## 1 Introduction  
Sound is a mechanical vibration that propagates through elastic media, such as liquid, air, and solids. Sound can comprise varying frequencies, with the audible frequency range in air for humans commonly accepted as between 20 hertz (Hz) and 20 kHz (although this range is significantly reduced with age) [1]. Sound, across the entire spectrum, has been shown to influence organisms with traditional auditory pathways, such as humans, and organisms without auditory pathways, such as a variety of plants [2, 3]. Vibrations below and above the audible range, infrasound and ultrasound, respectively, have been shown to significantly affect the growth and development of microorganisms [4, 5, 6, 7, 8]. However, little is known about the effect of audible sound range on microbial cells [9]. Studies that have investigated audible sound effects on microbes have typically found impacts on the growth and metabolism of model microorganisms. For example, three sound stimuli (1, 5, and 15 kHz pure tones) increased the biomass yield of _Escherichia coli_ compared to a silent control, with a 5 kHz pure tone producing the largest change [10]. Similarly, another study found that three different sound stimuli (1, 5 and 10 kHz pure tones) promoted _E. coli_ growth under normal and stressed conditions, with a significant reduction in the inhibitory effect of 3% sodium chloride [11]. In our previous work with the yeast _Saccharomyces cerevisiae_, two continuous pure tones (0.1 and 10 kHz) at an intensity of ~90 dB increased growth rate during exponential phase by an average of 12% compared to silence and altered the levels of 32 metabolites [12]. Furthermore, classical Indian music was shown to increase _S. cerevisiae_ growth by ~3% compared to silence [13]. It has even been reported that the bacterium _Bacillus carbonophilus_ emits very low-intensity sound that affects the growth of neighbouring colonies, significantly increasing their colony-forming efficiency under heavy metal stress conditions [14]. Sound applied to these microorganisms by loudspeakers mimicked the growth-promoting effect of this microbial sound [15]. Similarly, _S. cerevisiae_ has been shown to produce nanomechanical motion in the range of 0.9-1.6 kHz, depending on the temperature of growth [16]. These vibrations are sufficiently strong (~10 nN) to affect the cell membrane, propagating into the surrounding media, and can be mimicked by artificial sound waves. To understand how sound affects microbes requires an understanding of the pathways, cellular changes, and other underlying mechanisms driving a microbial response. However, due to the complexity of sound, these mechanisms could be extremely diverse, and as such a well characterised model organism is required [17]. _S. cerevisiae_ is the preferred eukaryotic single cell model organism, with a well characterised protein network and metabolic response in many conditions [18; 19]. Furthermore, _S. cerevisiae_ is extensively used in industrial processes [20]. As such, _S. cerevisiae_ is the perfect organism to extend our understanding of the effect of sound on microorganisms, from the previous studies conducted in _E. coli_, to an industrially relevant eukaryotic organism. The metabolism of microorganisms is important for many industrial processes, including the production of a wide variety of food products and high-value molecules [21]. Of these processes, the production of alcoholic beverages through fermentation by _S. cerevisiae_ remains one of the largest industrial uses of microorganisms [20; 22]. In the beer industry, the fermentation of malt to ethanol is the major role of _S. cerevisiae_. However, the production of secondary metabolites by yeast, such as higher alcohols, esters, and phenols, impacts the flavour profile of beer [23]. In particular, volatile compounds provide a major proportion of the sensory profile of beer. The compounds produced are determined by the strain of yeast used, growth rate, and environmental conditions during fermentation [24; 25].