Since the personal computer, we have lived a more digital existence than ever before, thanks to the accelerating pace of new innovations such as the internet, smartphones, social media, and virtual meetings. Recent events, however, have reminded us that what distinguishes humans is that we are highly social creatures, and that tangible, in-person interactions are essential and among the most pleasurable aspects of human existence.

 

Conversation is essential to our social interactions, whether it's an intimate one-on-one conversation with a loved one or sharing stories with a group of friends. It is critical that human ears have this unique ability to assist us in these situations. Our ear anatomy collects and focuses high frequency sound energy from sources in front and to the sides, which is where the vast majority of speech comes from. This, in conjunction with in-the-ear (ITE) hearing aids with microphones placed inside the ear rather than on top, can contribute to improved localisation ability as well as speech-in-noise intelligibility (1).

 

While various hearing aid types consider the microphone location effect (MLE) for acoustic performance, this is typically an averaged MLE that does not account for anatomical differences between one person's ears and another's. This is where ITEs and Unitron's advanced EarMatch modelling process come into play.

 

EarMatch is an automatic process that compensates for individual differences in external ear geometries to optimise the directional performance of Insera ITE hearing aids. This happens in three steps:

 

Characterise - From the impression's taken at Liverpool Hearing Centre, 3D models of the individual's ears is created. EarMatch analyses a wide range of anatomical parameters using 1,600 data points based on this model.

 

Recognise - Unitron's recognition algorithm analyses each ear's distinct features before searching a comparative database for the closest match among 250 distinct models.

Recognise - Unitron's recognition algorithm analyses each ear's distinct features before searching  comparative database for the closest match among 250 distinct models.

Customise - Based on that match, the modelling process then customises the beamformer's calibration to create a directional response optimised for the individual's ear.

 

The beamformer is optimised in this process to restore the natural head related transfer function (HRTF) at the eardrum. When compared to regular ITEs without EarMatch, an Insera B designed with EarMatch has up to 1 dB higher Articulation Index-Directivity Index (AI-DI). The AI-DI score is a measure of directivity that is weighted toward the frequencies most important for speech recognition. Dillion (2) estimates that a 1 dB increase in AI-DI should result in a 10% increase in sentence-based speech understanding.

 

Insera hearing aids powered by the Blu platform leverage the natural acoustic advantages of the pinna, while Insera B-312 with EarMatch optimizes directional performance for each client. They can further adjust the application of Dynamic Noise Reduction to suit their individual preferences for those challenging environments with real-time adjustments via the Remote Plus app, right in the moments they are needed. All this means the Made For All Insera B-312 paired with the Remote Plus app offers Unitron’s most personalized hearing aid ever.

 

References

Orton JF, Preves DA. Localization ability as a function of hearing aid microphone placement. Hearing Instruments. 1979;30(1):18-21.

Dillon, H. (2012). Hearing Aids (2nd ed.). New York: Thieme.