3.1 No interruption

A sustained drone with a long decay, if left in its solo state, without interference or encroachment by any other sound, exhibits continuity without interruption. This example of no interruption (Figure 1 shows a graphic illustration, while Figure 2 shows an audio region illustration of this example) exists as a control that provides a point of comparison with the other interruptions featured in the typology. See Movie 1.

Sounds without interruption are those that present their full intended duration without interference from another external sound. These sounds come to an end naturally in their own time.

Figure 1.

Graphic illustration – No interruption.

Figure 2.

Audio region illustration – No interruption.

3.2 Unsuccessful interruption

An unsuccessful interruption (Figure 3) is one that perceptually fails to disturb the continuity of the pre-existing sound. For example, in Figure 4 a drone decay sound begins; however, a second sound, in this instance, an impact, occurs part way through the drone sound. Despite the occurrence of the impact, the drone sound continues without pause or breakage and remains unaffected, so the interruption is deemed unsuccessful. The word ‘unsuccessful’ denotes the impact’s inability to alter or interfere with the pre-existing drone, but this is still recognised as an ‘attempt’ to interrupt.Footnote ²

Figure 3.

Graphic illustration – Unsuccessful interruption.

Figure 4.

Audio region illustration – Unsuccessful interruption.

The term ‘unsuccessful interruption’ is derived from its application within communication studies and correlates with a range of instances, for example, within a conversation, a person may try to speak over another but fails to take the floor, so is thus deemed unsuccessful. Unsuccessful interruptions can vary in their intention and are not always floor-taking attempts. These have different roles in conversations such as ‘back channel behaviours’ (Yngve Reference Yngve1970), and ‘accompaniment signals’ (Kendon Reference Kendon1967), which generally account for interjectory remarks (such as ‘uhm’, ‘yeah’, ‘that’s true’ and ‘exactly’). Ferguson notes that the function of these interjectory remarks seem to be ‘the very opposite of effecting a change in speaker, since they appear to ensure that the speaker who is holding the floor continues to do so’ (Reference Ferguson1977: 296). This version of unsuccessful interruption has an equivalent within the sonic domain, where such sonic interjections are too weak or benign to pose a real threat to the pre-existing sound. These are very different to unsuccessful interruptions which have a stronger presence and pose a threat to the pre-existing due to their dynamic level, magnitude or force. See Movie 2.

3.3 Subliminal interruption

A variant of the unsuccessful interruption is the subliminal interruption (Figure 5), where a very brief, momentary sound, for example, a ‘click’ or ‘pop’, offers a brief, barely-there flash of audio that is not powerful enough to cease the continuity of the pre-existing drone decay sound (Figure 6).

Figure 5.

Graphic illustration, subliminal interruption.

Figure 6.

Audio region illustration – Subliminal interruption.

3.4 Successful interruption

For an interruption to be considered ‘successful’, the impact sound must crucially be perceived to cease the continuity of the drone decay sound. There are different configurations of successful interruptions (outlined below), which all demonstrate variation in what occurs at the point of the interruption.

3.5 Terminating interruption

In a terminating interruption (Figure 7), the occurrence of the impact prematurely ends the continuity of the drone sound. Importantly, there is no resumption of the drone decay (Figure 8). Terminating interruptions are finalising because they fully halt what was previously occurring. See Movie 3.

Figure 7.

Graphic illustration – Terminating interruption.

Figure 8.

Audio region illustration – Terminating interruption.

3.6 Transitioning interruption

Within a transitioning interruption (Figure 9), the impact sound terminates the drone decay sound prematurely and acts as a moment of transition by introducing a new oscillating texture. Figure 10 shows the drone decay sound being cut short by the impact, while the impact appears to initiate the entry of the oscillating texture. Placing an impact sound at this point offers some framing to the moment of transition, acting as a synchronised but sudden segue into new material. See Movie 4.

Figure 9.

Graphic illustration – Transitioning interruption.

Figure 10.

Audio region illustration – Transitioning interruption.

3.7 Temporary interruption

Within a temporary interruption (Figure 11), the impact ceases the continuity of the drone decay sound, so it ends prematurely. The impact, as an interruption, triggers a pause or a temporary silence, after which the drone sound then resumes. As a feature, temporary interruptions involve resumptions; however, these can pick up from the instance of the termination or may restart the pre-existing sound from the beginning (see Temporary interruptions with restarted resumptions). Figure 12 indicates the moment of silence in between the impact and the resumption of the drone’s natural decay. The length of the silence may vary from milliseconds to seconds. See Movie 5.

Figure 11.

Graphic illustration – Temporary interruption.

Figure 12.

Audio region illustration – Temporary interruptions.

It is worth noting that the use of volume envelopes within DAWs can result in an alternative audio region layout than what is shown in Figure 12. Volume envelopes are visible automation lines indicating the amplitude level of a track within a DAW. These can be drawn or altered with the positioning of nodes. The vertical position of a node upon an audio region indicates the amplitude at that moment in time. Figure 13 shows how volume envelopes would be implemented to achieve the same sound result as achieved in Figure 12.

Figure 13.

Temporary interruption utilising volume envelopes.

3.8 Temporary interruption with restarted resumption

A variant of the temporary interruption exists where the impact sound interrupts and prematurely ends the drone decay and triggers a silence; however, resumption takes the form of a restart of the drone decay sound. Restarting the drone sound is an attempt to articulate the drone decay in full, without an interruption. Figure 14 shows the drone decay sound restarting within the resumption phase.

Figure 14.

Temporary interruption with restart resumption.

3.9 Partial interruption

Interruptions in this category are only partially successful in ceasing the continuity of the pre-existing sound. Within a partial interruption (Figure 15), a drone sound and oscillating texture occur simultaneously. The impact prematurely interrupts the oscillating texture but does not cease the continuity of the drone decay. Figure 16 demonstrates the continuity of the drone sound which is not interrupted by the impact. In these instances, the effect is a sudden thinning of texture, which results in a partial drop-out, but without the imposition of a silence. See Movie 6.

Figure 15.

Graphic illustration – Partial interruption.

Figure 16.

Audio region illustration – Partial interruption.

If additional layers of sound are present in the initial stage, partial interruptions become especially intriguing. These overlapping sounds create a rich complexity that suddenly disappears when the interruption occurs, resulting in a more pronounced effect. In Figure 17, multiple sounds (oscillating texture, drone decay, granular texture and bass rumble) play together until an impact interruption silences all but one.

Figure 17.

Partial interruption variation (increased drop-out effect).

Figure 17. Long description

The image contains five separate waveform graphs, each representing a different sound effect and its drop-out effect. Panel A shows a waveform labeled ‘impact,’ characterized by a sharp peak that quickly tapers off. Panel B displays an ‘oscillating texture’ waveform, which features a repeating pattern of peaks and troughs. Panel C illustrates a ‘drone decay’ waveform, starting with a high amplitude that gradually decreases over time. Panel D presents a ‘granular texture’ waveform, consisting of numerous small, irregular peaks. Panel E depicts a ‘bass rumble’ waveform, with a consistent, low-frequency pattern that extends across the entire duration. Each waveform graph has a horizontal axis representing time and a vertical axis representing amplitude. The drop-out effect is indicated by a bracket at the bottom, showing the point where the sound suddenly stops.

3.10 Juxtaposition interruption

Within a juxtaposition interruption (Figure 18), two sonically different sounds are presented in sequence. The drone decay’s continuity is cut short by the appearance of a cymbal crash. The interruption is caused by the sudden transition between the two sounds. Figure 19 shows this juxtaposition occurring over two tracks. The same effect can be achieved in a side-by-side configuration. See Movie 7.

Figure 18.

Graphic illustration – Juxtaposition interruption.

Figure 19.

Audio region illustration – Juxtaposition interruption.

3.11 Suspension interruption

The suspension interruption (Figure 20) functions as a blend of the juxtaposition, partial and negative space interruptions, resulting in a complex design. Importantly, this type of interruption exhibits a frozen-in-time quality taking place in between the pre-existing and the resumption components. The interruption space is occupied by a static moment that appears to freeze the content between the pre-existing and resumption. This static moment has a connective function, reuniting two parts of the same sound, while placing the sound in a moment of suspension.

Figure 20.

Graphic illustration – Suspension interruption.

3.12 Masking interruption

In a masking interruption (Figure 21), the drone sound continues in its entirety; however, a louder, more present sound, for example, the sound of a helicopter’s rotor blades, is layered over the drone decay, which masks the drone’s frequency content. In masking interruptions, the interruption takes the form of a more powerful, louder sound that eclipses the sound of the pre-existing, even though the pre-existing is still present within the mix. Figure 22 demonstrates the overpowering nature of the helicopter sound, which has a bigger amplitude indicated by the size and heaviness of its waveform. Whilst the layering of audio is visibly enacted, the audibility of this layering is not always wholly apparent. Within masking interruptions, the sounding result can be one of audio obliteration, where the interruption overpowers the pre-existing either through volume and presence, or through competing frequencies where multiple sounds can occupy the same range of sonic frequencies, leading to frequency masking and loss of clarity. This overpowering behaviour resonates with Horrigan’s discussion of ‘sonic dominance’ and ‘sonic interruptivity’, where interruption is understood as one of sound’s capacities to intrude upon, dominate or redirect attention within a given environment (Reference Horrigan2022: 219). In masking interruptions, this dominance is enacted materially where the interrupting sound does not remove the pre-existing sound but occupies its perceptual space. See Movie 8.

Figure 21.

Graphic illustration – Masking interruption.

Figure 22.

Audio region illustration – Masking interruption.

3.13 Negative-space interruption

Within negative-space interruptions, silence features as a gap appearing within the pre-existing sound. There are two variants termed as ‘cut-outs’ and ‘segmentations’. In both instances, it is notable that a sonic interruption is absent (so far, I have described these as impact sounds) and, instead, interruption is achieved by the interjection of silence and empty space resulting from audio extraction or segmenting a sound into smaller sections. In these cases, the space without sound (the void) itself becomes the moment of interruption. See Movie 9.Footnote ³

3.14 Cut-out interruption

In a cut-out interruption (Figure 23), the drone decay sound is subjected to a removal of its content so that a space or gap appears within its morphology. The effect achieved is a sudden drop-out of sonic content – a silence. Figure 24 demonstrates the absence of a chunk of the drone decay sound. After the silence, the drone sound resumes. The duration of a cut-out interruption is variable, and different effects can be achieved by reducing or extending this extraction. A gap of a few milliseconds offers a subliminal cut-out interruption, whereas a lengthier gap of three or four seconds can leave audiences wondering if the sound has finished through termination.

Figure 23.

Graphic illustration – Cut-out interruption.

Figure 24.

Audio region illustration – Cut-out interruption.

3.15 Segmentation interruption

Segmentation interruptions are like cutout interruptions; however, they involve making an incision within the pre-existing sound rather than extracting audio from the original soundfile. The drone decay sound is cut using the edit tools (scissor/cut), and then the two parts of the sound are separated or pulled apart in the linear timeline. This action creates a void in between the two previously connected segments. While belonging to the same order of negative space interruptions, segmentation interruption creation is distinctly different since it does not involve the removal of sonic content to create the silence but instead involves the insertion of silence. Figure 25 shows the process of making an incision and the subsequent separation of the two segments.

Figure 25.

Segmentation interruption.

3.16 Processing interruption

A processing interruption occurs when the pre-existing sound is subjected to a processing tool, for example, a stutterer, granulator or slicer. The processing tool breaks apart the drone decay’s continuity and achieves an iterative, rearranged quality. The waveform of a processing interruption may exhibit a string of micro-interruptions, closely packed together, as demonstrated in Figures 26 and 27. See Movie 10. The effect of interruptions occurring in succession is described in more detail in a later discussion (see successive interruptions).

Figure 26.

Graphic illustration – Processing interruption.

Figure 27.

Audio region illustration – Processing interruption.

4.1 The causality of interruptions

The concept of causality plays a significant part within the making of sonic interruptions. Smalley describes causality ‘where one event seems to cause the onset of a successor or alter a concurrent event in some way’ (Reference Smalley1997, 118) and is widely accepted as fundamental to the language of acousmatic music. Establishing causality demands some understanding of the ‘voluntary-pressured continuum’ (Ibid.: 119) within acousmatic music. This terminology can be best explained by imagining the placement of individual sounds along a horizontal timeline and then altering the distance between these sounds. Within a voluntary motion passage, two sounds may be far apart, with distance separating their occurrence, whereas in a pressure motion passage, two sounds might be tightly packed, close in proximity so that one sound exerts a pressurising urgency upon the next, appearing to influence its occurrence. As my illustrations of interruptions have shown, it is the presence of the impact sound that commands the pre-existing (before) sound to cease. Thus, the causal relationship is deemed somewhat ‘inverted’, providing a more appropriate descriptor for the impact’s effect on the previous sound (Figure 28).

Figure 28.

Inverted causality within a successful interruption.

Inverted causality is important for interruption making since their clout comes from their surprise entry and unexpectedness. In this regard, in a successful interruption, the pre-existing sound should give no clues of an interruption’s forthcoming appearance. By way of a helpful reminder, Proy acknowledges that ‘in the acousmatic situation we do not have a [visual] causal element that supports our interpretation. There is no movement of the violin bow which makes us expect the sound. In the acousmatic situation we are touched by sounds unexpectedly’ (Reference Proy2002: 16). Thus, the ambition to create unexpected interruptions capitalises on the absence of visual information and further avoids signals or preparations which might give away the moment of surprise. The thinking around how to establish these unexpected sounds draws on heuristic knowledgeFootnote ⁴ which refers to ‘imperfect rules of thumb about what is likely to happen next’ and knowing how different sounds lend themselves to certain situations within the acousmatic situation. Given that ‘one of the great successes of acousmatic music is in its capacity to establish anticipation and expectation’ (Andean Reference Andean2020: 215), I am certain of the compositional knowhow in circulation to offer the inverse, when seeking to deny such predictability. Nolan Hildebrand’s composition, Amygdala Hijacker (2026) is one such example which exploits audio situations that lack predictability by establishing a series of unprepared audio jump scares, where sharp bursts of sound interrupt passages of silence (see sound example 8). It is worth noting that sounds which rise or descend, increase, crescendo or generally intensify over time are regarded as anticipation and tension builders that tend to result in an event or release at the end of their trajectory. This arrangement of sound offers excellent gestures known as ‘graduated continuants’ or ‘reverse attack decay’ archetypes. These, however, are not interruptions as such. Placing an impact sound at the mid-point or end of one of these ‘builds’ would not strictly achieve a successful interruption, since expectation of an event has been determined with causality already in progress. In other words, the element of surprise has already been diminished. What works more effectively is the selection of a sound that is void of this build-like quality and something that possesses a wholeness or totality that one would expect to hear in full. Such sounds might include the sounds of a train chugging along a track, eggs frying in a pan, footsteps running through a long corridor, water trickling from a fountain and shopping centre ambienceFootnote ⁵ as audio content that meets this criterion of regular, continuous sound. In choosing such sounds as candidates to be interrupted, it becomes possible to set up what Huron calls a ‘violation of expectation’ (Reference Huron2006: 26). Establishing a moment of surprise in acousmatic music is thus an attempt to thwart one’s expectation of a sound’s typical lifespan and behaviour so that we might encourage a [listening] failure to accurately anticipate possible future events (Ibid.: 39).

4.2 The illusion of interruption

A key objective in crafting interruptions is to empower the impact sound (the interruption) with an enhanced, unnatural capacity to disrupt existing auditory environments and effectively terminate the pre-existing sound prematurely. The synchronisation of the impact’s entry at the precise moment where the pre-existing sound is cut within the DAW results in a satisfying coincidence, fusing the two sequential sounds into a new, cohesive, but entirely illusory musical unit. These highly arranged moments establish a perceived aural illusion of interruption, where a break in continuity is seemingly caused by another sound. This aural result or perception overrides the technological reality of the situation, which was created by a human operating a scissor-tool edit at this precise moment, which severed the sound, rather than the impact sound, which has carefully been juxtaposed at this precise edit point. Bestowing sounds with the illusion of termination is thus the goal, achieved by the composer through this precision act of sound arrangement.

4.3 Sounds and their interrupters

When analysing how an interruption is created together with its element of surprise, it is also necessary to consider where to position the interruption. So far, I have mentioned that the interruption needs no clue or hint of its entry from the pre-existing to maintain its element of surprise. I have also suggested that delaying an interruption’s entry towards the end of the pre-existing’s natural trajectory also does not achieve the status of an interruption, since the sound is naturally coming to an end and is conforming to our expectations of how sound progresses and organically ends. To play with expectations of how or if a sound’s completeness will unfold, it may be useful to first consider what type of sound is being used in the first instance, as mentioned above, and there are certain attributes to look out for before deciding where an interruption should be placed. To demonstrate, I will use the example of a sound recording of a car driving by at high speed which taps into our understanding of this trajectory as experienced that typically moves across the stereo window, from left to right or right to left. Severing this motion partway through the car’s trajectory with an interruption breaks the continuity and violates our understanding of this sound, as experienced in the real world. This aesthetic approach to creating and handling gesture in acousmatic music creation embraces the more unconventionally placed cut and develops a feature from it to revel in the discontinuity and momentum that results from such severing.

4.4 From corrective editing to sculptural cutting

Traditionally, the cut has often been framed as a corrective editing technique: a means of removing imperfections, unwanted noise or extended silences between takes (McNally and Gaskell Reference McNally and Gaskell1984; Langford Reference Langford2013). This pragmatic understanding has a longer history in Schaeffer’s Traité des objets musicaux (2017 [1966]), particularly in relation to his concept of the ‘sonorous object’. As Schaeffer observed, ‘any new object after a cutting will have a head, a body, and a tail’, comparing the cutting of a sonorous object to the cutting of a magnet into smaller parts, where ‘each of the new magnet parts will have their respective polarisations’ (Schaeffer, quoted in Godøy Reference Godøy2006: 151). Cutting is thus not just a removal process but an action that produces new objects with their own morphological properties. At the same time, Schaeffer acknowledged that arbitrarily extracting a fragment from a continuous stream of sound could produce artefacts, suggesting that ‘sonorous objects should be cut at what could be considered “natural” discontinuities in the continuous stream of sound, by the principle of stress-articulation’ (Schaeffer stated in Ibid.: 151). Although stress-articulation was originally significant for sound analysis and for transforming the perception of the sound object, its principles continue today in pragmatic editing practices, where waveform views help identify attacks, transients, zero-crossings and natural points of discontinuity or termination.

Contemporary writing on cutting sound belongs largely to the discourse of audio editing, often appearing in music production manuals that present editing as a preparatory activity prior to the creative process. Elsea, for example, focuses on the practicalities of setting edit points accurately. Of relevance is his demonstration of a ‘bad splice’ (Reference Elsea2013: 78), where a cut made at a non-zero crossing point can produce an undesirable click or pop. This identifies a possible risk of abrupt editing: the technological artefact. However, it is important to distinguish between a cut that is technically flawed because it introduces unwanted artefacts, and a cut that is aesthetically abrupt, aggressive or obvious. The removal of clicks does not necessarily imply a desire for smooth or unobtrusive musical transitions; it may simply reflect the wish to avoid unintended noise. A click-free cut can still be instantaneous, forceful and brutal to the ear. Elsea notes that ‘some audio editors approach this problem by overlapping and blending the ends of clips (crossfading) whenever you perform an operation. This harkens back to tape editing, where we always made the cut on an angle to produce a short crossfade’ (Ibid.). Such techniques remain fundamental to transparent editing and to the adage of the ‘inaudibility of good sound editing’. The vertical edits appearing in my typology, however, sit outside these principles. They represent a deliberate aesthetic use of abruptness rather than examples of faulty editing. There is therefore a degree of non-compliance within sonic interruption that runs contrary to the norms and protocols associated with ‘good’ sound editing.

Of course, I am not the first to break with such editing conventions as similar procedures appear in the abundance of harsh cuts within noise and glitch music, as well as in the filmic practice of montage, which emerged in the 1920s through Soviet cinema. Montage films exhibited assemblages of shots where the editing rather than the content of the shot alone constituted the force of a film. As Bordwell notes, ‘the theory of montage, viewed most abstractly, can be applied outside film. The fundamental principles-assemblage of heterogeneous parts, juxtaposition of fragments, the demand for the audience to make conceptual connections, in all a radically new relation among parts of a whole-seem transferable to drama, music, literature, painting, and sculpture’ (Reference Bordwell1972). While Bordwell’s comment primarily concerns the meaning-making potential of juxtaposition, it is the bluntness of the cut that enables such relations to become perceptible. Montage therefore provides a useful historical reference point for the creative appropriation of ‘bad’ or aggressive editing. It is understandable, then, that many editing traditions have sought to keep the cut unobtrusive so that it does not call attention to itself or reveal the hand of the composer, producer or underlying technology. My atypical compositional cuts move in the opposite direction. Rather than serving pragmatic or corrective purposes, such as audio cleanliness or the pruning of imperfections, they are applied with sculptural intentions, cutting into the often usable ‘flesh’ of the sound in search of new forms and sonic interest.

4.5 The interruption as spectromorphological termination

The visual schematics of interruptions within the sonic domain shown at the beginning of this article demonstrate an inherent linkage with Smalley’s spectromorphological concepts, most specifically with his ‘structural functions’ terminology. My earliest writings and contributions to the discourse of acousmatic composition methodologies were concerned with transforming Smalley’s spectromorphological terminology into illustrated form to visually represent the structures composers can create when composing with sound. This contribution (Blackburn Reference Blackburn2011) introduced the basics of shaping a single sound or piecing together sound units from multiple sounds, all using terminology as an influential guide (Figure 29 demonstrates the construction of a sound unit from three sounds identified as an upbeat, statement and disappearance).

Figure 29.

An example sound unit construction (Blackburn Reference Blackburn2011: 7).

This new contribution goes further in attempting to demonstrate the sculpting of sound, using interruptions as the main device. In the case of terminating interruptions, the visualisation (Figure 7) shows how this sound event operates similarly to a typical sound unit, with observable onset, continuant and termination components. In this example, the termination is the interruption, which brings the pre-existing sound to an end. Through the lens of spectromorphological thinking, all interruptions within the sonic domain are essentially terminations. These two structural components share behaviours and functionality. Of key importance is that both terminations and interruptions have the ability to halt the continuity of the pre-existing sound. It is worth noting, however, that not all terminations are interruptions. Smalley’s indication of termination differences makes this point clear by stating that ‘terminations vary in their feelings of completion. “Disappearance” is a weak termination without much purpose, while “resolution” and “release” have strong relaxant functions. “Arrival” and “plane” express structural goals achieved’ (1997:115). By pointing out a termination’s strength and assertiveness, we are better able to observe a sonic form of ‘brute force’ as a necessary attribute for a sound which qualifies as an interruption and not all terminations qualify as such. The words ‘termination’ and ‘interruption’ are thus not interchangeable. Another point within this argument is Smalley’s discussion of a sound’s function attribution which ‘may be double or ambiguous’. In reference to my discussion of sonic interruptions, it would be perfectly acceptable to regard the interruption (e.g. an impact sound) as both a termination to the pre-existing sound and as an onset, in its own right. When consulting Smalley’s structural functions vocabulary for onsets, these words are immediately better suited to describe an impact that has a clear attack-like profile. Double function attribution is something I have previously commented on in relation to morphological stringing, where I claim that it is inevitable that sounds will take on dual roles within a string of successive sound units (Blackburn Reference Blackburn2011). A similar situation arises when discussing interruptions since they both halt the pre-existing sound and, in themselves, are onsets or onsets to new material, for example, as found in transitioning interruptions.