Penn State engineers have devised a circuit inspired by the way barn owls can so precisely determine where a sound is coming from and track their prey in the dark. Eventually, this fine example of biomimicry could lead to more accurate electronic navigation devices. Essentially, the owl's brain calculates the difference between when a sound arrives at the left ear compared to the right ear and uses that information to locate the source of the sound. After that is when things get interesting. From Penn State:

The speed of sound is faster than the owl's nerves can function so after the owl brain converts the sound to an electrical pulse, the pulse is slowed down. Then the brain's circuitry uses a lattice of nerves of different lengths with inputs from two ends, to determine which length is where the two signals coincide or arrive at the same time. This provides the direction.

Saptarshi Das and his team have created an electronic circuit that can slow down the input signals and determine the coincidence point, mimicking the working of the barn owl brain...

The team created a series of split-gate molybdenum sulfide transistors to mimic the coincidence nerve network in the owl's brain. Split-gate transistors only produce output when both sides of the gate match, so only the gate tuned to a specific length will register the sound. The biomimetic circuitry also uses a time-delay mechanism to slow down the signal...

"Millions of years of evolution in the animal kingdom have ensured that only the most efficient materials and structures have survived," said Sarbashis Das.

A woman in China reportedly suffering from a rare medical condition supposedly can't hear male voices. Most hearing loss occurs at higher frequencies when the delicate hair-like stereocilia of the inner ear are damaged, but this woman has the much less common reverse-slope hearing loss (RSHL) that affects the ability to hear lower frequencies. From LiveScience:

At the hospital, Chen was treated by Dr. Lin Xiaoqing — a woman — who noted that while Chen was able to hear Xiaoqing's voice, she couldn't hear the voice of a nearby male patient "at all," according to Newsweek. Xiaoqing diagnosed Chen with reverse-slope hearing loss, a rare type of low-frequency hearing loss that likely impaired her ability to hear deep male voices....

Loss of hearing of lower-pitched sounds (which is what Chen experienced) is... less common because the bass-processing portion of the cochlea — a snail-shaped structure deep in the inner ear — is very well protected, said Jackie Clark, a clinical professor with the School of Behavioral and Brain Sciences at the University of Texas at Dallas, who also wasn't involved with Chen's case...

"Most studies have shown that if you catch it within 48 hours, you have the best chance for recovery," (Clark) said.

illustration: Morten Bisgaard - From the book "Tidens naturlære" 1903 by Poul la Cour Read the rest

Get your game on, go play. (AsapSCIENCE)

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According to her mom, blogger Christy Keane, baby Charly was born "profoundly deaf." In this truly heartwarming video, you'll see this precious child responding to her mom's voice for the first time ever through the miracle of hearing aids.

Charly gets quite emotional and seems unsure whether to smile or cry. Who can blame her?

On Instagram, Keane writes, "We didn't think she would hear anything so this was more incredible than I can put in to words."

Oh, my heart.

(Neatorama) Read the rest

University of California San Diego engineer Timothy O’Connor led a team that developed a smart glove that turns the American Sign Language alphabet into text. The project used inexpensive off-the-shelf products totalling about $100. Read the rest

Water is viscous. With heat, the viscosity drops. And you can hear the difference in its splash.

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Scientists conducting research into hearing loss have come across a compound the regenerates cochlear hair cells, which could lead to a cure for certain kinds of deafness.

From C&EN:

The snail-shell-shaped cochlea of the inner ear contains some 15,000 hair cells that are needed for humans to hear. Audiologist dogma holds that once these cells die off, they never grow back, leading to hearing loss.

But a new study suggests that hair cell death may not be as immutable as it seems. Scientists from Harvard, MIT, Brigham & Women’s Hospital, and Massachusetts Eye & Ear Infirmary have discovered a mixture of molecules that can dramatically reverse hair cell loss in the cochleas of mice.

Lip-reading algorithms have all sorts of real-world applications, and LipNet shows great promise in machine-learning lipreading of constructed sentences from the GRID sentence corpus. Read the rest

Carryl Baldwin, a professor of cognition and applied auditory research, designs and tests sounds for "use as alarms in household, aviation, medical, and automotive settings." Atlas Obscura explores the art and science of making sounds that convey a spectrum of urgency:

One of the main considerations is the annoyance factor. To test for annoyance in the lab, says Baldwin, “we’ll construct sounds and we’ll look at all of the different acoustic parameters, so we might vary, for instance, intensity, frequency, the number of harmonics, how fast it ramps up and down, the temporal characteristics—like whether it’s going d-d-d-d-d-duh rapidly or duhhhh-duhhhhh-duhhhh.”

The faster an alarm goes, the more urgent it tends to sound. And in terms of pitch, alarms start high. Most adults can hear sounds between 20 Hz and 20,000 Hz—Baldwin uses 1,000 Hz as a base frequency, which is at the bottom of the range of human speech. Above 20,000 Hz, she says, an alarm ”starts sounding not really urgent, but like a squeak.”

Harmonics are also important. To be perceived as urgent, an alarm needs to have two or more notes rather than being a pure tone, “otherwise it can sound almost angelic and soothing,” says Baldwin. “It needs to be more complex and kind of harsh.” An example of this harshness is the alarm sound that plays on TVs across the U.S. as part of the Emergency Alert System. The discordant noise is synonymous with impending doom.

"An Alarm Designer on How to Annoy People in the Most Effective Ways" (Atlas Obscura) Read the rest

Directed by David Terry Fine and based on the essay "Seeing at the Speed of Sound" by Rachel Kolb, who narrates this short film.

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Do you have kids? Here’s my advice – get these headphones by Puro Sound Labs. You won’t regret it. The number one reason to get them is for their volume-limiting ear protection. According to the National Institute on Deafness and Other Communication Disorders, “As many as 16 percent of teens (ages 12 to 19) have reported some hearing loss that could have been caused by loud noise.” And the Hearing Health Foundation says “…the problem is listening to MP3 players through earphones turned all the way up.” These headphones keep the volume below 85 dBA, the safety limit established by the CDC (Centers for Disease Control and Prevention).

The headphone cups and cushioning are designed to greatly reduce background noise so that your kids can listen to music and videos without having to turn up the volume to compete with traffic, airplane noise, and other sounds.

The ear safety features are reason enough to buy the headphones, but thier other features are also compelling. They have built-in Bluetooth, so no cord is needed (it comes with a cord in case you want to use the headphones with a non-Bluetooth media player). They will run for 18 hours on a single charge. They are also lightweight and made with attractive materials. They don’t look like a kid product - they are elegant and I like using them, too (though it’s a bit of a stretch to get them around my fat head). The sound quality is excellent, too. They are pre-tuned to sound their best on iOS (you can download an equalizer app to change the sound characteristics). Read the rest

WHYY's The Pulse radio show visited The Franklin Institute's new exhibition "Your Brain" where chief bioscientist Jayatri Das demonstrated an incredible audio illusion. Read the rest

This video explains the weirdness of the McGurk effect, a perceptual illusion demonstrating that understanding speech is not just about what we hear, but also what we see. You can learn more about the McGurk effect at Yale's Haskins Laboratories dedicated to the science of the spoken and written wordl. (via Imaginary Foundation) Read the rest

[Video Link] From H. Hoover at Distriction blog, a little anecdote about a cool interaction that Stephon, a young man who was "born deaf and justifiably proud," had with the president at a recent event:

Stephon stood just a few feet away from Barack Obama. The president, busy shaking hands, looked right at him. “It was like he was waiting for me to say something,” he said later.

So the 26-year-old Prince George’s Community College student took his cue and spoke to President Obama in his first language: American Sign Language. “I am proud of you,” Stephon signed. The president, almost involuntary, instinctively, immediately signed back.

“Thank you,” Obama replied.

The whole story is a nice little read.

This has nothing to do with the neat story behind this video, but I've always wondered: is being bald and steely-eyed a requirement for Secret Service agents? I mean, is it in the job description? And if they're not already bald, do they make them shave their heads? Because it seems like every one I've seen in real life, and in this video, is a steely-eyed bald guy. Someone please get back to me on that. Thanks.

(via Steve Silberman) Read the rest

[Video Link] sloanchurman says: "I was born deaf and 8 weeks ago I received a hearing implant. This is the video of them turning it on and me hearing myself for the first time :)" (Via Sean Bonner) Read the rest