GN Hear & Now

RESOUND EXPERT

ReSound's Audiological claims

ReSound has a long history of pioneering features and amplification strategies which mimic the complex function of the ear.  We do this in order to provide hearing aid wearers with the most natural listening experience which results in ReSound being independently rated as having the best sound quality1.

The ability to recognise speech while maintaining a sense of your surroundings without undue interference from background noise requires intelligent and advanced hearing solutions.

With the introduction of ReSound LiNX 3DTM, hearing aid wearers have the ability to move even more effortlessly between different environments with greater speech recognition and listening comfort.  This is achieved through ReSound having the most accurate environmental classifier on the market, and ReSound’s new premium directional steering strategy, Binaural Directionality III.

ReSound LiNX 3D is 50% better at identifying speech in noise

Speech recognition in noise is one of the most challenging situations for hearing aid wearers and in order for hearing aids to perform well in this environment features such as directional pattern and noise reduction must be set optimally.  All manufacturers use some form of classifier to identify the listening environment, in order to adapt the features and amplification strategy to provide maximal hearing benefit.  ReSound’s environmental classifier utilises front and rear speech and noise detectors and also analyses the input level, frequency content, spectral balance and temporal properties of the incoming sound to help identify the acoustic environment. 

We measured how accurately environmental classifiers can identify speech in noise environments, comparing ReSound’s LiNX 3D with premium hearing aids from five competitors. The various hearing aids were placed in a test box and exposed to a conversation between a male and female speaker in four different noisy environments. All hearing aids were then connected to the relevant fitting software and the data logs were reviewed.

The percentage of hours each hearing aid spent in its ‘speech in noise’ setting was reviewed and the results varied greatly. ReSound LiNX 3D had the greatest accuracy at 98%. There was a vast difference between the performance of ReSound LiNX 3D compared with the least accurate competitor hearing aid which only classified 42% of hours as ‘speech in noise’.  

Consequently, we can state that when compared with other premium devices, ReSound LiNX 3D is up to 50% better at detecting speech in noise.  

Your clients can hear 80% more of the sounds around them

We know that directional microphones are required in order to provide improved speech understanding in noise. The following conditions also need to be met:  

    • The signal of interest needs to be spatially separated from the noise source
    • The signal of interest needs to be located within the directional beam and be within at least 2 metres of the listener
    • As directional microphones have forward facing beams, the listener needs to face what they want to hear

      If such conditions are met, the benefits of directional microphones can be easily realised. Of course, we know that in the real-world, this is not always achievable.  A 2011 study by Cord et al.2 found that hearing aid wearers judged the signal of interest to come from a direction other than the front more than 30% of the time in real world environments.

      ReSound has considered the advantages and disadvantages of directionality, leading to the development of Binaural Directionality III which has been incorporated into LiNX 3D. Research and testing show directional benefit in a number of situations.

      Audibility for ‘off-axis’ speech (i.e. speech coming from the back or side) was compared between ReSound LiNX 3D’s Binaural Directionality III and two premium competitor hearing aids which use binaural beamforming technology. Listeners had to correctly identify a target speech signal and were not pre-informed as to which direction the speech would arrive from. The competing noise was a combination of single talkers arriving from two directions as well as masking noise arriving from three directions, and subjects were unable to turn towards the signal of interest, so you can imagine this is not an easy task.  With ReSound LiNX 3D, listeners were able to correctly identify the off-axis target speech presented from the side and back at SNRs up to 19dB lower than with the competitor hearing aids.

      This correlates to ReSound LiNX 3D wearers hearing up to 80% more surrounding sounds while still providing superior speech recognition in noise.

      Your clients can understand 40% more speech in noise

      The test described above also included a condition where the target speech arrived from the front.  In this condition, the directional benefit for ReSound LiNX 3D was not significantly different from Hearing Aid B and was slightly less than that from Hearing Aid A. Bear in mind that in over 30% of real life situations the signal of interest does not arrive from the front.  Collapsing this result with the result from the conditions where the target speech arrived from the back or the side, ReSound LiNX 3D has an overall advantage of 8.9dB for speech arriving from any direction.  Because of the difficulty of the speech test, a conservative estimate of speech understanding improvement of 5% per dB was used. This equates to ReSound LiNX 3D having 40% - 45% greater accuracy for understanding speech from any direction in a noisy environment when compared with competitors’ premium hearing aids featuring binaural beamforming.

      To conclude, with ReSound LiNX 3D is 50% better at identifying speech in noise, and wearers are able to hear 80% more sounds around them and understand 40% more speech in noisy environments. 

      ReSound continues to provide individuals with the most natural listening experience possible with the best sound quality. As ReSound LiNX 3D allows the user to engage in everyday listening situations more easily, we really are highlighting one of our key beliefs that with ReSound LiNX 3D you can HEAR MORE THAN YOU EVER THOUGHT POSSIBLE.

      Angela Soor
      ReSound, Area Manager NSW/ACT

       

      References:

        1. Sjölander L & Groth J (2014). Independent study identified Surround Sound by ReSound as top-rated.  ReSound White Paper.
        2. Cord MT, Surr RK, Walden BE & Ditterberner A (2011). Ear asymmetries and asymmetric directional microphone hearing aid fittings.  American Journal of Audiology 20: 111-122.