| 1. |
- Classon, Elisabet, et al.
(författare)
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Reading span performance in 339 Swedish 50-89 year old individuals with hearing impairment : Effects of test version and age, and relation to speech recognition in noise
- 2013
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The Swedish reading span test (Rönnberg, Lyxell, Arlinger, & Kinnefors, 1989) is often used to assess working memory capacity (WMC) in the field of cognitive hearing science. The test has proven useful as a predictor of speech recognition in noise in adverse conditions. It has been used in a wide range of experimental studies and has been translated to several languages. The purpose of this paper was to provide reference data for the Swedish reading span test (Rönnberg et al., 1989) in a large sample of adults with hearing impairment aged 50-89 years that are representative of patients seeking rehabilitation at audiological clinics. Data from finished and ongoing projects were collated and reanalyzed for this purpose. The original full version and a shortened version of the test were compared, in terms of percentage correct. In addition, performance on the full version was compared across two different age-cohorts, 50-69 year olds and 70-89 year olds. Frequency distributions and percentile scores are reported, as well as relations with demographic variables, and speech recognition in noise. Results showed that reading span performance was related to age, but not sex, with lower scores in older participants. Pure tone hearing thresholds accounted for a small but significant amount of the variance such that higher reading span scores were related to better hearing. The frequency distributions of scores did not differ across the two versions of the test, but the long version seemed to be more sensitive to age. Performance in both versions was significantly correlated with speech recognition in noise. Regression analyses however showed that reading span explained additional variance in speech in noise recognition, after the effects of age and pure tone hearing thresholds were accounted for, only in the 50-69 year olds. These findings are discussed in relation to age-related differences in the ability to recruit cognitive resources in the service of speech communication.
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| 2. |
- Lunner, Thomas, et al.
(författare)
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Immediate effects of signal processing on memory systems
- 2011
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Traditionally, hearing instrument signal processing schemes are evaluated where the speech recognition tests in noise are most sensitive, i.e. around 50 percent correct. However, such testing typically leads to ecologically unrealistic negative signal-to-noise ratios. Therefore, memory performance has been suggested as a more ecologically valid outcome measure in conditions with interfering background noises, and where participants perform closer to 100 percent correct. In a recent study by Sarampalis et al. (2009) they used an Ephraim-Mallah noise reduction algorithm and found beneficial effects for normal hearing participants on memory function. However, such memory effects have not been shown for hearing impaired participants. The current study on hearing-impaired subjects evaluated ‘aggressive’ ideal binary masking (IBM, see Wang, et al., 2009), as a proof-of-concept not only for improving speech comprehension but also for its potential effects of masking on memory systems. Furthermore, binary masks estimated from directional microphones (Boldt et al., 2008) were used as a realistic version of binary mask processing. Results show significant main effects of noise type and noise reduction. Noise reduction techniques improved the memory performance in the four-talker babble background, while no such improvement was observed in the steady-state noise background. Participants with higher reading span scores performed significantly better in the memory task, but only in the four-talker babble background.The study demonstrates the binary-masking noise reduction technique helps freeing up cognitive resources and hence enhances memory task performance in the four-talker babble background for hearing-impaired listeners with high reading span performance. The findings suggest that there is a cognitive challenge for the hearing aid industry to improve signal processing options for individuals to improve immediate perception and encoding into memory.
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| 3. |
- Ng, Hoi Ning Elaine
(författare)
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Cognition in Hearing Aid Users : Memory for Everyday Speech
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis investigated the importance of cognition for speech understanding in experienced and new hearing aid users. The aims were 1) to develop a cognitive test (Sentence-final Word Identification and Recall, or SWIR test) to measure the effects of a noise reduction algorithm on processing of highly intelligible speech (everyday sentences); 2) to investigate, using the SWIR test, whether hearing aid signal processing would affect memory for heard speech in experienced hearing aid users; 3) to test whether the effects of signal processing on the ability to recall speech would interact with background noise and individual differences in working memory capacity; 4) to explore the potential clinical application of the SWIR test; and 5) to examine the relationship between cognition and speech recognition in noise in new users over the first six months of hearing aid use. Results showed that, for experienced users, noise reduction freed up cognitive resources and alleviated the negative impact of noise on memory when speech stimuli were presented in a background of speech babble spoken in the listener’s native language. The possible underlying mechanisms are that noise reduction facilitates auditory stream segregation between target and irrelevant speech and reduces the attention captured by the linguistic information in irrelevant speech. The effects of noise reduction and SWIR performance were modulated by individual differences in working memory capacity. SWIR performance was related to the self-reported outcome of hearing aid use. For new users, working memory capacity played a more important role in speech recognition in noise before acclimatization to hearing aid amplification than after six months. This thesis demonstrates for the first time that hearing aid signal processing can significantly improve the ability of individuals with hearing impairment to recall highly intelligible speech stimuli presented in babble noise. It also adds to the literature showing the key role of working memory capacity in listening with hearing aids, especially for new users. By virtue of its relation to subjective measures of hearing aid outcome, the SWIR test can potentially be used as a tool in assessing hearing aid outcome.
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| 4. |
- Ng, Hoi Ning, Elaine, et al.
(författare)
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Dynamic relation between working memory capacity and speech recognition in noise during the first six months of hearing aid use
- 2014
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Ingår i: Trends in Hearing. - : Sage Publications. - 2331-2165. ; 18, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- The present study aimed to investigate the changing relationship between aided speech recognition and cognitive function during the first six months of hearing aid use. Twentyseven first-time hearing aid users with symmetrical mild to moderate sensorineural hearing loss were recruited. Aided speech recognition thresholds in noise (SRTs) were obtained in the hearing aid fitting session as well as at three and six months post-fitting. Cognitive abilities were assessed using a reading span test, which is a measure of working memory capacity, and a cognitive test battery. Results showed a significant correlation between reading span and SRT during the hearing aid fitting session. This relation was significantly weakened over the first six months of hearing aid use. Multiple regression analysis showed that reading span was the main predictor of SRT when hearing aids were first fitted, but that pure-tone average hearing threshold (PTA) was the main predictor six months later. This indicates that working memory capacity plays a more important role in speech recognition in noise before than after six months of use. We argue that new hearing aid users engage working memory capacity to recognize unfamiliar processed speech signals but that as familiarization proceeds, engagement of working memory capacity is reduced.
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| 5. |
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| 6. |
- Ng, Hoi Ning, Elaine, et al.
(författare)
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Effects of noise and working memory capacity on memory processing of speech for hearing-aid users
- 2013
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Ingår i: International Journal of Audiology. - : Informa Healthcare. - 1499-2027 .- 1708-8186. ; 52:7, s. 433-441
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: It has been shown that noise reduction algorithms can reduce the negative effects of noise on memory processing in persons with normal hearing. The objective of the present study was to investigate whether a similar effect can be obtained for persons with hearing impairment and whether such an effect is dependent on individual differences in working memory capacity.Design: A sentence-final word identification and recall (SWIR) test was conducted in two noise backgrounds with and without noise reduction as well as in quiet. Working memory capacity was measured using a reading span (RS) test.Study sample: Twenty-six experienced hearing-aid users with moderate to moderately severe sensorineural hearing loss.Results: Noise impaired recall performance. Competing speech disrupted memory performance more than speech-shaped noise. For late list items the disruptive effect of the competing speech background was virtually cancelled out by noise reduction for persons with high working memory capacity.Conclusions: Noise reduction can reduce the adverse effect of noise on memory for speech for persons with good working memory capacity. We argue that the mechanism behind this is faster word identification that enhances encoding into working memory.
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| 7. |
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| 9. |
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| 10. |
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| 11. |
- Ng, Hoi Ning, Elaine, et al.
(författare)
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Noise reduction can enhance memory for heard sentences
- 2011
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- It has been demonstrated that the benefit of signal processing intended for hearingaids is not limited to improvement in speech perception. Sarampalis et al.(2009) showed that the Ephraim-Malah noise reduction algorithm improvedcognitive performance and reduced listening effort for people with normal hearing.However, similar effects for hearing-impaired listeners have not been reported.The present study examines the effect of noise reduction in hearing aidson memory processing of speech perceived in stationary noise and competingspeech background. Twenty-six experienced hearing aid users with symmetricalsensorineural hearing loss were tested. A dual task paradigm, which consists ofa perceptual speech recognition task and a free recall memory task, was used tomeasure the cognitive outcomes with the use of binary time-frequency maskingnoise reduction technique (Wang et al., 2009). Working memory capacity wasmeasured using a reading span test. Results showed that free recall performancein the competing speech background improved with noise reduction in listenerswith better working memory capacity. No such improvement was found in thestationary noise. Listeners with better working memory also performed better inthe stationary noise than in the competing speech background. No effect of backgroundnoises or noise reduction was observed in listeners with limited workingmemory capacity. The study demonstrates that binary masking noise reductiontechnique enhances memory performance in competing speech background forpersons with good working memory capacity. In other words, working memorycapacity also predicts benefit of noise reduction signal processing.
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| 12. |
- Ng, Hoi Ning, Elaine, et al.
(författare)
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Relationships between self-report and cognitive measures of hearing aid outcome
- 2013
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Ingår i: Speech, Language and Hearing. - : Maney Publishing. - 2050-571X .- 2050-5728. ; 16:4, s. 197-207
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Tidskriftsartikel (refereegranskat)abstract
- This present study examined the relationship between cognitive measures and self-report hearing aid outcome. A sentence-final word identification and recall (SWIR) test was used to investigate how hearing aid use may relate to experienced explicit cognitive processing. A visually based cognitive test battery was also administered. To measure self-report hearing aid outcome, the International Outcome Inventory – Hearing Aids (IOI-HA) and the Speech, Spatial and Qualities of Hearing Scale (SSQ) were employed. Twenty-six experienced hearing aid users (mean age of 59 years) with symmetrical moderate-tomoderately severe sensorineural hearing loss were recruited. Free recall performance in the SWIR test correlated negatively with item 3 of IOI-HA, which measures residual difficulty in adverse listening situations. Cognitive abilities related to verbal information processing were correlated positively with selfreported hearing aid use and overall success. The present study showed that reported residual difficulty with hearing aid may relate to experienced explicit processing in difficult listening conditions, such that individuals with better cognitive capacity tended to report more remaining difficulty in challenging listening situations. The possibility of using cognitive measures to predict hearing aid outcome in real life should be explored in future research.
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| 13. |
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| 14. |
- Rudner, Mary, et al.
(författare)
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Cognitive spare capacity as a measure of listening effort
- 2011
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Ingår i: Journal of Hearing Science. - : Instytut Narzadow Zmyslow. - 2083-389X .- 2084-3127. ; 1:2, s. EA47-49
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Tidskriftsartikel (refereegranskat)abstract
- There has been a recent interest in listening effort as a factor to be taken into account in the audiological clinic. However, the term “listening effort” is poorly determined and needs to be defined before it can be used as a clinical or research tool. One way of understanding listening effort is in terms of the cognitive resources expended during listening. Cognitive capacity is finite and thus if cognitive capacity is used up during the act of listening to speech there will be fewer cognitive resources left to process the content of the message conveyed. We have introduced the term Cognitive Spare Capacity (CSC) to refer to residual cognitive capacity once successful listening has taken place. This extended abstract described the work we have carried out to date on measures of CSC for research and clinical use. In the course of this work we have developed tests to assess the role of memory load, executive function and audiovisual integration in CSC under challenging conditions. When these tests are fully developed, our aim is that they should allow objective individual assessment of listening effort in cognitive terms. Results to date indicate that under challenging conditions, CSC is an arena for executive processing of temporarily stored information; it is related to individual working memory capacity and can be enhanced by hearing aid signal processing.
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| 15. |
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| 16. |
- Wong, Lena L. N., et al.
(författare)
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Characterization of speech understanding in various types of noise
- 2012
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Ingår i: Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 0001-4966 .- 1520-8524. ; 132:4, s. 2642-2651
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Tidskriftsartikel (refereegranskat)abstract
- This study examined (1) the effects of noise on speech understanding and (2) whether performance in real-life noises could be predicted based on performance in steady-state speech-spectrum-shaped noise. The noise conditions included a steady-state speech-spectrum-shaped noise and six types of real-life noise. Thirty normal-hearing adults were tested using sentence materials from the Cantonese Hearing In Noise Test (CHINT). To achieve the first aim, the performance–intensity function slopes in these noise conditions were estimated and compared. Variations in performance–intensity function slopes were attributed to differences in the amount of amplitude fluctuations and the presence of competing background speech. How well the data obtained in real-life noises fit the performance–intensity functions obtained in steady-state speech-spectrum-shaped noises was examined for the second aim of the study. Four out of six types of noise yielded performance–intensity function slopes similar to that in steady-state speech-spectrum-shaped noise. After accounting for individual differences in sentence reception threshold (SRT) and the offset between the signal-to-noise ratio for 50% intelligibility across different types of noise, performance in steady-state speech-spectrum-shaped noise was found to predict well the performance in most of the real-life noise conditions.
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