| 1. |
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| 2. |
- Keidser, Gitte, et al.
(författare)
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The Quest for Ecological Validity in Hearing Science: What It Is, Why It Matters, and How to Advance It
- 2020
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Ingår i: Ear and Hearing. - : LIPPINCOTT WILLIAMS & WILKINS. - 0196-0202 .- 1538-4667. ; 41, s. 5S-19S
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Tidskriftsartikel (refereegranskat)abstract
- Ecological validity is a relatively new concept in hearing science. It has been cited as relevant with increasing frequency in publications over the past 20 years, but without any formal conceptual basis or clear motive. The sixth Eriksholm Workshop was convened to develop a deeper understanding of the concept for the purpose of applying it in hearing research in a consistent and productive manner. Inspired by relevant debate within the field of psychology, and taking into account the World Health Organizations International Classification of Functioning, Disability, and Health framework, the attendees at the workshop reached a consensus on the following definition: "In hearing science, ecological validity refers to the degree to which research findings reflect real-life hearing-related function, activity, or participation." Four broad purposes for striving for greater ecological validity in hearing research were determined: A (Understanding) better understanding the role of hearing in everyday life; B (Development) supporting the development of improved procedures and interventions; C (Assessment) facilitating improved methods for assessing and predicting ability to accomplish real-world tasks; and D (Integration and Individualization) enabling more integrated and individualized care. Discussions considered the effects of variables and phenomena commonly present in hearing-related research on the level of ecological validity of outcomes, supported by examples from a few selected outcome domains and for different types of studies. Illustrated with examples, potential strategies were offered for promoting a high level of ecological validity in a study and for how to evaluate the level of ecological validity of a study. Areas in particular that could benefit from more research to advance ecological validity in hearing science include: (1) understanding the processes of hearing and communication in everyday listening situations, and specifically the factors that make listening difficult in everyday situations; (2) developing new test paradigms that include more than one person (e.g., to encompass the interactive nature of everyday communication) and that are integrative of other factors that interact with hearing in real-life function; (3) integrating new and emerging technologies (e.g., virtual reality) with established test methods; and (4) identifying the key variables and phenomena affecting the level of ecological validity to develop verifiable ways to increase ecological validity and derive a set of benchmarks to strive for.
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| 3. |
- Leijon, Arne, et al.
(författare)
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Bayesian analysis of Ecological Momentary Assessment (EMA) data collected in adults before and after hearing rehabilitation
- 2023
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Ingår i: Frontiers in Digital Health. - : Frontiers Media SA. - 2673-253X. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a new Bayesian method for analyzing Ecological Momentary Assessment (EMA) data and applies this method in a re-analysis of data from a previous EMA study. The analysis method has been implemented as a freely available Python package EmaCalc, RRID:SCR 022943. The analysis model can use EMA input data including nominal categories in one or more situation dimensions, and ordinal ratings of several perceptual attributes. The analysis uses a variant of ordinal regression to estimate the statistical relation between these variables. The Bayesian method has no requirements related to the number of participants or the number of assessments by each participant. Instead, the method automatically includes measures of the statistical credibility of all analysis results, for the given amount of data. For the previously collected EMA data, the analysis results demonstrate how the new tool can handle heavily skewed, scarce, and clustered data that were collected on ordinal scales, and present results on interval scales. The new method revealed results for the population mean that were similar to those obtained in the previous analysis by an advanced regression model. The Bayesian approach automatically estimated the inter-individual variability in the population, based on the study sample, and could show some statistically credible intervention results also for an unseen random individual in the population. Such results may be interesting, for example, if the EMA methodology is used by a hearing-aid manufacturer in a study to predict the success of a new signal-processing method among future potential customers.
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| 4. |
- Leijon, Arne, et al.
(författare)
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Bayesian analysis of paired-comparison sound quality ratings
- 2019
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Ingår i: Journal of the Acoustical Society of America. - : ACOUSTICAL SOC AMER AMER INST PHYSICS. - 0001-4966 .- 1520-8524. ; 146:5, s. 3174-3183
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a method to analyze paired-comparison data including either binary or graded ordinal responses, with or without ties. The proposed method can use either of two classical choice models: (1) Thurstone case V, which assumes a Gaussian distribution of the sensory variables underlying listener decisions, or (2) the Bradley-Terry-Luce (BTL) model, which assumes a logistic distribution. The analysis method was validated using simulated paired-comparison experiments with known distributions of the sound-quality parameters in the simulated population from which "participants" were generated at random. The validation indicated that the Thurstone and BTL models give similar results close to the true values. The estimated credibility of a quality difference was slightly higher with the BTL model. The analysis results showed dramatically better precision when the response data included graded ordinal judgments instead of binary responses. Allowing tied responses also tended to improve precision. The method was also applied to data from a real evaluation of hearing-aid programs. The analysis revealed clinically interesting results with high statistical credibility, although the amount of test data was limited.
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| 5. |
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| 6. |
- Smeds, Karolina, et al.
(författare)
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Comparison of predictive measures of speech recognition after noise reduction processing
- 2014
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Ingår i: Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 0001-4966 .- 1520-8524. ; 136:3, s. 1363-1374
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Tidskriftsartikel (refereegranskat)abstract
- A number of measures were evaluated with regard to their ability to predict the speech-recognition benefit of single-channel noise reduction (NR) processing. Three NR algorithms and a reference condition were used in the evaluation. Twenty listeners with impaired hearing and ten listeners with normal hearing participated in a blinded laboratory study. An adaptive speech test was used. The speech test produces results in terms of signal-to-noise ratios that correspond to equal speech recognition performance (in this case 80% correct) with and without the NR algorithms. This facilitates a direct comparison between predicted and experimentally measured effects of noise reduction algorithms on speech recognition. The experimental results were used to evaluate nine different predictive measures, one in two variants. The best predictions were found with the Coherence Speech Intelligibility Index (CSII) [Kates and Arehart (2005), J. Acoust. Soc. Am. 117(4), 2224-2237]. In general, measures using correlation between the clean speech and the processed noisy speech, as well as other measures that are based on short-time analysis of speech and noise, seemed most promising.
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| 7. |
- Smeds, Karolina, et al.
(författare)
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Hörapparatutprovning
- 2000
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Bok (övrigt vetenskapligt/konstnärligt)
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| 8. |
- Smeds, Karolina
(författare)
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Is normal or less than normal overall loudness preferred by first-time hearing aid users?
- 2004
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Ingår i: Ear and Hearing. - 0196-0202 .- 1538-4667. ; 25:2, s. 159-172
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Most prescriptive methods for nonlinear, wide dynamic range compression (WDRC) hearing aids are based on the assumption that a hearing-impaired listener should perceive amplified sounds at the same overall loudness as would a normal-hearing listener without amplification. However, some previous research on linear amplification has indicated that subjects prefer less overall gain than prescribed by the most commonly used prescriptive method for linear hearing aids, NAIL-R, a method that gives close to normal overall loudness for a mid-level input. The current study aims at comparing two prescriptive methods for WDRC hearing aids. The methods differ in the overall loudness they aim to give the hearing aid user. One method, called NormLoudn, is based on a generic method that prescribes gain.so that the overall loudness is restored to normal. Another method, called LessLoudn, is based on a hearing aid specific prescription, and gives the hearing aid user less than normal overall loudness. Do first-time hearing aid users prefer the method that restores overall loudness to normal or the method that gives less than normal overall loudness? Design: Twenty-one first-time hearing aid users with typical hearing losses for this group of clients participated in a crossover blinded field study where the two fitting methods were compared using a multi-programmable hearing aid, Danalogic 163D. Preference in the field was evaluated using interview, questionnaire, and diary. The field test was accompanied by laboratory tests, which included paired comparison judgments of preference and loudness and a speech recognition test. Loudness calculations were also used when interpreting the results, and a theoretical comparison with other prescriptive methods for WDRC hearing aids was made. Results: After necessary adjustments, the measured gain for the two methods was similar in gain-frequency shape, but NormLoudn gave more overall gain than LessLoudn. Generally, NormLoudn fittings led to calculated overall loudness that was close to normal, whereas LessLoudn fittings, in median, led to 3-7 phon less than normal calculated overall loudness according to the loudness model used. During the interview performed after the field test, 19 out of the 21 subjects stated that they preferred LessLoudn. Also the questionnaire and the diary showed a clear preference for LessLoudn in all types of listening situations. Paired comparisons of preference in the laboratory supported the findings in the field. LessLoudn was preferred to NormLoudn in all tested situations, except for soft speech in very soft noise where there was no significant preference for either method. Speech recognition scores were similar for the two fittings. The difference in calculated loudness was clearly distinguishable to the subjects and seemed to govern their preferences. Conclusions: LessLoudn, which gave less than normal overall loudness according to the loudness model used, was preferred both in the field and in the laboratory tests. Speech recognition scores were similar for both methods. A comparison between the measured gain for NormLoudn and the gain prescribed by CAMEQ, NAL-NL1, and DSL[i/o], suggests that all three prescriptive procedures (DSL[i/o] in particular) would probably overestimate the required gain for subjects without hearing aid experience and with mild to moderate hearing loss. When providing these clients with hearing aids, it seems important to include a careful adjustment of the overall gain to avoid overamplification if the prescription used aims at restoring overall loudness to normal according to the loudness model used here.
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| 9. |
- Smeds, Karolina, 1965-
(författare)
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Less is more? Loudness aspects of prescriptive methods for nonlinear hearing aids
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In Sweden, about 10% of the adult population experienceshearing problems that cause them difficulties in everydaycommunication, and approximately 60 000 people are providedwith hearing aids each year. Despite the fact that modernhearing aids can facilitate speech communication in a widerange of listening environments, many hearing-aid users aredissatisfied with their hearing aids. It is likely that theclinical methods used for individual fitting of the hearingaids are not optimal. The current study investigates prescriptive methods fornonlinear, wide dynamic range compression (WDRC) hearinginstruments. The goal is to draw general conclusions about thepreferences of hearing aid users. Therefore, the prescriptionsare evaluated using well-established models of loudness andspeech intelligibility. Current methods differed considerably in prescribed gain.Evaluations in a laboratory test, with 20 hearing-impairedlisteners, showed that these differences led to largedifferences in perceived and calculated loudness, but only tominor differences in measured and predicted speech recognitionscores. The difference in loudness was explored in a studywhere 21 first-time hearing-aid users compared twoprescriptions. One method led to normal and the other toless-than-normal overall calculated loudness (according to theloudness model of Moore and Glasberg (1997)). The prescriptionthat led to less-than-normal overall loudness was clearlypreferred in field and in laboratory tests. Preferred overall loudness was then quantified.Hearing-impaired participants with mild to moderate hearingloss preferred considerably less-than-normal overall calculatedloudness in both eld and laboratory tests. There were nosignificant differences between inexperienced and experiencedhearing aid users. Normal-hearing participants, on the otherhand, preferred close-to-normal overall calculated loudness. Inaddition, a potential problem with the loudness model wasencountered: despite the fact that the hearing-impairedlisteners were provided with less than normal overallcalculated loudness, they rated loudness higher than thenormal-hearing listeners. The results refute the most commonly adopted rationale forprescriptive methods for WDRC hearing aids - that overallloudness should be restored to normal. Hearing-impairedlisteners with mild to moderate hearing loss preferredconsiderably less than normal overall loudness. This should betaken into account when deriving new prescriptive methods, andwhen providing clients with hearing aids. Key words:hearing impairment, hearing aid, nonlinear,WDRC, hearing aid experience, prescription, loudness, loudnessmodel, speech intelligibility, preference.
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| 10. |
- Smeds, Karolina, 1965-, et al.
(författare)
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Loudness and hearing loss
- 2011
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Ingår i: Loudness. - New York, NY : Springer-Verlag New York. ; , s. 223-259
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- A hearing loss affects many aspects of sound perception. The study of loudness in relation to hearing loss is scientifically important and interesting for several reasons. It is clinically interesting to understand the physiological reasons for the abnormal loudness perception that is common in people with hearing losses. Knowledge about individual loudness perception is central for the habilitation/ rehabilitation of people with impaired hearing. Hearing aids are designed and individually adjusted to compensate, as much as possible, for abnormal loudness perception.General knowledge about loudness perception can be gained by studying the effects of hearing loss on loudness perception.
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| 11. |
- Smeds, Karolina, et al.
(författare)
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Preferred overall loudness. I : Sound field presentation in the laboratory
- 2006
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Ingår i: International Journal of Audiology. - : Informa UK Limited. - 1499-2027 .- 1708-8186. ; 45:1, s. 2-11
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Tidskriftsartikel (refereegranskat)abstract
- This study questions the basic assumption that prescriptive methods for nonlinear, wide dynamic range compression (WDRC) hearing aids should restore overall loudness to normal. Fifteen normal-hearing listeners and twenty-four hearing-impaired listeners (with mild to moderate hearing loss, twelve with and twelve without hearing aid experience) participated in laboratory tests. The participants first watched and listened to video sequences and rated how loud and how interesting the situations were. For the hearing-impaired participants, gain was applied according to the NAL-NL1 prescription. Despite the fact that the NAL-NL1 prescription led to less than normal overall calculated loudness, according to the loudness model of Moore and Glasberg (1997), the hearing-impaired participants rated loudness higher than the normal-hearing participants. The participants then adjusted a volume control to preferred overall loudness. Both normal-hearing and hearing-impaired participants preferred less than normal overall calculated loudness. The results from the two groups of hearing-impaired listeners did not differ significantly.
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| 12. |
- Smeds, Karolina, et al.
(författare)
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Preferred overall loudness. II : Listening through hearing aids in field and laboratory tests
- 2006
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Ingår i: International Journal of Audiology. - : Informa UK Limited. - 1499-2027 .- 1708-8186. ; 45:1, s. 12-25
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Tidskriftsartikel (refereegranskat)abstract
- In a laboratory study, we found that normal-hearing and hearing-impaired listeners preferred less than normal overall calculated loudness (according to a loudness model of Moore & Glasberg, 1997). The current study verified those results using a research hearing aid. Fifteen hearing-impaired and eight normal-hearing participants used the hearing aid in the Field and adjusted a volume control to give preferred loudness. The hearing aid logged the preferred volume control setting and the calculated loudness at that setting. The hearing-impaired participants preferred, in median, loudness levels of -14 phon re normal for input levels from 50 to 89 dB SPL. The normal-hearing participants preferred close to normal overall loudness. In subsequent laboratory tests, using the same hearing aid, both hearing-impaired and normal-hearing listeners preferred less than normal overall calculated loudness, and larger reductions for higher input levels. In summary, the hearing-impaired listeners preferred less than normal overall calculated loudness, whereas the results for the normal-hearing listeners were inconclusive.
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| 13. |
- Witte, Erik, 1979-, et al.
(författare)
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Test-retest reliability of the urban outdoor situated phoneme (SiP) test
- 2023
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Ingår i: International Journal of Audiology. - : Routledge. - 1499-2027 .- 1708-8186.
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To introduce the urban outdoor version of the Situated Phoneme (SiP) test and investigate its test-retest reliability.DESIGN: Phonemic discrimination scores in matched-spectrum real-world (MSRW) maskers from an urban outdoor environment were measured using a three-alternative forced choice test paradigm at different phoneme-to-noise ratios (PNR). Each measurement was repeated twice. Test-retest scores for the full 84-trial SiP-test, as well as for four types of contrasting phonemes, were analysed and compared to critical difference scores based on binomial confidence intervals.STUDY SAMPLE: Seventy-two adult native speakers of Swedish (26-83 years) with symmetric hearing threshold levels ranging from normal hearing to severe sensorineural hearing loss.RESULTS: Test-retest scores did not differ significantly for the whole test, or for the subtests analysed. A lower amount of test-retest score difference than expected exceeded the bounds of the corresponding critical difference intervals.CONCLUSIONS: The urban outdoor SiP-test has high test-retest reliability. This information can help audiologists to interpret test scores attained with the urban outdoor SiP-test.
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| 14. |
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| 15. |
- Witte, Erik, 1979-
(författare)
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The development of the Situated Phoneme (SiP) test : A Swedish test of phonemic discrimination in noise for adultpeople with hearing loss
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the current thesis, a Swedish phoneme-level speech-audiometric test in natural background noise was developed. The test is called the Situated Phoneme (SiP) test. In the first study, different types of word metrics thought to influence lexical access were developed and calculated for more than 800 000 phonetically transcribed Swedish words, which were then assembled in a database called the AFC-list. In the second study, groups of monosyllabic AFC-list words with minimal phonemic contrast were selected as linguistic stimuli for the SiP-test, using a method by which the influence of word frequency, neighborhood density, phonotactic probability and orthographic transparency was controlled. All test words were recorded to sound files, of which the accuracy was validated in a listening experiment with 28 normal-hearing adult native speakers of Swedish. In the third study, a method was developed by which realistic masker sounds, spectrally matched to each set of test phonemes in the SiP-test material, were generated for the SiP-test based on a database of urban outdoor sound events. In the fourth study, the validity of six statistical methods for significance testing of observed score differences applicable to the SiP-test were investigated. Analyses were based both on computer simulated test sessions and on SiP-test sessions with human participants. In the latter, the SiP-test speech material was presented against the urban outdoor masker sounds at different difficulty levels to 74 people with normal hearing to severe hearing loss in a listening experiment using a multiple-alternative forced choice paradigm. Based on the results, a computational prediction model for the SiP test was developed, by which the underlying success probability of specific SiP-test trials could be estimated. In turn, this enabled the use of significance-test methods based on the Poisson’s binomial distribution, resulting in improved significance-test validity. In addition, the human SiP-test results were analyzed in terms of test-retest reliability, learning effects, content-, construct- and criterion validity within the remains of the thesis.
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| 16. |
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