World leading acoustic beamforming technology
Nuance hearing’s acoustic beamforming technology shows world-class performance in directional capabilities and audio focus.
In the field of “real-time” applications, this is the most effective technology in the world. Our technology is a highly effective solution for dealing with background noise and voice distractions and in use by the global hearing industry giants.
What is acoustic beamforming
Acoustic beamforming technology is a signal processing technique, capable of focusing on sounds (acoustic signals) coming from a certain direction, relative to the other directions.
Using an array of microphones, an algorithm detects from which direction each sound in the space around it comes, according to time gaps in its reception between the microphones.
The algorithm creates a gap in the volume between the sounds from the preferred direction and the background noise.
Ultra fast signal processing
Nuance hearing’s hardware and software platform – captures sounds, processes them, and plays them – at a record speed of 6.25ms
Directivity Index - DI
The reduction of the overall noise compared to the sound waves from the target direction is measured in decibels (dB), and is defined as the “direction coefficient”.
Nuance Hearing was able to develop products with a direction coefficient of 15dB, (the signal-to-noise ratio improves by a multiplier of 30 in acoustic energy).
For comparison, the world’s most advanced “real-time” products display a directional coefficient of no more than 4-5 dB.
Auto steering technology
Our unique auto steering technology automatically selects the preferred hearing direction from which the highest acoustic energy comes, up to two directions simultaneously.
This allows tracking the dominant speaker even in motion (e.g., a classroom teacher), or automatically switching between speakers in a multi-participant conversation.
The direction of listening is changed within a few milliseconds, smoothly, so that the listener does not miss even the first syllable at the beginning of the sentence.
Speech intelligibility test and SNR
For each product we develop, we perform a speech intelligibility test. We use a well known measure, known as “SNR50”, to demonstrate the effect of our technology on speech perception in noise.
SNR50 is a measure of the ratio between the signal and the noise (SNR – signal to noise ratio) allowing the listener to achieve 50% word recognition. In other words, we are changing the volume of the signal compared to the noise, until a listener can only recognize 50% words heard in noise. This point is their SNR50. These tests take place in a sound attenuating room, where listeners hear a target speech coming from the front, and background noise coming from their sides. The background noise is comprised of two competing talkers (one talker from each side). The volume of the noise is kept constant throughout the experiment, and the target signal volume is reduced adaptively to the listeners response.
Our test results
In the experiment, we are testing SNR50 in two conditions – with and without our device. For example, normal hearing adults typically show an average improvement of 8dB in SNR50 with the device. That is, if they can achieve 50% recognition of words in -4dB SNR (the noise is 4dB louder than the signal), with the device they reach the same performance level in -12dB SNR (the noise is 12dB louder than the signal). When the speech sounds are more audible in the presence of noise, it is easier for our brain to identify and recognize the spoken message (here insert a graph of SNR50 with and without).