SONNET 2 Audio Processor

Don’t fit your life around an audio processor—choose a processor that fits your life! Whatever your lifestyle, SONNET 2 is made for you. Wear it the way you want to. Connect it to the phone you already have. And experience great sound quality, whatever you’re doing.

SONNET 2 - Smart Sound Technology

Easy Listening

SONNET 2 is designed to give you your best hearing possible, wherever you are. Whether in a noisy restaurant, at a music concert, or simply taking a walk on a windy day, SONNET 2 lets you hear your best in any environment.


Adaptive Intelligence

SONNET 2 recognizes what kind of environment you’re in and automatically adjusts settings to match. Best of all, you won’t even realize it’s happening.

Noise Reduction

From background noise in a café, to an unexpected dog bark, SONNET 2 minimizes unnecessary noise, so you can have the confidence to chat in any environment.


Hear the details with FineHearing sound coding technology. FineHearing lets you hear the world as it was meant to sound—from your favorite song to the voice of a loved one.

SONNET 2 - Easy Listening
SONNET 2 - AudioStream

Simple Streaming

Use the phone you like and connect it to the audio processor you love. SONNET 2 makes it easy to listen to your favorite music and enjoy phone calls with your loved ones in high-quality, true stereo. Just slide the AudioStream cover over your audio processor to enjoy direct wireless streaming from your smartphone or tablet.


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AudioStream - Bimodal Streaming

Made for Bimodal

Use a hearing aid on one of your ears? No problem! SONNET 2 is compatible with every brand and type of hearing aid because our implant systems mimic natural hearing. And if your hearing aid supports audio streaming, you can even stream sound to both your ears at the same time. All you need is AudioStream and a compatible smartphone.

Is my phone or tablet compatible with bimodal streaming with AudioStream?

Bimodal Streaming

SONNET 2. Made For You.

Want to know how SONNET 2 fits your lifestyle?
Take our 5 minute quiz and find out!


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SONNET 2 and AudioKey


Be In Control

Gone are the days of carrying around a remote control. With the new AudioKey 2 app, you can change settings on your SONNET 2 directly from your phone. Volume, mic sensitivity, program selection—all at the press of a button.

What’s more, AudioKey 2 also lets you see your individual hearing stats, such as how long you wear your SONNET 2 each day. And if you unexpectedly lose your processor, the "Find My Processor" function shows where you last used the app with your audio processor, so you can retrace your steps.


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AudioKey is available in areas where AudioKey 2 is not. Please contact your local MED-EL representative for more information.

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SONNET 2 - Style
SONNET 2 - Style

Match Your Style

Style your SONNET 2 to match your individual look. With thousands of colour combinations to choose from, you really can give your SONNET 2 a unique makeover!

Visit the SONNET Series Colour Configurator and start designing your personal SONNET 2.


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Design Award 2019

Awarded to the SYNCHRONY System, comprising the SONNET 2 Audio Processor and accessories, SYNCHRONY Cochlear Implant, and MAESTRO 8.0 fitting software.

SONNET 2 - water-resistant
SONNET 2 WaterWear

Splash Around

With SONNET 2, you can get caught in the rain! SONNET 2’s water-resistant design protects it from everyday splashes and moisture. Going for a run in the rain just got a little bit easier.

And for swimming or other water sports, the waterproof WaterWear covers are ideal! Simply slip the cover over your processor and enjoy hours of hearing fun in the pool or at the beach.


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SONNET 2 - For Kids
SONNET 2 - for kids

For Kids

Choosing the right audio processor for your child can be hard. SONNET 2’s compact and durable design makes it the ideal choice for children—from their first birthday right through their teens and beyond.

SONNET 2 - Long-Lasting Power
SONNET 2 - Long-Lasting Power

Long-Lasting Power

SONNET 2’s powerful batteries mean you can go for days at a time. Choose regular zinc-air disposable batteries for the longest wearing time. Alternatively, the rechargeable batteries are a convenient way to keep SONNET 2 powered up throughout the day.


SYNCHRONY 2 Cochlear Implant

Great sound quality is only possible with a great implant. With SYNCHRONY 2 you can benefit from the latest cochlear implant technology and our MRI Guarantee.

But the biggest advantage of SYNCHRONY 2 is that it mimics natural hearing. The result? The closest to natural hearing of any cochlear implant system.

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Technical Data


Width: 37.4mm
Height: 67.6mm with Battery Pack Cover Max
Height: 56.7mm with Battery Pack Cover Standard
Height: 51.4mm with Battery Pack Cover Micro
SONNET Audio Processor Size
Thickness: 5.9mm
Thickness: 9.3mm

Audio Processor

Weight and Dimensions

  • 6.1 g (with ActiveWear)
  • 10.6 g (with two 675 zinc-air batteries)
  • DL-Coil: 4.6 g, 32.8 mm x 5.8 mm
  • DL-Coil: 5 magnets available in 9 strengths
  • Durable coil cables available in 3 lengths:
    • 6.5 cm (2.6 in)
    • 9 cm (3.5 in)
    • 28 cm (11.0 in)


  • Processor & Coil: Mixture of polycarbonate and acrylonitrile-butadiene-styrol polymer
  • Earhook: Polyamide (PA)
  • Cable: PVC and TPE Evoprene
  • Biocompatible according to ISO 10993-1
  • Latex-free*


  • Compatible with all MED-EL multichannel cochlear implants
  • MAX Programming Interface
  • MAESTRO System Software 8.0 or later
  • Compatible with hearing aids of all brands and types
  • Exact bimodal synchronization with any hearing aid: Signal can be delayed up to 10 ms with the latest MAESTRO Software

Product Features

  • Frequency Range 70–9300 Hz
  • Water-resistant according to IP54 standard
  • Dual microphones
  • Extended Datalogging
  • Automatic Sound Management 3.0
  • Tamperproof design
    • Secured earhook
    • Locking battery pack
    • Choking hazard avoidance
    • Additional fixation options
    • Locking coil cable (locked to coil and control unit)
  • Link-check coil function with LED indicator
  • Four program positions
  • Continuous volume and sensitivity control with FineTuner Echo or AudioKey 2

Sound Processing Features

Front-End Processing

  • Microphone Directionality (Omni, Natural, Adaptive)
  • Automatic Volume Control with Dual-Loop AGC
  • Wind Noise Reduction
  • Ambient Noise Reduction
  • Transient Noise Reduction
  • Input Dynamic Range (IDR) of 78 dB (28–106 dB SPL)


Coding Strategies

  • FS4 (Fine Structure Processing up to 1 kHz on 4 apical channels)
  • FS4-p (Fine Structure Processing up to 1 kHz on 4 apical channels with Intelligent parallel Stimulation for even higher temporal accuracy)
  • FSP (Fine Structure Processing typically up to 350 Hz on 2 apical channels)
  • HD-CIS (High Definition CIS)
  • Biphasic or Triphasic stimulation pulses
  • Supports 250 spectral bands




  • 2.4 GHz wireless communication
  • Direct wireless audio streaming via Bluetooth Low Energy with AudioStream
  • True stereo sound quality
  • Support for bilateral usage
  • Integrated telecoil
  • Bimodal streaming possible with several brands of hearing aids



  • Dimensions: 68 x 38 x 17.5 mm
  • Weight: 35 g
  • Remote microphone
  • Hands-free phone calls
  • TV streaming
  • Music streaming
  • Direct audio input (DAI)

AudioKey 2 app

  • Remote control functionality
  • Guardian functionality
  • Extended Datalogging
  • Find My Processor
  • Send Feedback

FineTuner Echo

  • Dimension: 104 x 38 x 11 mm
  • Weight: 32g (including battery)
  • Compact remote control with bi-directional communication
  • ePaper Display
  • Test audio processor microphones
  • SONNET 2 battery status

WaterWear cover

  • Waterproof up to 4 metres depth
  • Can be used in salt, fresh, and chlorinated water

Battery Options

Zinc-Air Batteries

  • Up to 60 hours of use with a set of 2 disposable zinc-air 675 batteries

SONNET 2 Rechargeable Battery Max

  • Dimension: 32 x 14 x 7 mm
  • Processor weight with battery: 10.4 g
  • Usage time: Up to 17 hours
  • Charging duration: ~6 hours
  • Charging/discharging: >1800 cycles (80% capacity)****

SONNET 2 Rechargeable Battery Standard

  • Dimension: 22 x 14 x 7 mm
  • Processor Weight with Battery: 9.1 g
  • Usage time: Up to 10 hours
  • Charging duration: ~4 hours
  • Lifetime: >1800 charging/discharging cycles****

SONNET 2 Rechargeable Battery Micro

  • Dimension: 16 x 14 x 7 mm
  • Processor Weight with Battery: 8.1 g
  • Usage time: Up to 7 hours
  • Charging duration: ~3 hours
  • Lifetime: >1800 charging/discharging cycles****

SONNET 2 Charging Unit

  • 4 simultaneous charging slots
  • Power & charging indicator lights
  • USB powered: 5V DC, 500mA
  • USB power adapter: 100–240V AC (~50/60 Hz)

SONNET 2 Mini Battery Pack

  • Dimensions: 66 x 29 x 14 mm
  • Weight (without battery): <13g
  • Usage time:
    Up to 37 hours with 1 AAA battery or
    up to 16 hours with Rechargeable DaCapo Powerpack

Direct Wireless Streaming Cover for SONNET Series Audio Processors

AudioStream can be used as a Made for iPhone (MFi) Hearing Device and supports the Audio Streaming for Hearing Aids (ASHA) technology. MED-EL recommends keeping your device(s) updated with the latest version of the iOS or Android operating system. AudioStream is compatible with iOS version 11 or later and Android version 10 or later.


Devices Suitable for Bimodal Streaming

For bimodal streaming, you simply need an Android smartphone with the Android 12 operating system or later, a hearing aid with ASHA (Audio Streaming for Hearing Aid) technology, and an AudioStream. The below lists include devices specifically tested and confirmed by MED-EL to be suitable for bimodal streaming. Other Android devices and hearing aids with the necessary technologies may also be suitable for bimodal streaming when using AudioStream.



Google Pixel 7, Google Pixel 6, Google Pixel 5a, Google Pixel 5, Google Pixel 4a, Google Pixel 3a

Samsung Galaxy S23, Samsung Galaxy S22, Samsung Galaxy S21+,  Samsung Galaxy S21, Samsung Galaxy S20 Ultra, Samsung Galaxy Z Fold2, Samsung Galaxy S10e

Xiaomi Mi 11T Pro

OnePlus 9 Pro

Oppo Find X5, Oppo Find X3 Pro

Hearing Aids
Beltone Imagine, Beltone Amaze, Beltone Boost Ultra, Beltone Rely

Oticon More, Oticon Real, Oticon Intent

ReSound ENZO Q, ReSound LiNX Quattro, ReSound Key, ReSound One 

Signia Pure Charge&Go X, Signia Pure Charge&Go AX, Signia Pure Charge&Go IX, Signia Pure Charge&Go T IX

Starkey Livio AI, Starkey Evolve AI

Widex Moment

The above list includes devices specifically tested and confirmed by MED-EL to be compatible with AudioStream. In addition, other Android devices with Android 10 or later and both Bluetooth® Low Energy (BLE) and Audio Streaming for Hearing Aids (ASHA) technology enabled by the phone manufacturer and service carrier may also be compatible with AudioStream. Other Apple devices with iOS 11 or later and both Bluetooth® Low Energy (BLE) and Made for iPhone (MFi) technology enabled by the phone manufacturer and service carrier may also be compatible with AudioStream.

Although MED-EL aims to provide as many users as possible with seamless device compatibility, MED-EL cannot guarantee full compatibility or troubleshooting support with all devices and the information provided above should only be used for reference.

Apple®, iPad®, iPad Air®, iPad Pro®, iPhone® and iPod Touch® are trademarks of Apple Inc., registered in the U.S. and other countries. Android is a trademark of Google LLC.
The Bluetooth® word mark and logos are registered trademarks owned by the Bluetooth SIG, Inc. and any use of such marks by MED-EL is under license.