How does the new Leox BTE SP perform when matched against its predecessor, Supremia BTE SP?
This is the exact question that we set out to answer when planning the clinical trial for Bernafon’s newest power hearing instrument, Leox BTE SP. Two key areas of interest were the new Dynamic Feedback Canceller™ and the effect of True Environment Processing™ with a power BTE.
We gathered 11 test subjects with moderate-to-profound hearing loss and an average age of 67 years. They were all experienced hearing aid users, with some already wearing the Supremia BTE SP.
We used a combination of lab tests in the clinic and field tests during which the subjects wore each pair of devices for a specified time in their daily life. Feedback and speech intelligibility were tested in the clinic with a live feedback test and the Wallenberg and Kollmeier monosyllabic rhyme test (WaKo) (Kollmeier, et. al., 2011). For the live feedback test, we wanted to simulate situations that are known to cause feedback for users: inserting the hearing aid, cupping the hand over the ear, holding the phone up to the ear, standing close to a wall, and removing the hearing aid. These situations were tested for each ear individually and with both sets of hearing aids (Leox and Supremia). The order of ears and instruments was randomized, and the testing was single-blinded as the investigator placed the instruments in the ears of the subjects so that they would not know which device they were testing. A visual analog scale (VAS) was used to rate the annoyance level of feedback, if it occurred, for each situation.
Speech was tested in three conditions: unaided, aided with Supremia, and aided with Leox, and in three noise levels: quiet, +5 SNR, and +15 SNR. The order of the condition, noise level, and the test lists were randomized, and the testing was single-blinded in the same way as the live feedback test. The WaKo speech test is performed with a touch screen. The target word and the noise (unless in quiet) is presented from the front speaker. The touchscreen offers 5 words that rhyme with the target word from which the subject must choose an answer. It’s a forced choice since the test will not proceed until they have selected a word.
Figure 1 shows an example of the screen during the WaKo speech test.
The lab testing did not show any significant differences between the two devices for either the live feedback or the speech intelligibility tests. This may not sound like exciting news, but it means that the feedback canceller is working as well as the previous model even with the extended output that Leox offers, and that it does not negatively impact speech intelligibility. In theory, the feedback canceller is designed by the engineers to not affect speech; however, this must be confirmed by testing the system on actual users and in the types of situations that they will encounter.
For the field tests, the subjects wore the Supremia hearing aids and then the Leox hearing aids each for approximately one week. This testing is also important as users are told to wear the hearing aids in their daily life and then report any unexpected behavior. To compare the performance of the two instruments, the subjects filled out a questionnaire called the Speech, Spatial, and Qualities of hearing scale 12 (SSQ 12) (Noble, et. al., 2013). This version of the SSQ asks the subjects to compare the hearing aids in 12 various listening situations on a scale from -5 to +5 with 0 meaning that there was no difference between the aids. Negative scores are in favor of Supremia while positive scores are in favor of Leox. See the detailed results in Figure 2.
Figure 2. SSQ-C answer distribution per question. Answers above the 0 line are in favor of Leox.
We were pleased to see that in all subscales (speech, spatial, and quality) Leox was rated significantly better than Supremia. Users found Leox more helpful with speech intelligibility, localization, sound quality, etc. in daily use than Supremia. True Environment Processing™ achieves its goals by making users more connected to their environment and helping them to hear speech better in quiet and noisy situations.
In the end the subjects had to choose a preferred hearing aid, and they overwhelmingly chose Leox. The main reasons for choosing Leox were based on speech intelligibility and sound quality. See the graph in Figure 3.
Figure 3. Frequency of motivation listed by possible answers and by device preference.
As seen in the graph, other preference motivation options were listening effort, which also received a high score, feedback, comfort, and battery life. For more details about the testing and the results, please read the latest Topics in Amplification from Bernafon AG entitled “Leox – Unlock the power”.
There are some aspects in which Supremia just can’t compete… extended power and wireless connectivity. The new Leox devices not only come in a BTE SP model but also a BTE UP model with a peak gain of 87 dB SPL and an MPO of 146 dB SPL (Ear simulator measures*). On top of this, an exciting addition to our power instruments is the use of 2.4 GHz Bluetooth® Low Energy for wireless connectivity. Users have reported “additional benefits” when using Bluetooth® accessories with their hearing aids (Smith and Davis, 2014, p. 773). The new Leox hearing aids let power users wirelessly connect to various devices to improve the SNR and consequently make challenging listening situations such as phone calls, listening to music, and watching TV more enjoyable.
The new Leox BTE SP | BTE UP packs a punch for power users.
References
Kollmeier B, Lenarz T, Winkler A, Zokoll MA, Sukowski H, Brand T, Wagener KC. (2011). Indication for and verification of hearing aid benefit using modern methods of speech audiometry in German. HNO, 59(10):1012-21.
Noble, W., Jensen, N. S., Naylor, G., Bhullar, N., & Akeroyd, M. A. (2013). A short form of the Speech, Spatial and Qualities of Hearing scale suitable for clinical use: The SSQ12. International Journal of Audiology, 52(6), 409–412.
Smith, P. and Davis, A. (2014). The benefits of using Bluetooth accessories with hearing aids. International Journal of Audiology, 53(10), 770-773.
*“Ear simulator” refers to a coupler according to IEC 60318-4:2010.
Applied versions: IEC 60118-0 /A1:1994, IEC 60118-1 /A1:1998, IEC 60118-7: 2005, ANSI S3.22: 2014, IEC 60118-0:2015