Hearing loss is a common problem for many – especially those who may have attended too many loud concerts in their youth. [mircemk] had recently been for a hearing test, and noticed that the procedure was actually quite straightforward. Armed with this knowledge, he decided to build his own test system and document it for others to use.
By using an Arduino to produce tones of various stepped frequencies, and gradually increasing the volume until the test subject can detect the tone, it is possible to plot an audiogram of hearing threshold sensitivity. Testing each ear individually allows a comparison between one side and the other.
[mircemk] has built a nice miniature cabinet that holds an 8×8 matrix of WS2812 addressable RGB LEDs. A 128×64 pixel OLED display provides user instructions, and a rotary encoder with push-button serves as the user input.
Of course, this is not a calibrated professional piece of test equipment, and a lot will depend on the quality of the earpiece used. However, as a way to check for gross hearing issues, and as an interesting experiment, it holds a lot of promise.
There is even an extension, including a Class D audio amplifier, that allows the use of bone-conduction earpieces to help narrow down the cause of hearing loss further.
It’s a news story that’s flashed around the world and like most readers we’re somewhat fascinated by the lengths to which they seem to have been prepared to go, but it’s left us with a few unanswered questions. The news reports all have no information about the devices used, and beyond the sensationalism of the story we’re left wondering what the practicalities might be.
Implanting anything is a risky and painful business, and while we’ve seen Bluetooth headphones and headsets of all shapes and sizes it’s hardly as though they’re readily available in a medically safe and sterile product. Either there’s a substantial rat to be smelled, or the device in question differs slightly from what the headlines would lead us to expect.
A lot of our projects make noise. It can be something as simple as a microcontroller driving a small speaker or a truly ambitious Hi-Fi project, but common to all of them is the desire to get that sound out in as audible and high-quality a manner as possible. We’ve been known to make fun of the more preposterous side of the Hi-Fi world at times, but behind it all there’s a basis of solid and provable audio engineering that can be brought to bear on almost any project involving sound and electronics. Perhaps it’s time to devote some time to a series exploring the topic, and what better place to start than the ultimate destination for all that sound. Any Hi-Fi is only as good as the ears of the person listening to it, so in out journey through the world of audio that’s where we’ll start. Continue reading “Know Audio: Start At The Very Beginning”→
We are accustomed to medical devices being expensive, but sometimes the costs seem to far exceed reasonable expectations. At its most simplistic, a hearing aid should just be a battery, microphone, amplifier, and speaker, all wrapped in an enclosure, right? These kinds of parts can be had for a few dimes, so why do modern hearing aids cost thousands of dollars, and why can’t they seem to go down in price?
If you’ve ever seen an experienced radio operator pull a signal out of the noise, or talked to someone in a crowded noisy restaurant, you know the human brain is excellent at focusing on a particular sound. This is sometimes called the cocktail party effect and if you wear a hearing aid, this doesn’t work as well because the device amplifies everything the same. A German company, Fraunhofer, aims to change that. They’ve demonstrated a hearing aid that uses EEG sensors to determine what you are trying to hear. Then it uses that information to configure beamforming microphone arrays to focus in on the sound you want to hear.
In addition to electronically focusing sound, the device stimulates your brain using transcranial electrostimulation. A low-level electrical signal tied to the audio input directly stimulates the auditory cortex of your brain and reportedly improves intelligibility.
Assistive technology is extremely fertile ground for hackers to make a difference, because of the unique requirements of each user and the high costs of commercial solutions. [Nick] has been working on Earswitch, an innovative assistive tech switch that can be actuated using voluntary movement of the middle ear muscle.
Most people don’t know they can contract their middle ear muscle, technically called the tensor tympani, but will recognise it as a rumbling sound or muffling effect of your hearing when yawning or tightly closing eyes. Its function is actually to protect your hearing from loud sounds screaming or chewing. [Nick] ran a survey and found that 75% can consciously contract the tensor tympani and 17% of can do it in isolation from other movements. Using a cheap USB auroscope (an ear camera like the one [Jenny] reviewed in November), he was able to detect the movement using iSpy, an open source software package meant for video surveillance. The output from iSpy is used to control Grid3, a commercial assistive technology software package. [Nick] also envisions the technology being used as a control interface for consumer electronics via earphones.
With the proof of concept done, [Nick] is looking at ways to make the tech more practical to actually use, possibly with a CMOS camera module inside a standard noise canceling headphones. Simpler optical sensors like reflectance or time-of-flight are also options being investigated. If you have suggestions for or possible use case, drop by on the project page.
Assistive tech always makes for interesting hacks. We recently saw a robotic arm that helps people feed themselves, and the 2017 Hackaday Prize has an entire stage that was focused on assistive technology.
We are swimming in radio transmissions from all around, and if you live above the ground floor, they are coming at you from below as well. Humans do not have a sensory organ for recognizing radio signals, but we have lots of hardware which can make sense of it. The chances are good that you are looking at one such device right now. [Frank Swain] has leaped from merely accepting the omnipresent signals from WiFi routers and portable devices to listening in on them. The audio signals are mere soundwaves, so he is not listening to every tweet and email password, merely a representation of the data’s presence. There is a sample below the break, and it sounds like a Geiger counter playing PIN•BOT.
We experience only the most minuscule sliver of information coming at us at any given moment. Machines to hack that gap are not had to find on these pages so [Frank] is in good company. Magnetosensory is a popular choice for people with a poor sense of direction. Echolocation is perfect for fans of Daredevil. Delivering new sensations could be easier than ever with high-resolution tactile displays. Detect some rather intimate data with ‘SHE BON.’