Reducon of listening effort with binaural algorithms in hearing aids: an EEG study Axel Winneke

1, Maarten De Vos

2, Kirsten Wagener

3, Mahias Latzel

4, Peter Derleth

4, Jens Appell

1, Frank Wallhoff

1,5

1Fraunhofer IDMT, Oldenburg, Germany

2Oxford University, Oxford, UK,

3Hrzentrum, Oldenburg, Germany,

4Phonak AG, Stfa, Switzerland,

5Jade Hochschule, Oldenburg, Germany

Introduction

Back-ground

Several surveys report that many hearing aid wearers are dissatisfied when using the telephone with a hearing

aid (Kochkin 2002; 2005; 2010).

The difficulty which they face when using the phone is thought to be due to a number of factors:

lack of visual clues, reduced frequency bandwidth, lack of binaural hearing abilities, presence of (loud) back-

ground noise and difficulties coupling the phone to the hearing aid.

One approach to support the binaural hearing abilities is the use of binaural algorithms in hearing aids when us-

ing the phone by transferring the signal at the phone-ear via wireless connection to the contralateral ear. This

technology is available in Phonak hearing devices and is called DuoPhone.

Binaural presentation of the phone signal has been shown to be advantageous in several studies but this effect

is strongly dependent on the methodology of coupling the phone with the hearing aid (Kiessling et al. 2013,

Picou & Ricketts, 2011; 2013, Latzel et al. 2014).

Especially for acoustic coupling the correct positioning of the receiver is essential (Holmes and Chase 1985, Lat-

zel et al. 2001).

Subjective measures show favorable results for binaural presentation of the phone signal (with DuoPhone)

but these could not be confirmed as statistically significant in speech tests ( Nyffler 2010, Latzel et al. 2014).

Does DuoPhone reduce the listening effort by making use of presenting the phone signal bin-aurally when using EEG measurements to determine listening effort? (Winneke and Phillips 2011, Obleser et al. 2012 )

Possible Conclusion

DuoPhone is able to increase the capacity of the working memory and to reduce the cogni-tive load based on the assumption that a raised listening effort requires (neural) resources which are then missing for later cognitive processes (see shared resource hypothesis, Rabitt et al. 1968).

But as objective measures did not confirm the success of DuoPhone in the market it is interesting to look into subjective dimensions.

A study by Sarampalis et al. (2009) showed interesting results: switching a noise reduction on and off resulted in a reduction of the response timewhich is correlated with the listening effortalthough the conducted speech test did not show any differences (using a dual-task paradigm) This result confirms: listening effort is a relevant measure

The listening effort can be measured with

Subjective ratings like questionnaires (e.g. Gatehouse & Noble 2004) or scaling (e.g. Krger et a. 2015)

Single-/Dual-Task paradigms (e.g. Sarampalis et al. 2009) with determination of behavior measures

Physiological measures: Magnetic Resonance Imaging (e.g. Wild et al. 2012), Pupillometry (e.g. Zegveld et al. 2011), Skin conductance (e.g. Holube et al. 2015) and Electroencephalography (EEG) (e.g. Obleser et al. 2012)

.physiological indicators provide potential objective measures, which are correlated with the listening effort (Winneke and Phillips 2011, Obleser et al. 2012 )

.they provide objective measures without active cooperation of the subjects

Decision to use EEG Measurements, as...

References Gatehouse S, Noble W (2004) The Speech, Spatial and Qualities of Hearing Scale (SSQ) International Journal of Audiology, 43, 85-99. Holmes A & Chase N (1985) Listening ability with a telephone adapter. Hearing Instruments 36:16-17. Holube I, Haeder K, Imbery C, Heindorf R, Weber R (2015) Subjective listening effort and electro dermal activity in listening situations with reverberation and noise for normal-hearing and hearing-impaired listeners Poster at International Symposium on Auditory and Audiological Research (ISAAR), Nyborg, Denmark. Kiessling J, Kreikemeier S, Margolf-Hackl S, Nesgaard J, Thunberg Jespersen C (2013) Telefonieren im Strschall: Moderne Lsungen zum Telefonieren mit Hrsystemen im Vergleich Supplement to 16th anual meeting of DGA, Rostock. Kochkin, S (2002) MarkeTrak VI: 10-year customer satisfaction trends in the US hearing instrument market Hear Rev, 9, 1425. Kochkin, S (2005) MarkeTrak VII: Customer satisfaction with hearing aids in the digital age Hear J, 58, 3039. Kochkin S (2010) MarkeTrak VIII: Consumer satisfaction with hearing aids is slowly increasing The Hearing Journal; 63(1): 19-27. Krger M, Schulte M, Holube I (2015) Entwicklung einer adaptiven Skalierungsmethode zur Ermittlung der subjektiven Hranstrengung Supplement to 18th anual meeting of DGA, Bochum. Latzel, M, Gebhart, T, Kiessling J (2001) Benefit of a digital feedback suppression system for acoustical telephone communication Scand Audiol Suppl, 52, 6972. Latzel M (2013) Compendium 4 - Adaptive Phonak Digital (APD) , Phonak Compendium (http://www.phonakpro.com/com/b2b/en/evidence.html). Latzel M, Wolfe J, Appleton-Huber J, Anderson S (2014) Benefit of telephone solutions for children and adults Poster at the the 43rd annual scientific and technology conference of the American Auditory Society. Nyffeler M. (2010) Easier telephone conversations with both ears Phonak Field Study News. Obleser J, Wstmann,M, Hellbernd N, Wilsch A, Maess B (2012) Adverse listening conditions and memory load drive a common alpha oscillatory network The Journal of Neuroscience, 32(36), 12376-12383. Picou E, Ricketts T A (2011) Comparison of Wireless and Acoustic Hearing Aid-Based Telephone Listening Strategies Ear & Hearing; 32(2): 209-220. Picou E, Ricketts T (2013) Efficacy of Hearing-Aid Based Telephone Strategies for Listeners with Moderate-to-Severe Hearing Loss Journal of the American Academy of Audiology; 24: 59-70. Rabbitt P (1968) Channel-capacity, intelligibility and immediate memory Quarterly Journal of Experimental Psychology, 20, 241248. Wild C, Yusuf A, Wilson D, Peelle J, Davis M, Johnsrude I (2012) Effortful Listening: The Processing of Degraded Speech Depends Critically on Attention The Journal of Neuroscience 32(40):14010 14021. Winneke A, Phillips N (2011) Does audio-visual speech offer a fountain of youth for old ears? An event-related brain potential study of age differences in audiovisual speech perception Psychology and Aging 26 (2), 427-38. Zekveld A, Kramer S, Festen J (2011) Cognitive load during speech perception in noise: The influence of age, hearing loss, and cognition on the pupil response Ear Hear , 32 , 498 510 Zokoll M, Wagener K, Brand T, Buschermhle M, Kollmeier B (2012) Internationally comparable screening tests for listening in noise in several European languages: The German digit triplet test as an optimization prototype Int. J. Audiol. 51(9):697-707. Zokoll M, Hochmuth S, Warzybok A, Wagener K, Buschermhle M, Kollmeier B (2013) Speech-in-Noise Tests for Multilingual Hearing Screening and Diagnostics Am. J. Audiol. 22(1):175-178

Discussion and Take Home Message

(Subjects 7 (out of 10) experienced hearing aid users Gender: 5 male, 2 female Moderate to severe hearing loss (see figure 1) Mean age: 73,4 y (SD 3,46 y) Participants had previously taken part in the study described in

Latzel et al. (2014)

Test devices Phonak Naida Q90-SP Fitting: Adaptive Phonak Digital (Latzel, 2013), closed vent

Conditions Variation of DuoPhone and SNR Condition#1: DuoPhone OFF and low SNR: DPoff_LowSNR Condition#2: DuoPhone ON and low SNR: DPon_LowSNR Condition#3: DuoPhone OFF and high SNR: DPoff_HighSNR

SetUp Presentation of signals (65 dB SPL) via circumaural open headphones

Sennheiser HD-650 (covering hearing aids) to reduce variance of positioning phone receiver

Simulation of a landline connection using an A-law codec Presentation of noise (ISTS) with two SNR conditions:

LowSNR = individual SNR from TDT HighSNR = LowSNR + 3 dB

The binaural algorithm DuoPhone.

..improves the auditory processing: Amplitute N1

..reduces the cognitive load/listening effort: activity in alpha frequency band

Same effect is observed when increasing the SNR by 3 dB (determination of the results by Obleser et al. 2012) DuoPhone has an comparable effect to the improvement of the SNR by 3 dB!!

The EEG - measurement is a potential methodology to objectively quantify the listening effort and was shown to be more sensitive than behavioural measures.

Results Overall observation

Behavioral measures and P3 wave dont show any significant differences between the test conditions!

DPon_LowSNR DPoff_LowSNR (influence of DuoPhone) Visual observation: the topographical distribution of DPoff and DPon differ significantly

Statistical analysis: certain electrodes show statistically significant differences (p