Monday, October 24, 2011
Close Miking Consciousness: Imaginary Experiments with Space, Place, Shapes & Mics
by Gautam Pemmaraju
In sound and music production, close miking refers to the practice of placing the microphone close to the sound source – from 1 inch to 1 foot – as opposed to distant or ambient miking. There are several kinds of microphone techniques, countless kinds of specialty microphones to suit a wide range of purposes, and given the sheer complexity of the human relationship to sound, the applicability of technology (in what situations we record sound and with what) assumes great import. It is a pretty vast creative domain and is shaped by the imagination of those at work. Close miking suggests here a greater intimacy with process and perception. In order to extrapolate more or finer detail, we go closer to the sound - physically, psychologically and metaphorically. It is through a more intimate engagement with sound that we then ascribe character to it – we discuss texture, tonality, timbre, colour, and taste even. We use every other sense to describe how a sound sounds.
One elemental way we can understand hearing is as a function of Signal to Noise or SNR (see this). When noise escalates or overwhelms, we instinctively adapt. Needless to say, in cities, with a profusion of countless impulses, signals and provocations, we are in a perpetual condition of negotiating this balance, whereby, we recalibrate, reassign priority, and in many ways, incessantly rehear our environment. We find ways to suppress background noise and achieve comprehension and intelligibility. What do we then hear in our heads as opposed to what we hear out of our heads? Such a question is inextricably linked to our broader, composite perception – it informs speech and vision. The McGurk-McDonald Effect (see this BBC Horizon video clip) underscores these complex relationships, whereby, when one phoneme was dubbed over the video of a different one spoken out, an entirely third one was perceived when the video was played back.
We move through cities performing our quotidian tasks - turning street corners, riding trains, rickshaws and taxis, buying groceries, eating out, conducting business, walking seaside promenades (if such a luxury is on offer), listening to lovers tiffs in the neighbouring flat, meeting friends for drinks at bars, etc. Possessed with the incredible ability to localize sound selectively (see Cocktail Party Effect and this), binaurally, and with great acuity, we are able to process a mind-boggling number of impulses simultaneously. Different sounds come to our ears differently and while both ears work in collusion, they work also independently. Interaural time difference, the shapes of our heads, the shapes of our individual ears (see Head Related Transfer Function or HRTF), the shapes of rooms, the shapes of reflecting objects within rooms, the shapes of buildings, the terrain, the topography – almost everything matters. Certain noises degrade speech, and we then find ways to ‘learn the noise’.
So in our multiple inhabitations of the city, what is it that we hear? What shapes shape our sounds? What sounds shape our minds? What shapes our consciousness? And interestingly, can we mike it?
Here are a few imaginary experiments based on microphone technique and elementary psychoacoustic principles in which we attempt to ‘learn the noise’ of the city, mike it and conduct it, and thereby, ‘learn the city’ in more intimate ways.
I. Binaural Beat City:
When two tones of relatively lower frequencies (below 1000 Hz) and marginally different (say 440 Hz and 436 Hz) are applied separately to the ears of a listener through earphones, the brain will perceive a beating tone - an ‘apparent sound’; an induced FFR, Frequency Following Response. (Take a listen using head/earphones here; see also this). Discovered by Heinrich Wilhelm Dove in 1839, binaural beats continue to be an interesting area of inquiry, speculation, and experimentation, not to mention kooky claims. We localize sounds in fascinating ways – for low frequencies, it is primarily by a difference in phase between the two ears, i.e., longer wavelengths result in the sound ‘wrapping’ or diffracting around the head; and in higher frequencies, we detect the source through intensity and utilize ‘direction finding’ by turning our heads because the ‘ear in shadow’ receives lesser information. In Gerald Oster’s seminal work Auditory Beats In The Brain (1973), he writes that although ‘noise’ masks the sounds we want to hear, it enhances the perception of binaural beats (which may be perceived even if below ‘the threshold of hearing’).
Listening to binaural beats produces the illusion that the sounds are located somewhere within the head. This in itself is hardly extraordinary: when music is played through stereophonic earphones, the orchestra seems to be somewhere in the head rather than “out there”. It is intriguing, however, that when the beats are very infrequent, fewer than about three per second, they seem to move back and forth in the head. If the intensities of the two tones are different, the motion takes an elliptical path.
Discussing the neurological basis of binaural beats, Oster refers to the ‘Telephone Theory’ as formulated by W Butherford in 1886, wherein it was postulated that sound is transduced by the ear much like a microphone does – acoustic impulses are converted into electrical ones. A second aspect to consider here for experimental purposes is that pure sustained tones (sine waves) rarely occur in nature but must be constructed mechanically/electronically. (Pure tone birdsong is common; musical instruments can produce pure tones).
Our first experiment is to find and record a multiplicity of sounds within the city, create sustained tones out of them by extracting/sampling/sequencing and then pair binaural tones (40 Hz – 44 Hz; 210 Hz – 212 Hz, etc). We deploy 30 technicians with field recording devices and directional field recording microphones (or capsule system - AKG SE 300B) such as the AKG CK 98, Sennheiser 816, AT 897, etc to assigned locations around the metropolitan area. Effective side and back rejection allows for such microphones (see polarity patterns here), to ‘pick out’ specific sounds as well as ‘look’ for others. These sonic purveyors (they will assume a level of inventiveness and adaptability over time), skilled at field recording (minimum handling noise is critical as is awareness of Proximity Effect), then transmit/upload their recordings from the field to a centralized production studio/hub. The relatively ‘clean’ sounds are further cleaned up for any extraneous noise (low-pass filter, gate, tone detector, etc), notch filters are applied, and from this multifrequency sound, a pure single tone is filtered down and sustained tones are created (some process of suppressing the harmonic overtones must be applied to extract a pure tone – an extraction algorithm? Is this possible?). As for the kind of sounds, we have for example, a lightman fixing up a 1Kilowatt light for a shoot in Studio No 1 of Mehboob Studios in Bandra. There are several discrete sounds to be had there – the turn of the clamp to secure the light, the movement of the barn doors, the turn of the focus knob on the back of the light, the turning of the light itself. On any given day in this city, there are over a thousand lightmen across hundreds of shooting units, perched precariously on top of scaffolding, without harness, affixing lights. Highly skilled, their industrious efficiency is but one part of a mammoth machine. The selection/collation of sounds itself is a broad spectrum exercise, but it is necessarily restricted to low frequency ones since the binaural beat effect diminishes as the tones approach 1000Hz. From the ship-breaking yards of Mazagaon, office canteens and ‘lunch homes’, the jewelery/diamond markets of Zaveri Bazaar, the ‘ching’ of mechanical taxi/rickshaw meter flags (which may be down-pitched for a cheat), the ‘typists’ outside the many city courts who industriously prepare pleas and petitions for supplicants, the humdrum of the countless beer bars and permit rooms, the civic workers who turn giant ‘keys’ to regulate water supply, to the preparatory cutting of vegetables by working women on local trains as they head back home – there are diverse sounds that may be apprehended here, as long as they are isolated, distinct, and not muddled by ambient noise.
There are all kinds of claims about the therapeutic qualities of binaural beats. Oster himself suggests a clinical use, on the basis that some neurological patients that he had examined were unable to hear binaural beats. There are all kinds of self-styled gurus and binaural beat evangelists who offer ‘healing sessions’ – periodic audition is meant to cure all manner of ailments. (Binaural Beat Astral Projection?). Others though suggest that, at best, they are able to aid more focused mental states, similarly to meditation or mild hypnosis.
It is not as therapy I then suggest, as part of this experiment, that the binaural pairs produced in the central hub are sent to remote listening kiosks set up in different parts of the city, one each in a focal point of the sound purveyor’s operational terrain. Residents walking by may step into these booths momentarily, choose ‘Spoon at Good Luck Cafe’ or ‘Light at Famous Studios’ from a touch screen, wear the earphones, and listen to the binaural beats generated by the city. As much as we listen selectively when we walk the streets of the city, these intervening auditions will suggest an alternate auditory reality, a conceptual shape of the city. Experiments with binaural recordings of city sounds (and others) are abundant and mostly involves recording sound using binaural microphones (see this, this, this, and this). The experiment here differs in that it is predicated on the successful extraction of pure tones from discrete recordings around the city, and then paired with an appropriate accompanying tone to possibly induce a binaural beat experience within the listener.
II. Auditory Cartography
The second experiment here involves auditory mapping of a neighbourhood, street, or even structure. Let us take for example the Mehboob Studio area in Bandra West, a western suburb of Bombay. This film studio complex has two main structures, six shooting floors, offices, open parking space, a poorly tended to lawn, and a canteen. Using a coincident paired microphone technique (Mid-Side in this case; others include X-Y, Blumlein) wherein the Mid microphone is a directional cardioid picking up sound in front, and the Side is bidirectional picking up sounds from either side, we then record a stereophonic image of each shooting floor. When heard back (with eyes closed), we are then able to ‘hear’ the size of the room. Several companies make excellent stereo microphones, but I will mention the Neumann USM 69, a condenser microphone which transduces sound electrostatically, and the Brauner VM 1S, a vacuum tube stereo microphone.
Similarly, aided by appropriate mics, we make recordings of the reception area, the main office, the smelly toilets (could one suggest a synesthesia through the recording? – Hearing Colours, Tasting Shapes by Ramachandran & Hubbard is a great read), the Walla of the canteen and its many details; and then using a soundfield microphone system, we capture a multi-dimensional image of the open areas of the premises through ambisonic recording to tape. Using also a binaural/HRTF stereo microphone (such as DSM, SP TFB-2, or MM BSM-8) which is mounted upon a walker’s head or a ‘dummy head’, a mapped walk around the lawns, along the driveway, past trees, by boundary walls, around corners, picking up vehicles driving in, the security guards chattering, film crew instructions and perhaps even Bollywood gossip, the sounds from flats on St Roque Road that is across from the rear end of the complex, to the taxi stand, street sandwich vendor and Patel’s provision stores that are adjoining the entrance will provide incredible spatial information. What other perceptual dimensions are triggered through such audition? Can we extrapolate the composite character of the area? Are there multiple meanings?
Collectively these recordings represent an auditory map of the entire complex and its immediate surroundings. The interesting proposition here would be to collate how listeners imagine the space, how they construct visual images, by listening to these recordings.
Soundwalking and soundscape observation/recording too are quite common as art projects and research in acoustic ecology (here’s an interesting Bristol based cemetery soundwalk; here’s a Blacksea soundwalk recording by the Soundwalk Collective; here’s a Montreal Sound Map and NYsoundmap). The writer here argues for linkages of soundwalking to memory construction and retrieval. There is a long history of research and experimentation in this area, and a work considered canonical now is the 1973 essay of Canadian composer and theorist R Murray Schafer’s The Music of the Environment. There is also his World Soundscape Project research group at Simon Fraser University (see this). The work focuses on studying the complex relationships between people and their sonic environments. John Cage is nearly always invoked here for his thoughts on noise (amongst several other ideas): “Wherever we are, what we mostly hear is noise. When we ignore it, it disturbs us. When we listen to it, we find it fascinating”. Schafer too urges us to listen to the environment as a musical composition, and to find ways to negotiate and ‘claim it’. Amongst the long list of theorists, composers, artists, enthusiasts and others who are enamoured by ideas of sonic conceptualism (Brandon LaBelle’s art practice is interesting), experimental music, indeterminacy and ambient sounds, from Cage, Feldman, Tudor, Stockhausen, La Monte Young and others, there is also Brian Eno and his seminal work Music For Airports - the kind of music that he envisioned as “…theoretically endless, generating new stuff as they go, new combinations.”
This brings me to Electroacoustic Improvisation (EAI) and the last experiment here.
III. Possible Music
Onkyokei is an avant-garde music movement based in Tokyo that emphasizes texture rather than structural composition (see also Japanoise; and tangentially, here’s an interview with Dr Tsunoda, author of The Japanese Brain). The nature of texture can be examined using other sensory cues and descriptors. From a ‘tasty’ sound to a ‘mean and grumpy’ one, attempting to understand the texture of sounds leads us down pretty interesting conceptual pathways. Working on the foundations of the first two experiments here, we extend the idea of sound perception and recording to construct and orchestrate music within the city. The first task at hand would be to ‘find’ instruments. How does one go about this search? Texture is a good start. Location, size and adaptability would be other parameters to be considered.
Could a defunct mill chimney (there are but a few remaining now that stand testimony to the city’s historic textile industry and the worker’s dispossession of rights and land) be converted into a wind instrument? Is it possible to artificially propagate sound across the top using air jets or even from below and dampen the top? Perhaps series of bricks in the structure could be opened/closed mechanically to create sound holes and modulate sound? A pair of even toned coincident mics at the bottom and a directional, lively and rich toned one at the top – Sennheiser 441’s aimed at the bottom, and a lovely classic ribbon like RCA BK 11? David Byrne’s 2009 work Playing The Building comes to mind immediately. Dialed in sounds from around the world arrive to Silo No 5 and interact with the grain storage chambers in the Montreal based Silophone Project.
Can the iconic Air India building be rigged with motion sensor devices based on heterodyne radio signal processing? Akin to principles used in Theremin construction, if such a large building full of office workers going about their business, can be rigged in a way that the diverse, random and indeterminate movements as well as the patterned ones (lifts going up etc) could be recorded, perhaps miked or a direct signal (or a mix of both), we could possibility reorder, ‘mix’ and process the sounds in many interesting ways. Not just via people within the building, but can the building itself be made to ‘sound’? It is possible to imagine multiple ways to intermediate between natural phenomena and the structure – wind, rain, sound reflections, moderated differences in sound pressure (see SPL). A variety of microphone applications can be anticipated here – from contact, to wide-bodied dynamic microphones, parabolic microphones – to address the broad range of frequencies.
From metal sheets on construction sites, hanging from cranes and wobbling in the air, those falling to the ground, a variety of percussive sounds, somewhat tympanic, may be had. The trains of course, provide a steady rhythm, similar to a snare pattern. Roadside sugarcane juicers across the city too provide interesting rhythm patterns. Distinct sounds may be found in their slowing down motion. A whole range of unctuous squeaks and wipes of cloth on glass/Formica tabletops at the various Irani restaurants, the sharp transients, the dull thuds and all the in-betweens of clothes being washed in unison at Dhobi Ghat, the benign bleeps of metal detectors, the attenuated bursts of dental drills, the ‘reverse spool’ like sounds of mechanical sewing machines of the many dressmen on film shoots and the countless tailors in sweat shops – the possibilities of industrial/environmental sounds are endless. There is the water reservoir upon which Joseph Baptista Garden is built and the many temple wishing wells (into which small diaphragm condenser mics, such as the Schoeps Colette modular mic may be introduced) - water columns and air cavities provide yet another range of textural sounds. What requires moderation is the interplay between human endeavour and chance, natural elements and structures/shapes.
How may all of this be organized? A long time measure perhaps, a friend suggests. 13/4. Enough to allow for things to happen, and then maybe even add an extra half beat for happenstance and serendipity.
Close to where I live, there is a small marketplace. Apart from provision stores, roadside meat, fish and vegetable vendors, eating stalls, a playground, there is also a makeshift temple, mosque and the iconic Mt Mary Church. As the sounds of vendors, traffic, buses, shoppers, passers-by, local residents of the housing blocks, kids playing in the park, and the prayers of the faithful emanate, propagate in the humid Bombay air only to eventually dissipate, one can only wonder as to this curious mixing. Once mixed, how can it be undone?
Many thanks to Dr Karen Doherty of SU for discussing several of these ideas (and for the 1994 lab rat experience). Thanks also to curator/essayist Fumiya Sawa, musician Adrian D’Souza and sound designer Arnaud Azzouz for contributing thoughts here.
Posted by Gautam Pemmaraju at 12:15 AM | Permalink