Written by: Audiotelligence
Access all areas: smartphones and assistive listening
Back in the day, a phone was just that – a device for making voice calls. Now the device in our pockets is a hugely powerful computer which can perform around 11 trillion operations per second – over 5,000 times faster than a 1980s supercomputer. We have myriad ways of accessing almost every type of media and of communicating with each other and with the world around us, sitting in the palm of our hands. And it’s all so easy.
Easy for most of us. But what about people with hearing loss? Many people who may not have a need for hearing aids nevertheless find that with age they start to have difficulties with hearing – especially the higher frequencies of sound. Of course it’s possible to communicate on a smartphone without sound, via messaging or the almost ubiquitous Whats app, but these have their limitations. Fortunately, awareness of hearing impairment and its impact on people’s lives is growing, and the smartphone companies have been keen to improve accessibility for the hearing impaired on their products.
To start with, consider how someone with hearing impairment knows that they have a phone call or message if they can’t hear the ringtone. Features on smartphones can use our other senses to alert us: touch for vibration and sight for flash alerts. These flash alerts can also be programmed to notify users of important sounds or alarms – door bells, smoke alarms, baby crying, and breaking glass to name just a few. The smartphone becomes not just a tool, but potentially a life saver.
Once the phone is in use, users with hearing impairment need to have either improved sound from their phone or a method of using it without any sound at all. The ‘no sound’ option is catered for by the accessibility feature that most of us will be aware of – closed captioning. This is the provision of captioning for videos, movies or TV shows that are being streamed or downloaded onto the phone. Reading words on the screen is a great option if the user either has severe hearing loss, or is using the phone in a very noisy environment where the background noise makes things difficult even for someone with normal hearing.
The caption concept is now being taken a step further, with captions for any audio or video played, including content from web pages and podcasts, and live speech from conversations. This has received some mixed feedback so far, with Hearing Health Matters reporting that Apple’s version had particular trouble decoding speech in background noise. The Live Transcribe app is an equivalent offering from Google. Place the phone next to the person talking, and the app will transcribe their speech into text displayed on the phone’s screen. This works in group settings with multiple people speaking; it can also be used with speech from TVs or computers, but is less accurate.
If the user just wants to hear more clearly, sound amplifier apps may be the solution. They are now widely available and are intended to reduce background noise, amplify quieter sounds and boost high or low frequencies.
For example Apple’s Live Listen, which was introduced with iOS 12, uses the iPhone’s microphone to amplify sound and send it directly to a user’s TWS earbuds or hearing aid. This means that users can hear conversations, lectures, or other audio sources more clearly, even in noisy environments. Live Listen is also customisable, allowing users to adjust the volume and sensitivity of the microphone to suit their individual needs.
Google has a similar feature called Sound Amplifier, which is available on Android devices running version 6.0 or higher and which works with either wired headphones or wireless earbuds. Sound Amplifier uses the device’s microphone to enhance sound in real-time, filtering out background noise and boosting speech frequencies. Users can customise the settings to adjust the amplification levels and noise reduction filters.
Samsung phones also come equipped with a range of accessibility features. One of these amplifies ambient sound – where you can focus on a conversation even when you’re somewhere noisy.
All of these are features which are useful for anyone who is trying to hear in a noisy place, or who is beginning to have some hearing loss. But to work well, they all depend on the quality of the audio processing done by the phone. How good are they?
We are passionate about helping people hear clearly in noise, so that everyone can participate fully in the world around them. So we’ve done extensive testing and benchmarking of these conversation enhancement features on iOS and Android phones. To achieve a fair comparison, we had to test these features in a controlled environment, rather than simply using them in random noisy situations in real life. We set up 8 speakers to play background noise at 70dB; we simulated a conversation in this noisy environment with two speakers playing speech – one was the ‘target speaker’ whose voice we wanted to listen to, the other was the ‘interferer’ whose voice we did not want to hear. These two speakers played at 73dB, giving the test environment an SNR of 3dB.
On the whole, we found these features worked fairly well in the test environment for simulated one to one conversations in about 65 dB of noise. With only one of our speakers talking, they did provide some benefit by reducing the ambient noise. But in the more complex test environment, when we introduced the interfering speaker, to simulate a conversation with multiple people talking (which after all is the more likely scenario in a lively social setting) they did not succeed in cancelling the voice from the interfering speaker – so they did not perform much better than with the feature turned off. It’s possible to turn up the noise suppression on these apps, but we noticed that as we did so, we could hear more artefacts and distortion in the voices. This made the listening experience not only artificial, but also rather annoying.
So what’s the answer? We believe that these features are a good starting point, but they need improvement to be really useful. Because it was developed specifically to help with hearing in noise, AudioTelligences’ aiso™ technology can solve the problem.
Aiso™ improves speech understanding in noise from 5% to 98%. It allows the user to choose one voice among several and hear it clearly, even in environments where the background noise is up to 75dB – that’s the equivalent of a very noisy cafe or restaurant. Adding aiso™ to the existing technology on smartphones really would allow the hard of hearing to access all areas of the world of sound.