With the dawn of the digital hearing aid in the 1990s came the artificial sound experience that's produced when the direct sound that travels through the vent and around the ear tip meets the delayed, digitally processed sound at the eardrum. This is called the comb-filter effect, and it results in an artificial, distorted sound experience.
Did you know?
The comb-filter effect is most pronounced with open and vented ear tips, where direct sound can go straight to the eardrum, where it mixes with the delayed hearing aid sound. Because open and vented ear tips are most popular among those with mild-to-moderate hearing loss, the comb-filter effect will be stronger for them - and they are more likely to notice it too.
Widex has now introduced a new hearing aid platform that's designed to overcome the comb-filter effect and the artificial sound experience that it produces. The hearing aid and platform are called WIDEX MOMENT™, the technology is called ZeroDelay™, and the most natural, delay-free sound experience is called PureSound™.
The question is, how do the shorter delay and the resulting absence of comb-filtering translate into listener benefits?
In a new guided sound walk study, 21 participants reported on their experience with the PureSound program compared with a program with standard hearing aid delay in a range of sound scenarios.
All participants were guided to different locations with varying sound scenarios for which they could indicate their preferred program.
Thirteen of the participants had mild-to-moderate hearing loss, and eight participants had normal hearing. The participants with hearing loss were a mix of new and experienced users.
A clear preference for PureSound for overall sound quality
In the study, 85% of the group with hearing loss preferred PureSound overall after the guided walk. This shows that the PureSound program has superior sound quality for the target group of new and experienced users with mild-to-moderate hearing loss.
Overall preference for PureSound vs. standard delay.
But the researchers also found it interesting that the group with normal hearing had 100% preference for PureSound, since this indicates that lower delay is perceived as more natural sound.
Throughout the walk, the participants were guided through inside and outside scenarios, including traffic noise, quiet sounds, speech, own voice, noisy surroundings and specific brief and broadband sounds.
In all 20 individual sound scenarios, the majority of participants preferred PureSound. The researchers also found that the preference for PureSound was approximately on the same level for most sound categories, ranging between 70% and 84% - except for traffic noise, which was at 100% preference for PureSound.
PureSound is "more natural"
The participants who preferred PureSound for overall sound quality indicated that they mainly preferred PureSound because it included "less noise", sounded "more natural", and was "clearer" and "more nuanced/detailed".
The reasons for preferring PureSound in individual sound scenarios echo the same themes of "less noise" and "more natural", while other prominent reasons included "pleasant", "clearer", and "less tunnel/seashell sound".
Still, some participants found the standard delay to be more "more natural" than PureSound. Interestingly, these participants were mainly experienced hearing aid users who are used to listening with standard delay - and are probably more likely to recognize it and expect it as part of the listening experience.
Standard delay still relevant for users with severe hearing loss
The study concludes that the ultralow delay with PureSound was the preferred choice for a large majority of participants across situations. But the researchers also note that PureSound is most suitable for those with mild-to-moderate hearing loss, because these users are both more likely to wear open or vented fittings and to be disturbed by the comb-filter effect.
In contrast, people who have a more severe hearing loss are less likely to be disturbed by the comb-filter effect and might benefit more from the Universal program - Widex's standard delay program - which allows more gain.
To serve all users, both PureSound and Universal are programs included in the WIDEX MOMENT™ hearing aids.
What is ZeroDelay™ Technology and PureSound™?
Learn more about ZeroDelay and PureSound here.