an ability to sense differences in air pressure. The way I see it, item number one on this little list would actually be (passive) echolocation since no other sense aside from hearing would actually yield the kind of spatial information that could fill in for sight. This interpretation is close to what Bendis suggested while he was writing Daredevil and also comes pretty close – in theory anyway – to the radar sense in the Daredevil movie.

While the interpretation of the nature of the radar sense has varied quite a bit, the things that throw Daredevil off his game have not. Time and time again, we’ve seen Matt complain about excessive noise and general turmoil interfering with his ability to make sense of his surroundings. This could mean that it simply makes it harder for him to concentrate – assuming that concentration is required – or that it physically interferes with whatever signal that he depends on, whether it’s a sound he sends out himself or something he picks up from the environment.

I’ve gradually come to favor the theory that Daredevil’s radar sense is sound-based and that it should rely on the same ability that many real life blind people have, though the ability would be greatly improved due to Daredevil’s heightened sense of hearing. This would not only explain why he avoids noise and massive crowds, the fact that no additional abilities are required is appealing for other reasons as well.

If Matt can emit high-frequency sounds, where would these come from? Sounds don’t just appear out of thin air. Does he have a clicker in his brain? For that matter, where would a radio signal come from? Where would the extra energy come from to fuel such an emitter? Of course, the Marvel Universe is full of characters who rely of massive amounts of energy that they are just magically able to tap into, but for Daredevil – an admittedly low-powered character – a more down to Earth solution is simply more elegant.

But if the radar sense is actually a skill based on echolocation, wouldn’t Matt know exactly what it is? Would he still have described his abilities to Ben Urich with the words:

“But most important is a sort of ‘radar-sense’. I can’t explain it — but it guides me unerringly through a world of darkness, Ben.”

Daredevil #164

Wouldn’t he know that his perception of objects, his ability to “sense” them, was based on hearing? If he’s anything like many of the blind people throughout history who have excelled at moving through complex environments unaided, the answer is probably “no.” The brain is so great at playing little tricks on its owner that an ability that is hearing-based may not feel like hearing at all. To explain this, let’s take a trip back in time…

“Facial vision”

Anecdotal reports of blind people showing an unusual awareness of their surroundings go far back. However, the term facial vision – still used occasionally to describe an ability we now know to be based on the perception of echoes – harks back to “only” a little over 250 years ago. In 1749, the French philosopher Denis Diderot wrote of a blind acquaintance:

“(He) judges of his nearness to the fire by the heat, and of a vessel being full by the noise made when pouring liquid; and he judges of his nearness to objects by the action of the air on his face. He is so sensitive to the least changes in the currents of air that he can distinguish between a street and a closed alley.”

The idea that the sense of pressure on the face many blind people experienced was due to air pressure stuck around for quite a while and the phenomenon of human echolocation wouldn’t be carefully examined until the mid-1940′s (echolocation in bats had been described in 1938 by a Donald Griffin who also coined the term). In experiments over the next decade, it was shown that hearing was both required and sufficient to account for the phenomenon. That doesn’t completely exclude other factors, but we know for a fact that the ability to echolocate diminshes with decreased hearing and is completely absent in the deaf.

How does human echolocation work?

Hearing and vision are known as our distal senses in that they give us direct information about things and events located or occurring at a distance from us. Sound gives us information in two different ways. There’s sound that comes directly from the source of objects that generate their own sound. This sound can also interact with otherwise silent objects and be absorbed or reflected. The quality of the reflected sound differs from the original sound in that the pitch and intensity will be different. This difference can be discerned by the human ear. One very simple test you can do yourself right now is to close your eyes (not necessary, but it helps), make a consistent “shh” sound and pass you open hand, fingers together, in front of your face with your palm facing in and hear how the sound changes.

These sound changes are subtle to the untrained ear but the fact is that we listen quite a bit to echoes without thinking about it. Those of us who still have all of our senses might sometimes have a hard time separating them and we may not notice that we’re conscious of the expected acoustic properties of a room until they’re altered somehow. It’s possible, for instance, to make a small room sound like a larger one and people will easily notice that something seems “off” when the look of a place doesn’t match the sound.

Of course, these everyday experiences are a far cry from the abilities of the most highly skilled blind echolocators out there. While not exactly common, there are enough accounts of totally blind people being able to walk around effortlessly without using a cane or any other device to establish that object detection using only the sense of hearing is indeed possible. Using everything from the ambient sound in a room to the person’s own footsteps or self-produced sounds (most commonly tongue clicks or a snap of the fingers), it is possible to locate larger objects and even determine their shape and what material they’re made of from several feet away. Though not everyone is able to attain a very high level of skill, echolocation can be learned by just about anyone.

Since the phenomenon of echolocation first garnered serious scientific investigation, it’s been assumed that the higher frequencies (above 8,000-10,000 Hz) are the most important for object detection. This may be in part because mammals that use echolocation, such as bats and dolphins, use high frequency sounds. High frequency sounds are also better for detecting smaller details because of their shorter wavelength, and much of the early research seemed to confirm their importance for echolocation in humans.

In the last decade, however, low-frequency sounds have shown to be worthy of a second look, particularly when it comes to the perception of large features such as walls and buildings. It’s been demonstrated that there is a so-called spectral shift due to the tendency for the background sound of a room to be different in sound pressure near walls compared to the middle of the room. This is much more noticeable for lower frequencies than for higher ones and allows for people to literally hear the presence of a wall when moving toward it. For lower frequencies, this translates into a distance of 3-6 feet (1-2 m).

Echolocation and superhearing

If we insert my previous hypothesis that Matt Murdock is able to hear higher frequencies than the normal human, as well as being much more sensitive to lower frequencies (where normal humans don’t do very well at all), his ability to use echolocation would be enhanced in some crucial ways. His ability to detect the presence of large features of the landscape would increase many-fold to the point where actually “feeling” both rows of buildings on either side of the road sounds plausible. Since much of the ambient sound available for detecting objects – in the case where a person doesn’t rely on self-produced sounds – happens to be lower frequency sound, this ability is further supported.

Better access to high frequency sounds would have other benefits. There aren’t as many of these just floating around, but higher frequencies allow for much finer detail. Another thing to keep in mind is that, aside from better echolocation, Matt would have a huge advantage over regular blind people due to his generally heightened sense of hearing. He’d be able to hear exactly where people are, be much better attuned to the location of machinery and other sources of sound and just have much more information at his disposal.

In the comic, Daredevil’s radar is often utilized on an “as needed” basis. Some writers have probably imagined that this ability is something he’s tuned into every waking minute, but instances of his sensing something only after having first used his other senses are very common. One of the more extreme examples of Matt sequentially analyzing a scene comes from Daredevil #104 (vol 2), by Ed Brubaker and Michael Lark.

Matt comes home, panels from Daredevil (vol 2) #104.

While this scene might seem extreme (personally, I think the smell of blood should have been the single most noticeable thing about his coming home), it does make sense that he’d take in a scene in a different way than a normal-sensed sighted person would. Vision is such an important sense to humans that it’s difficult to imagine it taking a backseat to other impressions. Approaching this scene from a “radar as echolocation” perspective, I also have no problem imagining this ability as consisting of a subset of abilities which require varying amounts of concentration and effort.

A general sense of being near an object or wall might require no effort at all and be a constant feeling as obvious as seeing and hearing, whereas eliciting a more detailed pseudo-visual experience of objects farther away than ten or fifteen feet would possibly require actual focus and depend on a different kind of analysis of the soundscape around him. There is no way of knowing how a human brain would react to being inside the head of a blind person with dramatically enhanced hearing, but this kind of layered approach would be consistent with Daredevil’s history of never walking into anything while not always “seeing” something right away.

Conclusion

The way I see it, the “radar as echolocation” hypothesis (wow, doesn’t that sound pretentious?) has several things going for it. First of all, not having to rely on a novel sense which would be dependent on an unknown energy source is more elegant and feels much less like the “cheat” I’ve occasionally seen the radar sense described as. It is also clear that some normal blind humans have, in fact, developed such an impressive ability in the absence of superpowers that adding extremely heightened hearing to the mix would push this skill to new extremes. This interpretation of the radar sense also fits the comic book well, and actually makes more sense given Daredevil’s strengths and weaknesses. It would explain why excessive and chaotic noise is such a nuisance.

I would love to hear what my fellow science geeks think about this subject. And, if you’re interested in learning more, I recommend Kuljit Mithra’s interview with Daniel Kish, a blind echolocation expert (you can find it in the Interviews section on ManWithoutFear.com) as well as all of the various YouTube clips available of the now deceased blind wunderkind Ben Underwood.