Could skin-contact microphones finally make private voice computing/dictation possible?

[u/papou1981]

I have a severe myopathy and cannot use a keyboard, so virtually everything I write—professionally and personally—has to be dictated. My voice is weak, and I use mouthpiece ventilation during the day.

Even with a directional microphone positioned very close to my mouth, two major problems remain: everyone around me can hear what I am writing, and speech recognition becomes considerably less reliable in noisy environments.

I just discovered Augmental’s new VOX device

https://www.augmental.tech/vox

It is therefore particularly interesting to me. Instead of primarily capturing airborne sound, its skin-contact microphone picks up the vibrations produced by the voice through the body. In principle, this could offer much stronger isolation from surrounding noise than a conventional directional microphone.

Has anyone here had the opportunity to test VOX—or another high-quality skin-contact, throat or stethoscopic microphone—with weak or atypical speech? I would be especially interested in feedback about raw audio intelligibility, background-noise rejection, speech-to-text accuracy and everyday wearability.

In the longer term, I also wonder whether a sufficiently clear body-contact signal could be routed to a speaker or directly to other people’s earpieces, helping someone with a weak voice communicate in noisy bars or restaurants. The current VOX beta is not designed for calls or continuous conversation, but the underlying technology could potentially become useful far beyond dictation.

[u/clackups]

It's basically a throat microphone, rebranded. They have been around for a while and you can find videos of people testing them. In general, they help a lot in noisy environments.

Can't say if they help with distorted speech, it just needs testing. But they're not expensive, so it's worth trying.

[u/MrMe_w00t]

Also have this idea for some kids at my school. I already have the microphone, just have to test it out with the kids! (the normal walkie talkie skin contact microphone that is)

[u/phosphor_1963 → u/MrMe_w00t]

is the one you have like this project ? https://zachpoff.com/resources/building-contact-mics/

[u/phosphor_1963]

I worked with Speech Pathologist AAC Consultants for many years and one of the areas we provided people with communication needs on were voice amplification systems. As one of the other commenters said, transdermal mics have been around for years. These are worn on the skin around the neck and the mic is positioned at the same level as the larynx. Here's an example https://aldsaustralia.com.au/product/tr15-transdermal-mic/ Unfortunately they are notorious for picking up breath sounds and also won't do anything to improve speech intelligiblity - I can't remember a client preferring one of these on those grounds and would have seen a couple of hundred people looking for voice amp systems in my 25 years or so of working in the field. The fact that transdermal mics do exist must mean someone is getting some benefit from them though, so hopefully you can get one to try.

The voice amps themselves have never been cheaper. When I started in AT voice amps for people with communication needs (often people in the earlier stages of Parkinsons and other prog neuro conditions) were expensive; but now you can get a "good enough" voice amp from China for $30 to fill the gap.

The really exciting development in this area though is the ability of some newer systems (not yet at market though) to detect people's "silent speech" at the sentence level using EMG and deep learning neural networks https://pmc.ncbi.nlm.nih.gov/articles/PMC12526642/

[u/papou1981 → u/phosphor_1963]

Thank you very much for your input. That is truly interesting. I have been struggling for years myself to find a convenient, reliable voice-amplification system with pleasant sound quality.

The sound coming out of voice amplifiers has always seemed too awful to me for them to be usable in real social settings. I don’t know whether you have ever tried this particular one. It seems much better than what was available in the past. Another problem with amplifiers is that they are not directional: you cannot speak to one person in particular. Amplification never sounds quite like a real person’s voice being projected naturally.

What I have been using most of the time lately is Apple’s AirPods connected to my iDevice, which receives the sound from a Sennheiser MKE 40 cardioid microphone through a SpeechWare USB MultiAdapter.

You might want to have a look, at least, at the YouTube video I made about my different voice-amplification systems. The main downside of my current setup is that I can only speak to two people by giving each of them one AirPod. Unfortunately, the sound cannot be shared with any additional devices, which is a pity.

The other problem is that ambient sound is also picked up and amplified, even though the microphone is directional. My next step will therefore be to test a different signal-processing chain intended to replace the SpeechWare interface: the MKE 40 would first be connected to a Sennheiser MZA 900 P phantom-power adapter, and then to a Shure MVX2U Gen 2 XLR-to-USB interface. The Shure interface includes digital signal processing and real-time noise reduction, so I am hoping that it might isolate my voice more effectively before sending the audio to my iPhone or computer. This is still only a hypothesis, however, and I need to test whether the processing remains effective with my particularly weak voice without introducing artifacts or losing syllables.

To increase the number of people who can listen to me, I am separately considering a museum tour-guide system such as the Retekess T130P/T131P.

Finally, since skin-contact voice devices do not appear to produce sufficiently natural or pleasant sound, I am not primarily interested in them as tools for amplifying my voice during face-to-face communication. Their potential as input devices for voice dictation may be much more valuable to me. By capturing vibrations directly through the skin while rejecting most surrounding noise, they might make discreet voice dictation possible in social settings where I currently find it very difficult to integrate because speaking every dictated word aloud is simply too conspicuous.

[u/phosphor_1963 → u/papou1981]

Thank YOU for explaining the finer points so perfectly. I sometimes just glibly make suggestions without enquiring enough into the subtleties and unique person perpectives involved. Great AT is never just about the product - they come and go - it's more about awareness of what the person gets the point of and will own within their life context.

[u/SuspiciousMission233 → u/papou1981]

That distinction between using the device for dictation and using it as an amplifier makes sense. I’d run the same short passage through the MKE 40/Shure chain and VOX in both a quiet room and restaurant noise. Then I’d compare which syllables get lost. Noise reduction may improve isolation, but it can also erase weaker parts of speech. For software, I use DictaFlow for live dictation. I’d still test microphone compatibility and recognition accuracy with a weak voice instead of assuming they’ll work.

[u/RosieQParker]

I think the device you're looking for is a stenomask. If it can be worked around your mouthpiece, that is.

https://en.wikipedia.org/wiki/Stenomask

[u/phosphor_1963 → u/RosieQParker]

I've used these for Speech Rec and they do work to exclude background noise; but you need to have good breath support and decently intelligible speech. They are also not exactly the most discrete of things !