# Sounds as Properties **Nick Young** Department of Philosophy, Universita degli Studi di Milano, Milan, Italy ## Abstract Leddington has recently put forward a new version of the idea that sounds are properties. Whereas other 'property views' take material objects to be the bearers of sounds (the sound of a bell being struck is a property instantiated by the bell itself), on Leddington's view sounds are borne by the source events in which these objects are participating (the sound of a bell being struck is a property instantiated by the striking event). In this paper, I argue that the case for events as the bearers of sound properties rather than objects is, at best, ambiguous, and that there are good reasons for wanting to include objects amongst the things we hear. I put forward a new account on which sounds are temporally extended properties of objects. This approach, I argue, not only retains the advantages of Leddington's view, but also allows for the audibility of both objects and events. **Keywords:** audition, perception, properties, sounds, temporal experience ## 1 | Introduction Although thinking of sounds as properties is not a new idea, the novelty of a view recently put forward by Jason Leddington lies in its 'treating sounds as properties of events rather than objects' (2019, p. 624). According to other 'property views' (Locke, 1690/1975, II, viii, 14; Pasnau, 1999; and Kulvicki, 2008), sounds are instantiated by material objects: the sound of a bell being struck is a property instantiated by the bell itself. In contrast, on Leddington's account, Property, sounds are instantiated by the source events in which these objects are participating: it is the striking, not the bell, which bears a sound. That is, the striking bears an audible property constituted by the qualities pitch, timbre, and loudness, in a similar way to how the bell itself bears a visible colour property constituted by hue, saturation, and brightness (2019, n. 6). In this paper I give some reasons as to why we might want to resist this idea, and argue that sounds are best thought of as temporally extended properties of objects. In §1, I outline the reasons that Leddington gives as to why Property should be preferred over two other accounts of what sounds are. In §2, I argue that the case for events as the bearers of sound properties rather than objects is, at best, ambiguous, and that there are good reasons for wanting to include objects amongst the things we hear, but that it is not obvious how object-property views allow for the hearing of source events as well as their objects. In §3, I put forward a new account on which sounds are temporally extended properties of objects, and argue that this approach allows for events to be heard through the hearing of sound bearing objects. In §4, I show that this view, Shape, retains the advantages that Property has over its competitors. ## 2 | Sounds as Events or Properties In making the case for Property, Leddington compares the view to two other recent accounts of the relation between sounds and sources. On O'Callaghan's (2011) Parthood view,^1 sounds and sources are different types of event, with the former heard as a proper part of the latter: a struck bell vibrates and so disturbs the surrounding air, according to Parthood this disturbance event is the sound of the bell, and hearing it as a proper part of the striking event allows for the striking event to be heard. According to Casati et al.'s (2013) view, Identity, sounds simply are source events: we do not hear the striking of a bell via hearing the air that it disturbs, rather, hearing a striking and hearing its sound is to hear one and the same event. Casati et al. give two reasons for preferring Identity over Parthood. First, Identity seems better supported by auditory phenomenology. If sounds and sources are distinct types of audible event, then we would expect to be able to discern each within auditory experience. This does not, however, seem to be the case: when a bell is struck we seem to hear only one event, not two (2013, p. 464). Second, the idea that we only hear one type of event fits better with our ordinary ways of speaking about what we hear. Casati et al. point to the 'natural language propension to classify the objects of auditory perception in terms of events, with no reference to a supplementary category of separate sounds' (ibid.). When we speak about the things we hear, we typically refer either to source events themselves (banging, clapping, scraping), or use words to refer to sounds which are nominalisations of the verbs we use to describe source events (a bang, a clap, a scrape). Leddington agrees that these are good reasons to give up Parthood, but thinks that Property should be preferred over Identity. He argues that, like Parthood, Identity does not fit with our common sense ideas and ways of speaking about sounds. First, Identity seems to allow that sounds can be perceived through perceptual modalities other than audition: a deaf person, or someone with their fingers in their ears, can see a bell being struck, or smell onions sizzling, but if sounds are identical to sources, then it follows that they are seeing a sound in the first case, and smelling a sound in the second (2019, p. 623). Identity also gives up the idea that sounds are caused by source events. If the striking of the bell is the chime, and the frying of the onions is the sizzle, it seems that we cannot also say that the chime was produced by the striking, or that frying onions make a sizzling sound (ibid.) Property, Leddington says, avoids both of these problems. First, although a bell being struck can be seen, and onions being fried can be smelt, seeing and smelling do not allow for the perception of pitch, timbre, or loudness, and so, by identifying sounds with combinations of these audible qualities, Property keeps sounds out of reach of non-hearers. Second, drawing on work by Lewis (1986), Sanford (1985), and Ehring (2009), Leddington (2019, fn. 8) argues that we can think of property instances as a type of event which can stand in causal relations to other types of event, and that therefore we can think of sound properties of source events as being caused by those source events: the striking of the bell both causes and instantiates its sound in something like the same way we might think of the explosion of a firework causes and instantiates its greenness. ## 3 | The Bearers of Sound Even if we accept Leddington's reasons for thinking Property superior to its competitors, we might still ask why we should accept the idea that events rather than objects are the bearers of sounds. To begin, here are two reasons for wanting an account of audition which does allow for the hearing of objects. First, just as Casati et al. argue that it does not seem, experientially, as if we hear both a sound and a source neither is it phenomenologically obvious that auditory awareness of the participants of events is any less direct than awareness of their activities: I can hear how hard the striking is, but also that the object being struck is large and metallic. Second, such a position coheres with an even wider range of ordinary language statements than Property. It is just as natural to say 'I heard the bell' as it is to say 'I heard the ringing'. In earlier work, Leddington (2014) suggests that sentences such as 'I heard the bell' are 'implicitly understood as elliptically picking out an event by picking out an object involved in it' (2014, p. 330). but, arguably, a view of audition which does not add such a complication to everyday language is preferable to one that does. Against the idea that objects are heard Leddington says: 'strictly speaking, objects do not make sounds—events do. The static bell is silent; striking it elicits sound' (ibid.), and also that it is 'part of our ordinary conception of sound that objects as such are silent – and so, that sound sources proper are events' (2019, fn. 1). However, static objects being silent need not be taken as evidence that we do not hear objects at all –it could just as easily be understood as revealing that we only ever hear objects when they are doing something, similar to how we only ever see objects when they are illuminated. We might also ask whether this idea really is part of our ordinary conception of sound. The fact that various object-property views have been put forward suggests that this intuition is not shared by everyone. As well as this, it does not seem as though objects and events are as distinct from each other as the phrase 'rather than' suggests. We could interpret 'rather than' as meaning something like instead of or in place of, material objects,^2 comparable to the way that someone might claim we smell odours but not the objects which emit them (e.g., Richardson, 2013). However, it does not seem as though the objects and events that produce sound waves are entirely distinct in the way that objects and odours are. The smell of fish might linger after the fish has been removed but the bell participates in the ringing in such a way that there would be no ringing if there were no bell. We might disagree as to exactly what this participation amounts to, and there are differing views as to the relationship between objects and events,^3 but it seems difficult to deny that there is some sort of dependency relation between them. A weaker, and arguably more plausible, interpretation of Property would be to say that while objects and events cannot be distinguished, and thus that objects in some sense are heard, it is events, not their objects, which instantiate sounds. A football match might be exciting, and a banquet lavish, and while each event depends upon particulars (the players, the ball; the diners, the food etc.), these do not themselves exhibit excitingness or lavishness. Similarly, we might say that the ringing, while linked in some way with the bell, instantiates a property that the bell does not, and it is this property which should be identified as the sound. The difference between sounds, as defined on Property, and excitingness or lavishness is that sounds are sensible properties, and here it becomes more difficult to see why we should think that events but not objects are doing the instantiating. If sounds are sensible properties then we would expect them to have what we might call physical realisers. That is, that there is some physical feature of the world that they are either identical to, or depend on.^4 Consider the audible qualities pitch, timbre, and loudness which Leddington takes to be constituents of sound properties (2019, fn 6). These qualities are identical to or depend on worldly instantiations of, respectively, frequency, spectral composition, and amplitude. Exactly how these qualities relate to their physical realisers depends upon one's views about the nature of sensible properties and qualities, but whichever approach is endorsed, there will still be some sort of link between the sensible and the physical. As O'Callaghan (2007) puts it: > 'Whether audible qualities are dispositions, physical properties, primitive qualities, or projected sensory qualities, their instances depend upon the physical properties that explain the occurrence of audible quality experiences' (2007, p. 74). Now, for any normal auditory experience these physical features would be instantiated in the world three times over: by sound waves, by disturbances of the medium, and by vibrations of the object itself. Given that both sound waves and medium disturbances are distinct from source events and their objects, neither seems like a good candidate for a realiser of Property's sounds, leaving vibrations as the only remaining possibility. This does not, however, provide an unequivocal reason for thinking that sounds are properties of events but not objects: on the one hand, vibrations are temporally extended—they require time to unfold—and one might take this as a reason for thinking that they are realisers of audible qualities (and so the sounds) of events. On the other, it is objects which are doing the vibrating: if sounds depend upon some fact about an object one might take this as a good reason for thinking that it is the object which is instantiating the sound.^5 If there is no obvious reason to believe that events but not objects instantiate sounds, and there are reasons for wanting an account of audition which allows for objects to be heard, why not go with a more traditional object-property view of sound rather than Property? While the temporarily extended nature of vibrations does not provide a clear reason for thinking events bear sound properties, what I take to be the most pressing difficulty for the traditional approach does relate to the temporal character of audition: if sounds are properties of objects, how can objects and events be heard? Arguing that we hear objects but not events is unattractive for exactly the same reasons that excluding objects from what we hear is unattractive. Experientially, it seems, that we hear events just as much as objects, and saying simply that we hear objects as instantiating sound properties does not explain why auditory experiences of the same object differ depending on what is happening to that object (a bell being struck sounds different from that same bell being scraped). It would also be unfortunate if accommodating ordinary sentences such as 'I heard the bell' meant reducing sentences such as 'I heard the ringing' to ellipses. A desideratum for any object-property view, then, would be to show how hearing objects to instantiate sounds allows for the hearing of events as well. I will now try and put forward just such an account. ## 4 | Sounds as Temporally Extended Properties I said above that if sounds are properties of sources, the physical realisers of audible qualities are most plausibly the vibrations of objects. Another theory which posits a close connection between sounds and vibrations is Casati and Dokic's Located Event Theory on which 'sounds… are identical with, or at least supervene on, vibration processes in the source' (Casati et al. 2020). Where their view differs from mine is the ontological category in which they place vibrations. They go on to say: > [this] makes plain what category sounds belong to, as opposed to views that construe sounds generically as qualities. Sounds are either instantaneous events or temporally extended processes. They start and cease. They are intrinsically temporal entities. I do not deny that sounds are intrinsically temporal, but this does not force us into categorising sounds as events rather than properties. Instead, sounds can be thought of as temporally extended, sensible properties of objects. That is, as perceivable properties that require some duration of time for their instantiation. There seems no reason to deny that we can perceive such properties as it is common to think that we do not perceive the world instant by instant, but rather perceptually 'take in' a duration of about a second. As Soteriou puts it: > '… the things we perceive are perceived as filling, occupying, or having some location within, an interval of time, just as the objects we see are generally seen as filling, occupying, or having a location within a region of space' (Soteriou, 2011, p. 195; see also Phillips, 2011; Richardson, 2014). If we have a temporal field in the same way that we have a visual spatial field,^6 then it is possible that, just as the former allows for objects as bearing spatially extended sensible properties like texture or shape,^7 the latter allows for whatever we hear to be heard as bearing temporally extended properties. Indeed, I think that sound is best thought of as a property very similar to shape. At first this idea might seem bizarre; shape, like colour, does not seem to be the sort of property that audition is in the business of revealing. The trick is, however, to think of an object's sound as its shape-in-time.^8 Imagine seeing an object which has an intricate and irregular texture at one end which gradually flattens out so that its other end is completely smooth. An object's sound, I suggest, can be thought of as a fairly precise temporal analogue of this case. All a vibration is is an object taking on slightly different shapes at different instants. Consider an object which is disposed to vibrate at just one frequency: striking it will cause it to deform slightly, before springing back towards its original shape, and overshooting so as to deform in the other direction. This process of deformation and overshooting continues until all the kinetic energy provided by the strike dissipates. A bell, like almost all everyday objects, vibrates at multiple frequencies simultaneously, with the amplitude and frequency of each of these frequencies varying over the course of their existence. Striking a bell, therefore, leads to the object taking on a series of subtly different shapes over a period of time before arriving back at its original, stable configuration. This series is what I think we should identify with the sound of the bell being struck. According to this view, call it Shape, a sound is a temporally extended property of an object consisting of all the forms it takes on during the period that it vibrates. The bumpy object has just one shape, its spatial-extended rough-to-smooth texture, which we perceive in virtue of the visual spatial field; the struck bell has just one sound, its temporally extended rough-to-smooth texture, which we perceive in virtue of our temporal field. On Shape, the audible qualities are not constituents of sounds so much as sensible aspects. Our spatially bumpy object's texture might consist of features such as a row of shallow bumps with a fairly steady rate of recursion, a second row, made up of increasingly deep indentations with double the recursion rate of the first, and a third row which begins with a recursion rate three times that of the first, but becomes progressively more irregular as it continues across the surface. In virtue of the spatial field (as well as the various gestalt grouping mechanisms which structure visual experience), we are able to perceptually pick out these interwoven aspects but really they are nothing over and above certain fine-grained features of the object's shape. Similarly, according to Shape the physical realisers of pitch, timbre and loudness, are simply fine-grained aspects of an object's shape-in-time. In virtue of having a temporal field, as well as auditory system's tendency to group spectrally and temporally related frequencies together,^9 we are able to pick out various audible aspects of the object's surface. A sound's pitch, which—simplifying—depends on all its harmonics being integer multiples of its lowest, fundamental frequency, can be compared to noticeable regularities (such as ratios between recursion rates of bumps) within a texture; hearing loudness (as well as fluctuations in loudness) can be thought similar to seeing the size of the bumps and the depth of indentations. Timbre has a more complex relationship with vibrations—arguably, it is a mistake to think of it as a single audible quality—but is comparable to various 'high-level' perceivable aspects of a texture, such as its degree of regularity, and whether its bumps are sparsely distributed, or packed tightly together. How does Shape allow for event hearing? First, notice that shape-in-time explains why an object will sound different depending on its activities. Given that how a bell vibrates depends on whether it is struck or scraped,^10 we can say that it takes on a different shape-in-time depending on the type of force applied. I think that we can go further here and say that we hear source events by hearing objects' sounds. Consider how we see objects to be what they are by seeing their shape. You see the bell as a bell. Why? Because, in virtue of your spatial field, you see it as extending through space in a bell-shaped way. If the bell were melted down and moulded into a sphere, you would still, at least in some sense, be seeing the same object, but as it is no longer bell-shaped you would not see it as a bell. Some might quibble here as to whether we really are seeing the bell as a bell, this would depend upon whether one thinks that artifactual properties are represented in perceptual content (see, for example, Byrne & Siegel, 2017), but according to our common sense ideas about what we see and how we see them: we see objects to be the objects that they are, and often do so by seeing their shapes. On Shape, the same applies for audition. We hear source events to be the source events they are by hearing the sounds of their objects. You hear a striking because, in virtue of your temporal field, you hear a bell as possessing a 'having been struck' shape-is-time, and your perceptual awareness of this event is just as direct as your visual awareness of any material object. ## 5 | Plusses Preserved Finally, let us see how Shape stacks up against the three other views of sound that have been mentioned. In Section 1, we saw the two reasons for preferring Identity or Property over Parthood were that these views fit better with both auditory phenomenology and our ordinary ways of speaking about sounds. Shape retains both of these advantages: it holds that we only hear one type of thing, objects, and makes no reference to an extra category of separate sounds. Arguably, it fits better with auditory phenomenology and ordinary language by allowing objects and events (through the hearing of shape-in-time) to figure in auditory experience equally, and not reducing sentences such as 'I heard the bell' to ellipses. It also, like Property, puts sounds out of the reach of non-hearers: a deaf person can see a bell being struck, but, given that they cannot perceive the subtle ways in which the object's shape fluctuates as it vibrates, they do not perceive its sound.^11 Shape also retains the idea that sounds are caused by source events. An object takes on a particular shape-in-time depending on how it is stimulated and its physical properties. Again, we can see this through a comparison with ordinary, spatial shape. First, objects that are at least somewhat elastic, take on different shapes depending on what sort of force is applied to them: a stiff breeze will cause an empty shopping bag to inflate into one sort of shape, while placing an object inside of it will cause another; a heavy load will cause a tabletop to sag, but applying pressure from below will make it arch upwards. Likewise, striking the bell causes the object to take on a particular sound and scraping will cause it to take on another.^12 In both cases, the precise shape of the object will be determined not only by the type of force applied but by the object's mass, size, and material constitution. The same heavy object will stretch a plastic bag into a different shape than it would a paper bag, and the degree to which a table top sags under its load will depend on whether that it is made from a thin sheet of plastic, or a sturdy slab of oak. Similarly, the same firm thwack will cause a large copper bell to take on a different shape-in-time than it would a smaller one made out of porcelain. ## 6 | Conclusion According to Shape, sounds are temporally extended sensible properties of objects. Such a view retains all the advantages of Property but fits better with auditory phenomenology and ordinary language by allowing that both objects and events are heard. While claims that we hear events, or that the things we hear are temporally extended, come up frequently in philosophical treatments of audition, this work seldom engages directly with the wealth of literature on temporarily extended perception and the metaphysics of persistence. Focussing on the temporally extended nature of what we hear will, I think, help us understand the relations between sounds, objects, and events, and help determine more precisely the similarities and differences between audition and other perceptual modalities. The view outlined here can be considered a first step in this direction.^13 ## Endnotes 1. The labels Property, Parthood and Identity are taken from Leddington, 2019 2. Although the idea that events bear sound properties is novel, the idea that we hear the activities of objects rather than, or prior to, their objects can also be found in both O'Callaghan (2011, p. 399) and Casati et al. (2013, p. 3). 3. For an overview of these issues see Simons (2005). 4. Leddington does not endorse a particular account of what sensible properties are, nor does he say whether he follows Locke in thinking of sounds as 'secondary qualities'. That is, as capacities of physical features of the world to produce sensations in us, rather than 'primary qualities'—observer-independent properties of those features. I want to remain neutral here also, although on the proposal I put forward in §3 sounds might be thought more similar to primary than secondary qualities. 5. I say more about this in §3. 6. Here I assume, following Soteriou, as well as Richardson (2014), and Phillips (2011, p. 825), that, unlike the spatial field, the temporal field structures audition as well as vision. 7. In what follows I will assume that texture is nothing but an object's fine-grained shape. 8. A more natural label for what I have in mind would be 'temporal shape', but this term has already been used by Steward (1997) to mean something quite different. 9. Bregman (1994, ch.2) gives details of the sorts of grouping rules that the auditory system uses. 10. See Gaver (1993) for discussion of how different types of force affect the character of vibrations/sound waves. 11. I do not rule out the possibility that sounds could be seen by someone possessing extremely acute visual capacities, or by using some sort of sensory substitution device. Indeed if we accept that the physical realisers of sounds are vibrations then it is easy to imagine ways in which vibrations could be accessed in some perceptual but non-auditory way. There is a difference, however, between allowing that these sorts of unusual cases might be possible, and suggesting, as Casati et al. appear to, that sounds are regularly seen (felt, smelt etc.) by ordinary perceivers. Leddington makes a similar point: we can maintain the idea that hearing is the normal way of perceiving sounds, without insisting that they are the special sensibles of audition (2019, n. 4). I am grateful to an anonymous referee for pressing me on this. 12. Like Property, this idea relies on the notion that property instances can be causal relata. 13. This research was funded by the Department of Philosophy "Piero Martinetti" of the University of Milan under the Project "Departments of Excellence 2018–2022" awarded by the Ministry of Education, University and Research (MIUR) and the project "Time and Emotion" (ID-35533) of the University of Milan. Support was also received from the project "Rethinking and communicating time (CHRONOS)", PID2019-108762GB-I00 of the Spanish Ministry of Science and Innovation. I am grateful to have received extremely useful comments on the ideas presented in this paper from my colleagues at the Centre for Philosophy of Time at the University of Milan, especially Giuliano Torrengo, Davide Bordini, Dave Ingram and Cristian Mariani. Thanks also to Bence Nanay and Jason Leddington for long and fruitful discussions about sounds. Finally, thanks to an anonymous referee whose comments inspired a quite significant revision of my ideas on this topic. ## References Bregman, A. S. (1994). *Auditory scene analysis: The perceptual organization of sound*. MIT press. Byrne, A., & Siegel, S. (2017). Rich or thin. In *Current controversies in philosophy of perception* (pp. 59–80). England: Routledge. Casati, R., Di Bona, E., & Dokic, J. (2013). The Ockhamization of the event sources of sound. *Analysis*, 73(3), 462–466. Casati, R. Dokic, R. Di Bona, E. (2020). "Sounds", *Stanford encyclopedia of philosophy*. In E. N. Zalta (Ed.). https://plato.stanford.edu/archives/sum2020/entries/sounds/ Ehring, D. (2009). Causal relata. In H. Beebee, C. Hitchcock, & P. C. Menzies (Eds.), *The Oxford handbook of causation* (pp. 388–413). Oxford University Press. Gaver, W. W. (1993). What in the world do we hear?: An ecological approach to auditory event perception. *Ecological Psychology*, 5(1), 1–29. Kulvicki, J. (2008). The nature of noise. *Philosophers' Imprint*, 8, 1–16. Leddington, J. (2014). What we hear. In *Consciousness inside and out: Phenomenology, neuroscience, and the nature of experience* (pp. 321–334). Springer. Leddington, J. P. (2019). Sounds fully simplified. *Analysis*, 79(4), 621–629. Lewis, D. (1986). Causation. In *His philosophical papers* (Vol. 2, pp. 159–213). Oxford University Press. Locke, J. (1690/1975). *An essay concerning human understanding*. Clarendon Press. O'Callaghan, C. (2007). *Sounds: A philosophical theory*. Oxford University Press. O'Callaghan, C. (2011). Hearing properties, effects, or parts? *Proceedings of the Aristotelian Society*, 111(Part III), 375–405. Pasnau, R. (1999). What is sound? *The Philosophical Quarterly*, 49, 309–324. Phillips, I. (2011). Indiscriminability and experience of change. *The Philosophical Quarterly*, 61(245), 808–827. Richardson, L. (2013). Sniffing and smelling. *Philosophical Studies*, 162(2), 401–419. Richardson, L. (2014). Space, time and Molyneux's question. *Ratio*, 27(4), 483–505. Sanford, D. H. (1985). Causal relata. In E. LePore & B. McLaughlin (Eds.), *Actions and events: Perspectives on the philosophy of Donald Davidson* (pp. 282–293). Blackwell. Simons, P. (2005). Events. In M. J. Loux & D. W. Zimmerman (Eds.), *The Oxford handbook of metaphysics*. Oxford University Press on Demand. Soteriou, M. (2011). The perception of absence, space, and time. In J. Roessler, H. Lerman, & N. Eilan (Eds.), *Perception, causation, and objectivity*. Oxford University Press. Steward, H. (1997). *The ontology of mind: Events, processes, and states*. Oxford University Press.