Audio Algorithms for Enhanced Conversation and Listening
From remote work and learning to leisure viewing and listening, earbuds and headphones have achieved ubiquity across diverse applications, with noise cancellation algorithms, voice calling, and sound quality improvements adding more sophistication to every generation of audio products on the market. The past few years have seen dramatic improvements to connectivity and battery life as well as a proliferation of features like adaptive noise cancellation and spatial audio.
However, even with all this advanced functionality, there is still significant opportunity for earbud and headphone makers to achieve differentiation through improved voice calling quality. Beyond that, there is potential to evolve from headphones into dynamic devices that offer life enhancements from personal sound amplification to health monitoring. Analog Devices, Inc. (ADI) offers a suite of audio processing algorithms that support crystal clear telephony and next-generation hearing augmentation functionality.
Context Aware Hearable Solutions
Learn about some of ADI's most recent innovations for hearables at CES 2023
ADI LISTN Pure Voice (PV)
Voice calling remains one of the most power-hungry applications on an earbud. Space constraints necessitate compromise, and there is no silver bullet to solve the challenge of background noise. Whether it’s letting too much noise in, distorting the user’s own voice, or inconsistent voice capture through the voice assistant interface, even the most high-end true wireless stereo (TWS) earbuds with the most sophisticated voice accelerometers usually leave some performance to be desired.
ADI LISTN Pure Voice (PV) is an audio algorithm that leverages in-ear inward-facing microphones and, optionally, bone vibration sensors to offer excellent voice preservation and noise suppression that elevate voice calling quality on TWS earbuds, all within a very small footprint.
In-ear microphones are used for feedback noise cancellation and are getting more popular with the increasing presence of hybrid ANC. Bone vibration sensors are also used in high-end earbuds from major name brands. The PV audio algorithm automatically adapts to support earbud designs that make use of both microphones and bone vibration sensors.
Wind noise can be a particularly big challenge for telephony. The PV audio algorithm works to reduce this noise source, with demonstrable improvements. In many environments, voice preservation is near perfect while offering almost full and instantaneous noise suppression.
ADI LISTN Hearing Augmentation (HA)
Even people with little to no hearing loss often face noisy environments where conversations are challenging. For example, it can be difficult to pick out a single voice in a crowded restaurant with many other voices overlapping nearby. By combining techniques used in expensive medical-grade hearing aids with today’s highly integrated and powerful consumer TWS chips, earbud makers can greatly improve listening conditions to make conversations crisp and clear.
ADI LISTN integrates hearing augmentation (HA) into the existing audio path and leverages isolation features available on the earbud, usually a combination of active noise cancellation (ANC) in low frequencies (< 2kHz) and passive attenuation (or insertion loss) above. ADI’s suite of hearing augmentation (HA) signal processing algorithms enables earbud users to control exactly what and how they hear in day-to-day settings: Noisy restaurants, quiet presentations, and blended environments where a combination of noise cancellation and transparency may be important, such as listening to music while jogging near traffic.
Passive Isolation and Noise Cancellation
Thanks to advancements in hardware latency, design, and tuning, earbuds can now deliver ever stronger noise cancellation. However, users sometimes want the opposite effect of being able to hear and socialize without removing their earbuds. Premium earbuds today offer adaptive noise cancellation, setting the sound scene somewhere between transparency and isolation and/ or ensuring maximum ANC performance for all fits.
Hearing Augmentation Modes
The ADI LISTN Hearing Augmentation (HA) mode enables extended perception with controllable amplification, beamforming, and real-time noise reduction. Meanwhile, voice focus mode enhances the speech spectrum to narrow down the listening sphere for crystal clear conversations. ADI’s HA software supports smart switching between functions and modes in response to triggers such as the user’s voice indicating the start of a conversation.
Not Your Grandparent’s Hearing Aid
Personal sound amplification, noise reduction, and speech enhancement add high-end differentiating features to an earbud product in a crowded market without the stigma of wearing a medical device. Having these features integrated into TWS earbuds that might be carried around all day for music and phone calls means that this augmented hearing capability is always available when needed but doesn’t require a dedicated device.
Close to 30 million adults living in the U.S. have some degree of hearing loss. Despite the high number of people affected by hearing loss, only about one-fifth of those who could benefit from a hearing aid seek intervention.
Using hearing aids may reduce the frequency or severity of cognitive decline, depression, and other health problems in adults. Added benefits can include improved social participation and a better quality of life.
U.S. Food & Drug Administration
[source: https://www.fda.gov/medical-devices/hearing-aids/otc-hearing-aids-what-you-should-know]
ADI LISTN and the Future of Augmented Hearing
Already, the hearable industry is witnessing nascent market traction for augmented hearing features, with key devices providing proof of concept in the early days of this trend. Going forward, we see convergence happening towards augmented and mixed or extended reality (AR and XR) and the Metaverse with Machine Learning for vision, depth, spectral and light sensing.
With a three-prong legacy in health monitoring, vision, and audio technologies, ADI is ideally positioned for the exciting future of augmented sensing in earbuds, VR headsets, and AR glasses.
Featured Products
ADI LSTN Pure Voice and Hearing Augmentation algorithms are available on ADAU1860.
ADAU1860
The ADAU1860 is a codec with three inputs and one output that incorporates two digital signal processors (DSPs). The path from the analog input to the DSP core to the analog output is optimized for low latency and is ideal for noise canceling earbuds and headphones. With the addition of just a few passive components, the ADAU1860 provides a complete hearable solution.
ADAU1860 EV Kit
The EVAL-ADAU1860EBZ provides access to all the analog and digital inputs and outputs on the ADAU1860. The ADAU1860 core is controlled by Analog Devices, Inc., Lark StudioTM software, which interfaces to the EVAL-ADAU1860EBZ via a USB connection. In addition, users can communicate and debug with the Tensilica HiFi 3z DSP core through the JTAG port by using the mIDAS-Link emulator. The software development kit (SDK) is also provided by Analog Devices for code development.
