
What does “up to 10.2 dB SNR improvement with Spheric Speech Clarity” really mean?
Learn how Phonak used realistic testing setups and background noise stimuli to measure SNR improvements that reflect meaningful benefits for your clients.
Do you ever find it challenging to make sense of signal-to-noise ratio (SNR) improvement claims from hearing aid manufacturers?
For instance, when you read that Audéo Sphere Infinio with Spheric Speech Clarity provides up to 10.2 dB SNR improvement, do you wonder how it compares to similar claims?
SNR improvements are often used by hearing aid manufacturers to convey the benefit of a feature or hearing aid, yet the lack of standardized measurement protocols makes it difficult to compare devices objectively. Simply put, because each manufacturer uses a unique study setup, direct comparisons of SNR claims are not possible.
This blog explores two ways Phonak’s study protocols set us apart, ensuring that our SNR improvement claims are reliable and relevant to real-world use.
1. Realistic testing setup
The loudspeaker setup used during testing is crucial for assessing a hearing aid’s SNR performance in real-world conditions. In comparing study setups, Phonak’s approach (Fig. 1A) stands out for its practical design. Phonak uses a 12-loudspeaker array, with speech and noise co-located at 0 degrees and noise coming from all directions. This setup closely mimics the complexity of real-world environments, providing a more accurate representation of hearing aid performance.
In contrast, other manufacturers often use a simplified setup (Fig. 1B) with two noise sources placed at 120 and 240 degrees. These positions align with where directional microphones perform best, resulting in an overestimation of SNR benefits achieved by directional microphones.
This figure illustrates how the Phonak study setup, with noise sources all around, provides a challenging yet realistic evaluation. In contrast, the competitor setup is less realistic and overestimates directional microphone performance.

Why It Matters:
Real-world environments involve noise from all directions, not just from behind. Phonak’s setup ensures the SNR benefit reflects actual listening challenges, giving users meaningful advantages in everyday life.
Demonstrating the impact
To illustrate the difference, we measured the SNR benefit of Phonak’s UltraZoom feature using the two setups in Figure 1. The results (Figure 2) show that with noise sources only at 120 and 240 degrees (Fig. 1B), UltraZoom achieved a higher SNR. However, in the realistic 12-loudspeaker setup (Fig. 1A), the SNR benefit was lower but more reflective of real-world conditions.

2. Realistic background noise stimuli
Background noise is another key factor in evaluating hearing aid performance. Many conventional noise reduction algorithms handle static noises (e.g., vacuum cleaners) well but struggle with complex environments like cafés or dinner parties.
Phonak’s Spheric Speech Clarity feature, powered by a deep neural network trained on over 22 million sound samples, excels in reducing complex background noise. To benchmark its performance, Phonak used realistic noise scenes from the publicly available ARTE database, including cafés, dinner parties, and food courts.
In contrast, other manufacturers often rely on static noise sources, which are less representative of real-world social settings.
Why It Matters:
Real-life noise is complex and dynamic, unlike the static noise used in many tests. Phonak’s choice of realistic noise scenes ensure SNR improvements reflect real-world challenges, delivering meaningful benefits in everyday environments.
Demonstrating the impact
When tested with static noise, Spheric Speech Clarity and conventional noise cancelling show similar SNR improvement. However, in a realistic listening environment, Spheric Speech Clarity maintains its SNR improvement, whereas conventional noise cancelling loses 50% of its effectiveness.

The impact on everyday life
Phonak‘s commitment to realistic testing means that we have technical measures that underpin clinical study results, confirming the exceptional speech understanding benefit of Audéo Sphere Infinio in complex, noisy environments. By using a 12-loudspeaker setup and realistic noise scenes to simulate everyday situations, Phonak is confident that it is delivering reliable SNR improvements that enhance communication in the real-world listening environments of your clients.
A comparison of SNR improvements across brands shows that Phonak outperforms competitors in realistic listening scenarios, providing significant benefits for those with hearing loss.
Summary
When comparing SNR claims, it’s essential to consider:
- The testing setup: Does it reflect real-world conditions?
- The noise stimuli: Are they realistic and representative of everyday environments?
Phonak’s approach combines rigorous testing with real-world relevance, ensuring that SNR improvements like the 10.2 dB achieved by Spheric Speech Clarity are truly meaningful for your clients.
To learn more, visit Phonak.com/evidence to read the Phonak Insight.
Co-authors
Stefan Raufer, Audiological Researcher at Sonova

Stefan joined Sonova in 2021 and is developing audiological concepts for new hearing aid features. Together with other teams, Stefan brings latest technology to our products, making sure that new technologies translate to user benefits. Stefan holds a PhD in speech and hearing sciences from Harvard University.
Michael Preuss, Audiology Manager at Phonak HQ

Michael joined Phonak HQ as an Audiology Manager in 2020. Benefiting from his lecturing background at the Academy of Hearing Acoustics in Lübeck and living with hearing loss, Michael delivers comprehensive expert training sessions and provides audiological input during product development. Michael studied Hearing Acoustics at the University of Applied Sciences in Lübeck, Germany.
Shin-Shin Hobi, Senior Product Manager for Audiological Performance at Phonak HQ

Shin-Shin joined Phonak HQ in 2006 and has worked on various projects as an Audiology manager. In her current role as Senior Product manager for Audiological Performance, she ensures end user and hearing care professional needs are taken into account during product development of audiological features. Originally from Australia, Shin-Shin earned her Audiology qualifications from University of Melbourne. She gained wide clinical experience in private practice, in Perth, before making the move to Switzerland.