A moment of truth: Widex PureSound™ goes head-to-head against other brands

A new study shows that the innovative PureSound™ program in WIDEX MOMENT™ preserves speech understanding in noise.
The study, conducted by Kuk, Ruperto, Slugocki and Korhonen of Widex/WSA, demonstrates that Widex PureSound™  is as effective as the premium products of two other leading manufacturers for managing speech understanding in noise at realistic signal-to-noise ratios (SNRs). 

What’s more, it shows that hearing aid users’ performance with the PureSound™ program is similar to that of people with normal hearing under the same realistic SNRs. 

Why conduct the study?

In addition to the traditional WIDEX Universal signal path, WIDEX MOMENT™ has a whole new ultrafast signal path and sound processing in the PureSound™ program. And i's essential that this new signal path does not compromise the effectiveness of WIDEX MOMENT™  in real life. 

Therefore, the Widex/WSA study examined whether the PureSound™ program, which operates an omnidirectional microphone, yields speech-in-noise performance that is similar to other premium digital hearing aids that include an adaptive directional microphone. The authors tested WIDEX MOMENT™ in an open-ear fitting under realistic SNR conditions. 

About the new technology

WIDEX MOMENT™ has a unique PureSound™ program that uses ZeroDelay™ technology to shorten the processing delay of the hearing aid to less than 0.5 ms across frequencies. This enhances the subjective quality of sounds processed by the hearing aid. 

Implementing such an ultrashort delay, required the new design of signal path and sound processing features. The resulting more natural perception of sounds is achieved by preserving the temporal nuances and minimising the spectral distortion from comb-filtering. 

This type of distortion typically occurs with open-ear fitting, due to the mixing of the natural sound and the delayed amplified sound.  

Less distortion with PureSound™

Figure 1 shows how the temporal characteristics of the input sound in an open-fit device are distorted much less with PureSound™ than with leading competitors’ products.
WIDEX MOMENT™ is designed to use the PureSound™ program under typical listening conditions. But in very challenging situations, the hearing aid can switch to the Universal program and use directional microphones instead.

Study procedure

The new study compared the PureSound™ program to two competitor's premium products.

The Repeat portion of the Quick Repeat-Recall Test (Quick RRT) was used to compare subjects’ speech understanding ability in noise under realistic SNRs. The Quick RTT evaluates speech-in-noise understanding for high-context (syntactical and meaningful, e.g., “keep the ice cream in the freezer”) and low-context (syntactical but meaningless, e.g., “keep the ice foods in the lemon”) sentences at SNRs of 0 , 5, 10, 15 dB and quiet.

Performance similar to normal hearing

Figure 2 shows the average repeat performance for all three hearing aids at different SNRs. The shaded regions on the plot can be used to compare the performance of the aided hearing-impaired listeners to the expected performance of normal hearing listeners. For example, if the score falls in the lightest blue area, it suggests performance similar to the top 25% of normal hearing listeners.
 
As you can see in Figure 2, the average scores of all three hearing aids are within 5% of each other at all SNRs tested. This suggests that despite the differences in features among hearing aids (and the use of an omnidirectional microphone in the PureSound™ program), the speech-in-noise performance of all three hearing aids under realistic SNRs is similar. Moreover, the average aided repeat performance of all three hearing aids puts the listeners’ performance within the average range of normal hearing listeners (the medium blue area, or between the 25th and 75th percentile).

A previous guided sound walk study also showed that users prefer the ultralow delay PureSound™ program over a standard delay program. Users described the sound as "more natural,” "clearer" and “more detailed.”

Summary

The findings of the new study, coupled with the previous guided sound walk study, show that PureSound™ and the ZeroDelay™ technology in the WIDEX MOMENT™ hearing aid optimise sound quality in daily situations – while preserving speech understanding in noise.

For further details of the methods and results and a discussion of the study, you can download the original article here.