An Update on Verification & Evaluation of Enhanced SoundRecover

Agenda A recap on why high frequency audibility is necessary. Extended bandwidth or frequency lowering? Fitting and verifying a frequency lowering device: Step 1: Conventional PMM verification. Step 2: Advanced PMM verification. Step 3: High frequency speech testing. Application with adults. 11/11/2018

A recap of why frequency lowering is necessary. 11/11/2018

SoundRecover - Candidacy SoundRecover for all degrees of hearing loss, audiometric configurations 10 20 30 40 50 60 70 80 90 100 110 120 Now! We Know that all audiometric configurations can profit from SoundRecover. This is shown with introducing SoundRecover in all our new Products. Now a SoundRecover solution is available for all audiometric configurations, ages and needs. Intensity (dB) 125 250 500 1 2 3 4 6 8 Frequency (Hz)

Are high frequency sounds important for speech and language development? Stelmachowicz et al(2000, 2001, 2002, 2004): Children with moderate to moderately severe SNHL need a wider bandwidth for optimal speech recognition. Young children with moderate to moderately severe SNHL show delays in fricative production (Moeller et al., 2007; Stelmachowicz et al, 2004). Children with access to high-frequency information (i.e., >4K Hz) demonstrate better short-term word learning (Pittman, 2008). 5

Candidacy – why is frequency lowering needed? Boothroyd et al 1992(5) that hearing instrument bandwidth should extend to at least 10kHz.

Stelmachowicz et al (2001): Effect of stimulus Stelmachowicz et al (2001): Effect of stimulus bandwidth on the perception of /s/ in normal and hearing impaired adults and children(6)n the perception of /s/ in normal and hearing impaired adults and children(6) Four groups of 20 subjects. Adults ranged from 19-43 years. Children ranged from 5-8 years. Adults: acquired hearing loss. Children: pre-lingually hearing impaired. Engage audience in dialog With this degree of hearing loss, how well do you expect children to perform when fit with conventional hearing instruments? In a recent study, Kortekaas and Stelmachowicz (2000) investigated the effects of low-pass filtering on the perception of /s/ in normal-hearing adults and 5– 10 year-old-children. Results revealed that, in noise, children required a wider signal bandwidth than adults in order to perceive /s/ correctly. These developmental differences for normal-hearing children raise the issue of whether restriction of the stimulus bandwidth for children with hearing loss may have a negative impact on speech and language development. Turner and Cummings (1999) are probably the most straightforward way to assess the effects of stimulus bandwidth on perception. Thus, this general approach was used to evaluate the effects of high frequency audibility on the perception of /s/ in normal-hearing and hearing-impaired adults and children (Stelmachowicz, Pittman, Hoover and Lewis 2001). Four groups of 20 subjects were included in order to assess the effects of both hearing loss and age. The figure above shows the mean audiograms for these four groups. The adults ranged from 19–43 years of age and the children ranged from 5–8 years of age. All of the children were prelingually hearing impaired and the adults had hearing losses that were acquired later in life. A Sound Foundation Through Early Amplification: The Importance of High-Frequency Amplification for Young Children Patricia G. Stelmachowicz, Ph.D., Boys Town National Research Hospital

The challenge of making high-frequency speech cues audible Stelmachowicz et al (2001): Effect of stimulus bandwidth on the perception of /s/ in normal and hearing impaired adults and children(2)

Limited band-width of speech through conventional hearing instruments Male talker Female talker The figure shows the one-third–octave band spectra of /s/. The solid line shows the male /s/ with a first primary peak at 5000 Hz. The dashed and dotted lines show the spectra of the child and female /s/, which continues to rise until 9 kHz. The child /s/ has more mid-frequency energy. Conventional hearing aids provide little usable gain/output when frequencies exceed roughly 4 – 6 kHz. Given the limited bandwidth of current hearing aids, it is likely that the peak energy of a female and child /s/ may not always be audible to hearing-aid users. As a result, children with hearing loss may hear the plural form of words reasonably well when spoken by a man but inconsistently or not at all when spoken by a woman or another child. As a result, they may experience inconsistent exposure to /s/ across different talkers, situations, and contexts. Audibility of all speech sounds is vital for speech and language development. Scientific literature suggests the importance of providing high frequency amplification for children to: Support optimal language development Enable clear own speech production Hearing Loss in Children and Adults: Audiometric Configuration, Asymmetry, and Progression. A. L. Pittman; P. G. Stelmachowicz Ear and Hearing:Volume 24(3)June 2003pp 198-205 The sound samples were taken with permission from Pat Stelmachowicz, Hearing Aid Research Lab at Boys Town National Research Hospital Stelmachowicz, et al. 2001(6) 9 9

Extended bandwidth of frequency lowering? 11/11/2018

Wide-band amplification? 10 20 30 40 50 60 70 80 90 100 110 120 125 250 500 1k 2k 4k 8k The most important argument is the bandwidth of the HI receiver. Normal HI are working between 0,1 and 6 kHz. The graph shows this for us and another pediatric micro competitor, Oticon Vigo. Even though they say they have an extended high frequency bandwidth up to 8 kHz, they reach peak gain at 4kHz. After this the gain drops a lot so the information in this area get lost, because the receiver is not able to provide enough gain in this area. SoundRecover compresses and shifts the high frequency (up to 10kHz) into an area of lower frequencies and expands audibility that way. Here you see gain curves for Nios micro and Oticon Vigo (competitor 1). They meet tagrgets very well up to 6kHz. After this the gain begins to drop. If we extrapolate the DSL target curve it will show that at the high frequency targets cannot be met by the hearing instruments and thus high frequency information is lost. All instruments were set to measurement settings without any fine tuning and as you can see, they are all essentially the same. Receiver and coupler limitations mean inability to meet fitting targets in high frequencies Microphones and receivers in all HIs from all companies come from just 2 or 3 manufacturers. And it is just a simple fact that receiver limitations do not permit sufficient gain of very high frequencies to provide meaningful or useful gain in this frequency region for anything but a very mild hearing loss. >>These are real ear measurements based on the audiogram shown using DSL pediatric targets. The competitor hearing instrument is Vigo, Oticons pediatric instrument.

SoundRecover or Extended Bandwidth? Now we will see how SoundRecover actually extends the perceptual bandwidth. Let me first explain these rather odd-looking curves. Here, we are using a special signal that lets us focus on the high frequencies only. This signal, available with the Verifit, takes a broadband speech signal and reduces the gain above 1000 Hz by 30 dB except for a one-third octave band section centred on 6.3 kHz (presented again here at 65dB). Doing so creates a “notch” that allows us to view the audibility provided for a signal roughly the same as the male phoneme /s/. So you can just ignore the low and mid frequencies and focus on this section representing /s/. We have the same audiogram and the same 3 hearing instruments as used on the previous slide with the exact same program settings. All are fine-tuned for maximum gain in the highest frequencies. Again, the green curve is the Phonak instrument which, as you can see, even without SoundRecover still provides the best response. But even so, this achieves only borderline audiblity. Clearly, neither competitive extended bandwidth instrument does any better. The blue curve shows the effect of turning ON SoundRecover. With SoundRecover, the /s/ signal is now clearly audible. Ultimately, this shows us that even with extended bandwidth, only SoundRecover can actually extend the real perceptual bandwidth, providing audibility simply not possible otherwise. In other words, Extended bandwidth you can measure, SoundRecover you can actually hear. These benefits are available for all your clients, regardless of budget. /s/ /s/ Phonak Nios S H2O SoundRecover ON SoundRecover OFF Competitor A premium HI with extended bandwidth Competitor B

Enhanced SoundRecover

SoundRecover for Paediatrics New SoundRecover Settings for DSL 5 (Child): Enhanced SoundRecover prescription settings for moderate-moderately severe high-frequency hearing loss: improved audibility/less fine-tuning. Stronger implementation of SoundRecover for steeply sloping audiometric configurations: improved audibility/less fine-tuning. SoundRecover automatically deactivated in cases of ‘normal’ (< 20dBHL) high-frequency thresholds.

Why is high frequency audibility important? Without the ability to detect, distinguish and recognise minimal speech differences the ability to accurately interpret a message is hindered. Strong correlation between speech understanding and patient satisfaction. Linked to patient satisfaction: If a patient cannot understand with their hearing aids, they will feel that their hearing aids are not providing enough benefit and will be dissatisfied with them. How test results can be used: Validate frequency lowering settings regardless of manufacturer (compression/modulation/transposition) Measure hearing aid benefit of high frequencies Help counsel on appropriate communication expectations Until now we could not validate frequency lowering in hearing aids Now validate settings and make automatic recommended fitting software changes to settings based on results using Target 3.2 software (Phonak Instruments only) Language independent, to be discussed further when we discussed the sub-tests later

Fitting and verification of a frequency lowering device: 11/11/2018

‘Best Fit’ Settings Externally Validated ‘The speech recognition benefit observed for the majority of child participants in the study produced a consistent fitting pattern that can be used to accurately predict frequency compression parameters from the end user’s audiogram’ – Susan Scollie, University of Western Ontario

Step 1: Conventional PMM verification 11/11/2018

Verifying SoundRecover

Why is it needed?

Step 1: Verify to Multi-Level Targets

Step 1: Verify to Multi-Level Targets

Step 1: Verify MPO

Step 1: Verify MPO

Step 2: Advanced PMM verification 11/11/2018

Use of Frequency Specific Speech Bands A new verification option available with the Audioscan Verifit ® Useful when evaluating the effects of SoundRecover, audibility of speech sounds and potential confusions Illustration of the Audioscan Verifit® Frequency Lowering Test

Verifying SoundRecover Is /s/ audible? SoundRecover Off

Verifying SoundRecover Is /s/ audible? SoundRecover On – default setting

Verifying SoundRecover Is /s/ audible? SoundRecover ‘stronger’ +1

Verify No Confusion With /sh/

SR Stronger: +1

SR Stronger: +2

SR Stronger: +3

Application with adults 11/11/2018

A Clinical Study: Advantages of a non-linear frequency algorithm in noise – Bohnert et al 2010 11 experienced hearing instrument users (‘high-quality’ DSP) Severe/profound hearing loss OLSA adaptive speech-in-noise test Subjective questionnaires Only SoundRecover active (no noise cancelation or directional mic.) 7/11 demonstrated improved SRT’s 8/11 demonstrated improved levels of satisfaction towards SoundRecover devices. Question relationship between ‘dead-regions’ and likely benefit from SoundRecover.

OLSA Results 5/11: Statistically significant improvement with SR. 3/11: No significant difference between either condition. 3/11: Poorer performance with SR P: O.O5

Satisfaction Rating

Conclusion ‘We conclude that non-linear frequency compression is a valuable option for hearing impaired patients. Especially those with marked high-frequency hearing loss’

Summary Audibility of high-frequency speech only possible with frequency lowering. Verification/evaluation of functional outcomes is key. SII is theoretical and should not be relied on as a single measure: Does not differentiate between different speech types. Children different to adults. Key Opinion Leaders in Paediatrics recommend the use of frequency lowering as default fitting strategy provided above steps are routinely taken. A significant evidence base now exists to support this… Audibility dependent on other factors: Not all speech received in quiet at 1m. Noise. Individual SNR requirements.

www.phonakpro.com/evidence:

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