Sound Examples Research Articles

An exploration for deep-sea fish sounds off Vancouver Island from the NEPTUNE Canada ocean observing system

Our understanding of the significance of sound production to the ecology of deep-sea fish communities has improved little since anatomical surveys in the 1950s first suggested that sound production is widespread among slope-water fishes. The recent implementation of cabled ocean observatory networks around the world that include passive acoustic recording instruments provides scientists an opportunity to search for evidence of deep-sea fish sounds. We examined deep-sea acoustic recordings made at the NEPTUNE Canada Barkley Canyon Axis Pod (985m) located off the west coast of Vancouver Island in the Northeast Pacific between June 2010 and May 2011 to determine the presence of fish sounds. A subset of over 300 5-min files was examined by selecting one day each month and analyzing one file for each hour over the 24h day. Despite the frequent occurrence of marine mammal sounds, no examples of fish sounds were identified. However, we report examples of isolated unknown sounds that might be produced by fish, invertebrates, or more likely marine mammals. This finding is in direct contrast to recent smaller studies in the Atlantic where potential fish sounds appear to be more common. A review of the literature indicates 32 species found off British Columbia that potentially produce sound could occur in depths greater than 700m but of these only Anoplopoma fimbria and Coryphaenoides spp. have been previously reported at the site. The lack of fish sounds observed here may be directly related to the low diversity and abundance of fishes present at the Barkley Canyon site. Other contributing factors include possible masking of low amplitude biological signals by self-generated noise from the platform instrumentation and ship noise. We suggest that examination of data both from noise-reduced ocean observatories around the world and from dedicated instrument surveys designed to search for deep-sea fish sounds to provide a larger-scale, more conclusive investigation into the role, or potential lack thereof, of sound production.

Multiobjective Time Series Matching for Audio Classification and Retrieval

Seeking sound samples in a massive database can be a tedious and time consuming task. Even when metadata are available, query results may remain far from the timbre expected by users. This problem stems from the nature of query specification, which does not account for the underlying complexity of audio data. The Query By Example (QBE) paradigm tries to tackle this shortcoming by finding audio clips similar to a given sound example. However, it requires users to have a well-formed soundfile of what they seek, which is not always a valid assumption. Furthermore, most audio-retrieval systems rely on a single measure of similarity, which is unlikely to convey the perceptual similarity of audio signals. We address in this paper an innovative way of querying generic audio databases by simultaneously optimizing the temporal evolution of multiple spectral properties. We show how this problem can be cast into a new approach merging multiobjective optimization and time series matching, called MultiObjective Time Series (MOTS) matching. We formally state this problem and report an efficient implementation. This approach introduces a multidimensional assessment of similarity in audio matching. This allows to cope with the multidimensional nature of timbre perception and also to obtain a set of efficient propositions rather than a single best solution. To demonstrate the performances of our approach, we show its efficiency in audio classification tasks. By introducing a selection criterion based on the hypervolume dominated by a class, we show that our approach outstands the state-of-art methods in audio classification even with a few number of features. We demonstrate its robustness to several classes of audio distortions. Finally, we introduce two innovative applications of our method for sound querying.

Sound and movie examples – issue 18(2)

Sound and movie examples – issue 18(2)

Different Resistances: A Comparative View of Indian and Western Classical Music in the Modern Era

If the notion of resistant materials in music has a Western modernist subtext, an alternative perspective is offered by Hindustani classical music. The latter's principal means of cultural transmission, the master–disciple tradition (guru–śiṣya paramparā), would ostensibly find resistance a foreign concept. Yet this precolonial tradition paradoxically played a part in the rise of Indian modernity, bound up as this was with resistance to British colonialist hegemony. Recording technology also played a role in this process, and, in its evolving forms, has been a (modernising) determinant on how Hindustani classical practitioners shape their materials in improvised performance. Analysis of a recorded rāga rendition can reveal just how extensively the formation of materials involves various forms of immanent resistance. Thus, allied to both conservation and emancipation, resistance can ultimately be seen to play a role no less formative on Indian than on Western music, albeit differently so. The text is supported by sound examples which appear as supplementary material accessible online via the article's Supplementary tab on the Taylor & Francis website (http://www.tandfonline.com/loi/gcmr).

Sound and movie examples – issue 17(3)

Sound and movie examples – issue 17(3)

Non-diegetic sound effects

Most films tell a story. This story takes place in a constructed world that only exists in each specific film. It makes no difference if the story is set in a fantasy world, a historical or a future world, or even if it's a documentary that depicts reality. Every film still creates its own filmic world, its diegesis. Everything which happens inside this world is called diegetic and what happens (in the movie) outside this world is called non-diegetic. Traditional film music and voice-over narration are typical examples of non-diegetic sounds. The characters in the film are unaware of them, because they don't exist in the same world. These sounds are messages from the filmmaker directly to his/her audience. Music played inside the film's world, for example by visible musicians or from a radio seen on screen, is diegetic, as is dialogue and sound effects. The characters in the film are meant to be aware of these sounds. Whether the actors heard these sounds while shooting the scenes or if they where added during sound editing, they influence the audience's interpretation of the characters, the situation and the narrative.

Automatic Composition of Electroacoustic Art Music Utilizing Machine Listening

This article presents Autocousmatic, an algorithmic system that creates electroacoustic art music using machine-listening processes within the design cycle. After surveying previous projects in automated mixing and algorithmic composition, the design and implementation of the current system is outlined. An iterative, automatic effects processing system is coupled to machine-listening components, including the assessment of the “worthiness” of intermediate files to continue to a final mixing stage. Generation of the formal structure of output pieces utilizes models derived from a small corpus of exemplar electroacoustic music, and a dynamic time-warping similarity-measure technique drawn from music information retrieval is employed to decide between candidate final mixes. Evaluation of Autocousmatic has involved three main components: the entry of its output works into composition competitions, the public release of the software with an associated questionnaire and sound examples on SoundCloud, and direct feedback from three highly experienced electroacoustic composers. The article concludes with a discussion of the current status of the system, with regards to ideas from the computational creativity literature, among other sources, and suggestions for future work that may advance the compositional ability of the system beyond its current level and towards human-like expertise.

Sound and movie examples – issue 17(2)

Sound and movie examples – issue 17(2)

Attraction by sound—examples on the negative acoustic radiation forces of Bessel “tractor” beams on a sphere

Expressions for the axial (i.e. acting along the axis of wave propagation) and transverse (lateral) acoustic radiation forces on a suspended object in an ideal fluid are derived for arbitrary shaped beams. These expressions are obtained from the integration of the radiation stress tensor in the far-field. Numerical examples on non-vortex and vortex Bessel beams on a spherical target are presented. It is demonstrated the existence of both “pushing” and “tractor” behaviors for which the axial force can be oriented, respectively, along the direction of wave propagation or opposite to it. This can be adjusted by choosing specific values of the beam cone angle and the sphere size factor ka (where k is the wavenumber and a is the sphere's radius). Furthermore, by changing the topological charge m of the beam and the position of the sphere, the transverse force may be oriented radially (outward or inward) for m=0 or may exhibit a vortex pattern for m ≥ 1.

Time domain simulation and sound synthesis for the snare drum

The snare drum is a complex system, relying on the interaction of multiple components: the drumheads, or membranes, a set of snares, the surrounding acoustic field and an internal cavity. Because these components are multidimensional, and due to a strong distributed non-linearity (the snare interaction), many techniques used frequently in physical modeling synthesis applications, such as digital waveguides and modal methods are difficult to apply. In this article, finite difference time domain techniques are applied to a full 3D system, and various features of interest, such as the coupling between membranes, and the interaction between the membranes and the snares, are examined in detail. Also discussed are various numerical features, such as spurious splitting of degenerate modes and bandwidth limitation, and estimates of computational complexity are provided. Sound examples are presented.

Effects of Consensus Training on the Reliability of Auditory Perceptual Ratings of Voice Quality

This study investigates the effect of consensus training of listeners on intrarater and interrater reliability and agreement of perceptual voice analysis. The use of such training, including a reference voice sample, could be assumed to make the internal standards held in memory common and more robust, which is of great importance to reduce the variability of auditory perceptual ratings. A prospective design with testing before and after training. Thirteen students of audiologopedics served as listening subjects. The ratings were made using a multidimensional protocol with four-point equal-appearing interval scales. The stimuli consisted of text reading by authentic dysphonic patients. The consensus training for each perceptual voice parameter included (1) definition, (2) underlying physiology, (3) presentation of carefully selected sound examples representing the parameter in three different grades followed by group discussions of perceived characteristics, and (4) practical exercises including imitation to make use of the listeners' proprioception. Intrarater reliability and agreement showed a marked improvement for intermittent aphonia but not for vocal fry. Interrater reliability was high for most parameters before training with a slight increase after training. Interrater agreement showed marked increases for most voice quality parameters as a result of the training. The results support the recommendation of specific consensus training, including use of a reference voice sample material, to calibrate, equalize, and stabilize the internal standards held in memory by the listeners.

Sound and movie examples – issue 16(2)

Sound and movie examples – issue 16(2)

Perception of scattering coefficient in auralized concert halls.

The scattering coefficient has become a determinant parameter in room acoustic software because it enhances the precision of simulation results. Although there is a wide agreement on the necessity of using scattering coefficients for characterizing surfaces and pattern elements within an enclosed space such as a concert hall, there is still a lack of knowledge on the influence of this on the human perception. The primary purpose of this study is to investigate how changes in scattering coefficients of diffusing surfaces could possibly affect the perception of music among the audience in concert halls. A simplified shoebox‐like geometry was used to generate binaural room impulse responses under various scattering conditions for different seats. Computer simulation results were convolved with sound examples, which were properly selected as representative of typical music textures. Results from listening tests will be shown and discussed.

Pre-Colombian and traditional Mexican wind instruments.

Wind instruments such as flutes were known in ancient Mexico 3000 years ago. When the Spaniards arrived, pre-Colombian cultures used many kinds of ceramic peak flutes of one, two, and three tubes, made by the musicians themselves, who played them and break them down at the rituals. Other wind instruments were so-called ocarinas as well as all kinds of whistles with the most exotic sounds, like the death-whistle. They also knew some kind of lip-vibrated instruments, made from seashells or wood and other materials. Seashell trumpets were also copied in clay and made them to be blown in the same way as the original instrument. The Spaniards destroyed as much as they could of the native culture and introduced their own, mainly through religion: music was an essential part of Catholic service. Pipe & tabor and shawms were widely used. Those instruments became part of the cultural heritage of the natives and we can hear them play today. This presentation will show pre-Colombian wind instruments, with sound examples, diagrams, and acoustical analysis made by different scholars, as well as traditional and ethnographic wind instruments made with natural materials used at present times.

Analysis and Synthesis of Coupled Vibrating Strings Using a Hybrid Modal-Waveguide Synthesis Model

The linear coupling of two strings or of a single string vibrating in two orthogonal polarizations leads to two observable phenomena: two-stage decay and beating. In this paper, we present methods for accurately measuring and modeling the lower partials of a recorded guitar tone, where coupling effects are most audible. These estimated parameters are then used for accurate resynthesis in a hybrid modal/waveguide model. We make use of the fact that two-stage decay occurs in analyzed tones to allow direct measurement of sinusoidal decay rates. A traditional iterative optimization algorithm is explored and found to be most effective in the special case when only beating occurs. Sound examples are provided on the Web.

Sound and movie examples – issue 15(1)

Sound and movie examples – issue 15(1)

An Instrumented Saxophone Mouthpiece and its Use to Understand How an Experienced Musician Plays

An instrumented saxophone mouthpiece has been developed to measure, during the player’s performance, the evolution of important variables : the mouth pressure, the mouthpiece pressure and the force applied on the reed by the lower lip. Moreover, according to the pressure signals in the mouth and in the mouthpiece, the instantaneous ratio of the vocal tract input impedance and of the saxophone input impedance is estimated at frequencies multiple of the playing frequency (using the concept of Gabor mask). On the selected sound examples, analyses reveal many aspects of the strategies of the player. First of all, the role of the vocal tract in the characteristics of the sound production is sometimes prominent. Secondly, the sound production on the desired note (and register) as well as pitch correction seem to be the result of complementary adjustments of the mouth pressure and of the lip pressure on the reed. This is not in agreement with musicians feeling, since they often claim to let their force on the reed unchanged during the note and from note to note.

Sound and Movie Examples – Volume 14 (Issue 14/3)

Sound and Movie Examples – Volume 14 (Issue 14/3)

The ‘open-earedness’ hypothesis and the development of age-related aesthetic reactions to music in elementary school children

This study investigates age-related changes in musical preference in elementary school children. The tolerance towards unconventional musical styles has been called ‘open-earedness’ (Hargreaves, 1982a), and it is assumed to decline with increasing age. Musical preferences of 186 students from grade 1 to 4 (age range: 6–10 years) were measured by using a 5-point iconographic rating scale. Eight sound examples were presented in a sound questionnaire. Results showed a decline of open-earedness for unconventional music (classical, ethnic and avant-garde music) from grade 1 to 2 (age: 7–8 years). However, this effect disappeared when classical music was excluded from data analysis. Only a few absolute rejections of unconventional musical styles were found, and the mean preference ratings did not exceed the neutral mean range. Future studies will have to consider additional factors of influence to make clear predictions about the point in time when this transition occurs.

Applications of passivity theory to the active control of acoustic musical instruments

The dynamic behavior of any acoustic musical instrument can be modified by closing a feedback loop around even a single sensor and actuator. The ultimate goal is to make the acoustics of the instrument programmable by way of a digital feedback controller, while the instrument retains its tangible form. In this talk, we describe a class of controllers that are applicable to passive acoustic musical instruments, and we present sound examples from laboratory experiments on a vibrating string. First, we briefly introduce positive real functions. Next, we design positive real controllers allowing the quality factor and resonant frequency of instrument modes to be individually controlled. Because positive real controllers are passive, they are stable if the instrument is passive. This means that neither a full instrument model nor complete state measurements are required. Finally, we describe a class of simple passive nonlinear controllers that can emulate various kinds of friction, stiffening and softening springs, etc. Passivity of these controllers follows from the local passivity of the controller components. Controller parameters may often be tweaked so that the controllers are no longer passive but still perform useful functions, such as bowing emulation.