Relation between Speech-in-Noise Threshold, Hearing Loss and Cognition from 40–69 Years of Age David R. Moore 1,2,3 *, Mark Edmondson-Jones 1,4 , Piers Dawes 5 , Heather Fortnum 1,4 , Abby McCormack 1,2,4 , Robert H. Pierzycki 1,4 , Kevin J. Munro 5,6 1 NIHR Nottingham Hearing Biomedical Research Unit, Nottingham, United Kingdom, 2 MRC Institute of Hearing Research, University Park, Nottingham, United Kingdom, 3 Cincinnati Children’s Hospital Medical Center and Department of Otolaryngology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America, 4 Otology and Hearing Group, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, United Kingdom, 5 School of Psychological Sciences, University of Manchester, Manchester, United Kingdom, 6 Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom Abstract Background: Healthy hearing depends on sensitive ears and adequate brain processing. Essential aspects of both hearing and cognition decline with advancing age, but it is largely unknown how one influences the other. The current standard measure of hearing, the pure-tone audiogram is not very cognitively demanding and does not predict well the most important yet challenging use of hearing, listening to speech in noisy environments. We analysed data from UK Biobank that asked 40–69 year olds about their hearing, and assessed their ability on tests of speech-in-noise hearing and cognition. Methods and Findings: About half a million volunteers were recruited through NHS registers. Respondents completed ‘whole-body’ testing in purpose-designed, community-based test centres across the UK. Objective hearing (spoken digit recognition in noise) and cognitive (reasoning, memory, processing speed) data were analysed using logistic and multiple regression methods. Speech hearing in noise declined exponentially with age for both sexes from about 50 years, differing from previous audiogram data that showed a more linear decline from ,40 years for men, and consistently less hearing loss for women. The decline in speech-in-noise hearing was especially dramatic among those with lower cognitive scores. Decreasing cognitive ability and increasing age were both independently associated with decreasing ability to hear speech- in-noise (0.70 and 0.89 dB, respectively) among the population studied. Men subjectively reported up to 60% higher rates of difficulty hearing than women. Workplace noise history associated with difficulty in both subjective hearing and objective speech hearing in noise. Leisure noise history was associated with subjective, but not with objective difficulty hearing. Conclusions: Older people have declining cognitive processing ability associated with reduced ability to hear speech in noise, measured by recognition of recorded spoken digits. Subjective reports of hearing difficulty generally show a higher prevalence than objective measures, suggesting that current objective methods could be extended further. Citation: Moore DR, Edmondson-Jones M, Dawes P, Fortnum H, McCormack A, et al. (2014) Relation between Speech-in-Noise Threshold, Hearing Loss and Cognition from 40–69 Years of Age. PLoS ONE 9(9): e107720. doi:10.1371/journal.pone.0107720 Editor: Joel Snyder, UNLV, United States of America Received March 12, 2014; Accepted August 21, 2014; Published September 17, 2014 Copyright: ß 2014 Moore et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: DRM was supported by the Intramural Programme of the Medical Research Council [Grant U135097130] and by Cincinnati Children’s Hospital. The Nottingham Hearing Biomedical Research Unit is funded by the National Institute for Health Research. This paper presents independent research funded in part by the National Institute for Health Research (NIHR). The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health. This research was facilitated by the NIHR Manchester Biomedical Research Centre. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. * Email: david.moore2@cchmc.org Introduction The detection of quiet tones of varying frequency, has for .70 years been the gold standard test of hearing [1]. However, the most frequent complaint expressed by people about their hearing is inability to follow speech in noisy environments [2]. Pure-tone audiograms, measures of tone detection threshold across frequency [2], and speech perception measured in the quiet [3], do not predict well the handicap produced by hearing loss. These principles were first recognized long ago [4–7], as was the finding that speech-in-noise (SiN) hearing ability decreases with age [3], even while the audiogram may remain relatively stable [4]. SiN measures that use familiar speech correlate with the average level of hearing based on the pure-tone audiogram (the ‘pure tone average’, PTA [8–10]) and may offer an alternative gold standard more relevant to everyday hearing. Despite much research, SiN hearing has until recently received little attention in large population studies and limited clinical application. However, the development of the Digit Triplets Test (DTT [11]), a measure of SiN hearing that can be administered without specialist supervi- sion and in any quiet room (go to actiononhearingloss.org.uk for a demonstration and test), enabled inclusion in UK Biobank [12,13]. UK Biobank is an internationally accessible data resource based on a very large-scale, ongoing, longitudinal study across England, Scotland and Wales of many aspects of health, starting in middle age (40–69 year olds; www.ukbiobank.ac.uk). PLOS ONE | www.plosone.org 1 September 2014 | Volume 9 | Issue 9 | e107720