Earth is a Noisy Planet. Human activity means that from megacities to oceans, most places are infected with noise and tranquility is disappearing. This was starkly illustrated during the Covid-19 pandemic lockdowns when transport and industry largely stopped, and we glimpsed what a better-sounding future might be. Noise is a health problem for one in five European citizens. At high levels it causes hearing loss. At moderate levels it creates chronic stress, annoyance, sleep disturbance and heart disease. Noise makes it harder to communicate, harming learning in schools and increasing withdrawal of older people from social situations. The 2023 House of Lord's Science and Technology Committee report called noise a "neglected pollutant" and recommended more research to reduce harms. Noise also increases mortality in marine and terrestrial wildlife. The CDT will go beyond noise control to research how to engineer positive sounds. From using sound to improve the accessibility of products, through to enhancing cultural events that boost well-being, there are many ways of creating a better aural future. The CDT focuses on the user need of businesses, society and government to create a more Sustainable Sound Future. In EPSRC's Tomorrow's Engineering Research Challenges, the sound of drones and environmental noise are highlighted as needing innovative solutions. This CDT will not only cover this challenge, but will also contribute to seven out of eight Tomorrow's Engineering Research Challenges, because noise and vibration cuts across many sectors such as transport, energy, environment, construction and manufacturing. Through the CDT, we will address recruitment issues faced by the UK's £4.6 billion acoustics industry. Our partners tell us they struggle to find doctoral-level graduates in acoustics. Cohort training will empower our CDT graduates with an unprecedented depth and breadth of knowledge. This is needed because of the complexity of the challenge, from re-engineering machines, systems and buildings, through to understanding how sound affects the health and well-being of humans and other animals. Current PhD training in acoustics is too piecemeal to tackle a problem that cuts across sectors, regulators and society. The CDT will create a unique cohort of future research leaders and innovators, with the ability to create a step-change in how sound is tackled working across disciplines. This CDT brings together four powerhouses in acoustics: the Universities of Salford, Bristol, Sheffield and Southampton; along with industrial partners, regulatory bodies, public and third sector. This provides CDT students with access to an extraordinary range of laboratories and breadth of expertise for their training. This includes domain and application knowledge across many disciplines; state-of-the-art simulation, measurement and auralisation capabilities; datasets and case studies, and routes to impact. The CDT builds on EPSRC's UK Acoustics Network that has over 1,700 members including 500+ early career researchers. Challenging interdisciplinary research projects and cohort-based training will develop the much-needed postgraduates. A mixture of week-long residentials, group project and online activities are planned. These will develop technical skills for acoustics (simulation, measurement, machine learning, psychoacoustics, etc. and key skills for research (project planning, entrepreneurship, public engagement, policy influencing, responsible innovation, etc.). Partner placements will play an important role in ensuring the cohort learns about context and how to create impact. The learning outcomes of the training have been co-created between academics and partners, to ensure CDT graduates have the skills, knowledge and understanding to create a more sustainable sound future for all.

The acoustics industry contributes £4.6 billion to the UK's economy annually, employing more than 16,000 people, each generating over £65,000 in gross value added across over 750 companies nationwide. The productivity of acoustics industry is similar to that of other enabling technologies, for example the UK photonics industry (£62k per employee in 2014). Innovation through research in acoustics is a key to its industry success. The UK's acoustics industry and research feeds into many major global markets, including the $10 billion market for sound insulation materials in construction, $7.6 billion ultrasound equipment market and $31 billion market for voice recognition. This is before the vital role of acoustics in automotive, aerospace, marine and defence is taken into consideration, or that of the major UK industries that leverage acoustics expertise, or the indirect environmental and societal value of acoustics is considered. All the four Grand Challenges identified in the 2017 UK Industrial Strategy require acoustics innovation. The Industrial Strategy Challenge Fund (ISCF, https://www.ukri.org/innovation/industrial-strategychallenge-fund/) focuses on areas all of which need support from acoustics as an enabling technology. The future of acoustics research in the UK depends on its ability to contribute to the Four Grand Challenges. Numerous examples are emerging to demonstrate the central role of acoustics in addressing the four Grand Challenges and particularly through more focused research. The acoustics-related research base in the UK is internationally competitive, but it is important to continue to link this research directly to the four Grand Challenges. In this process, the role of UK Acoustics Network (UKAN) is very important. The Network unites over 870 members organised in 15 Special Interest Groups (www.acoustics.ac.uk) who represent industry, academia and various non-academic organisations which success relies on the quality of acoustics related research in the UK. UKAN was funded by the EPSRC as a standard Network grant with the explicit aim of pulling together the formerly disparate and disjoint acoustics community in the UK, across both industry and academia. UKAN has been remarkably successful. Its success is manifested in the large number of its members, numerous network events it has run since its inception in November 2017 and contribution it has made to the acoustics research community. Unfortunately, UKAN has not been in the position to fund new, pilot adventurous or translational projects nor has it any funding support for on-going research or knowledge transfer (KT) activities. The purpose of UKAN+ is to move beyond UKAN, create strategic connections between acoustics challenges and the Grand Challenges and to tackle these challenges through pilot studies leading in turn to full-scale grant proposals and systematic research and KT projects involving a wider acoustics community. There is a great opportunity for the future of the UK's acoustics related research to move on beyond this point, build upon the assembled critical mass and explore the trans-disciplinary work initiated by UKAN. Therefore, this proposal is for UKAN+ to take this community to the next stage, connect this Network more widely in the UK and internationally to contribute through coordinated research to the solution of Grand Challenges set by the government. UKAN+ will develop a new roadmap for acoustics research in the UK related to Grand Challenges, award exploratory (pilot) cross-disciplinary research projects to the wider community to support adventure research and knowledge transfer activities agreed in the roadmap and support the development of develop full-scale bids to the government research funding bodies which are aligned with the Grand Challenges. UKAN+ will also set up a National Centre or Coordination of Acoustics Research, achieve full sustainability and support best Equality, Diversity and Inclusion practices.