SOUND and SPACE -issues of design -19

Post 661 -by Gautam Shah


Philharmonie im Gasteig, München Wikipedia Image by Andreas Praefcke

A space is perceived through three main senses -seeing, hearing and touching. The three senses mutually compensate and reinforce the perception. The perception occurs through coordinated stereo perception of sensory elements like two eyes and ears, and spatially distributed elements for touch. All three senses, scale the extent and depth of space. Physiologically, hearing diminishes with distance; seeing fades with reduction of illumination and touch becomes ineffective with the loss of tangency. Psychologically, however, the all three experiences remain associated with places, spaces, seasons, moods and people. The three senses format the perception of space. The space experience gets reinforced by the lingering effects like echoes, reverberation, and afterimages.

A group of musicians; representing the sense of hearing

Sound dwells in two distinct entities: space and time. The realm of a sound originator -the speaker, a singer, perceives substantial sound from the same space –the vicinity. The world of listeners is spatially separated and distinct, but has slight time delay. This duality is negotiated with some form of calibrations to arrive at common perception. The musicians and speakers tune and improvise once inside a space and begin to deliver. Oftentimes, we shout in to the telephone, believing the reception at the other end is equally bad. Similarly pauses in speech or music by the sound originator, if occupied by other ’disturbances’ (echoes, reverberated sounds, background noises, local absorption), the equation between the listener and sound maker fails. This is one of the reasons why it is nearly impossible to faithfully record a real out of the door profile of sound. What we listen in a place is ‘a convolution between the original sound and response of the room.


Sound is a spatial entity. Sound-spaces are associated with shapes, sizes, materials and memories. In outdoor unbounded spaces the environmental elements like terrain, components of atmosphere and vegetation are modulators of the sound. In the long run these elements format the quality of speech and singing of people of the locality are affected by the surroundings. In ethnic societies the diction gets reinforced, whereas with migrants, it persists in traces for several generations.

The sense of Hearing in ART

The sound is also a temporal phenomenon, a dynamic happening. The sound-happening persist for a very long time and spreads through cutouts, chowks, openings like doors and windows, gaps, cleavages, holes and cracks. Sounds have an eerie feeling in empty spaces due to unpredictable time delays, amplification and directionality. The time-sound response in such spaces fudges the scale and materials. Cluttered spaces have loss of detail due to subjugation of background noises. The connect with external noises provide eventual reference to the personal domain.


Sound in architecture is heard through the physical presence and sensitivity. Sound induces emotional connect and sensual responses. Inside or outside, materials, scale, memory and familiarity, all create a ‘sense of sound. The sound acquires a personal identity. Sound is both a ‘tangible and intangible sensational atmospheric quality’. It allows the individual to physically hear, as well as feel and sense the characteristics present in architecture. So, Sound like the illumination helps in cognition of the spatial information, and these processes occur concurrently and reinforcing each other. Hearing and seeingenable us to communicate, to orient ourselves, and to recognize danger.

Familiar Spaces Hunter's home, by Henry Voordecker

Peter Zumthor outlines that, “Interiors are like large instruments, collecting sound, amplifying it, transmitting it elsewhere. That has to do with the shape peculiar to each room and with the surface of materials they contain, and the way those materials have been applied.” (Atmospheres, p. 29).

Peter Zumthor

The simultaneity of images and sounds is most important aspect of communication for cinema, advertisements, multi-media presentations, games, products, telephony etc. to construct or mask the reality. Typically pressing buttons needs concurrency of tactile, audio, and visual experiences, and these may not be real or life-like but one that arouses satisfaction of an action happening. In certain aural-visual environments like games, films, TV programmes, telephony, medical examination equipments, the visual data is too consistent, but is variegated by addition of sounds as feedback or feed forward clues. Similarly addition of beats or predictable rhythms adds measurable familiarity.

Marionettes from the Swedish Cottage Marionette Theatre, New York, USA production of Cinderella Samba

Sound is transitory, so the rate of fading and its directionality, as ‘aural impressions’ must become elements of design. But rarely architectural spaces are created for the ‘sound-scape’. Many sound-space installations are created, some in bounded and many in open areas. Bounded spaces are handled with uncertain volumetric maneuvers and surface manipulations’, or with gadgetry to alter the quality of sound production. Open spaces are more scary as the volume is not maneuverable and surfaces beyond the echo-reverberation range. Here too, the gadgetry is used to alter the quality of sound, but effects are sporadic.

Instrument Musical Clarinet Sound Music

A street or neighbourhood reveals itself more at night. The sounds impinging into the interior space with little variations of illumination (of moon light, street light glow, and vehicles head lights) bring forward the depth of the spatial surroundings. But human settlements are designed for visual and aural spaces of day-time only. The public spaces turn unfamiliar (and unfriendly) at night. At night the aural space seems more holistic then visual space, because sound seems to transcend many obstacles or barriers.

Lonely Place 2


This is the 19 th article of 20 topics series on ISSUES for DESIGN





Post 270 – by Gautam Shah



Sound and Noise, are two irritant aspects of a space design. Both are hard to define and tackle. Clients, Designers, and subject experts, are never fully satisfied by the strategy of a solution finding or results.

In everyday life we use both the terms with different but subjective associations, though sound has more positive affiliation then what noise implies. Noise is a sound, of a type, or rather of a context. Noises are of many types, and have unclear bearing compared to sound that has specificity of quality and origin. The past associations of the perceiver are major determinants, whether a sound is considered as noise or not. Noise and sound are also differentiated on scale of aesthetic awareness. Familiarity or clearer perception can translate an aspect of noise into a sensible experience -the sound.


The term noise is derived from the Latin word nausea = sea sickness, whereas the word sound derives from soun (middle English), son (Anglo-French), sun (Latin) or sonus > sonare > sound.

Noise, even of regular composition if loud, in the short term disturbs people as it makes it difficult to hear wanted sounds, or breaks their concentration. In physics and science of acoustics, noise is an unwanted random rider to a signal, that generates hiss or static.

Noise is excessive, unpleasant, annoying and unwanted sound which results in annoyance, and in the longer term loss of hearing. Hearing impairment (presbycusis) occurs with age, but noise can hasten it. Noise causes changes in the body immune system, stress, hypertension, ischemic heart disease, tinnitus and vaso-constriction. Noise exposure also creates sleep disturbance increases workplace accidents, aggressiveness and antisocial behaviour.


Sound, though desirable than Noise, can also be annoying, due to its loudness, perceptive clarity of detail, inability to localize its source, reverberations, unauthorized infiltration into protected spaces, and in substantial absence of it.


In Space Design the Noise and Sound control mechanisms overlap. Noise mitigation strategies often impact, in suppressing the desirable sounds, removing the background noises, and necessary reverberations that are often required to remove feeling of loneliness and perception of space size, form and other sensorial definitions.

The areas where noise and sound control management become important design issue are: Road, railway and aircraft corridors, cabins of transport operators, industrial plants with impact operations such as forging, transport terminals, public gathering places, underground or covered parking lots, hospitals, sanctimonious locations and buildings. Some spaces like conference halls, auditorium, meeting rooms, concert halls, entertainment and social venues, dining areas, audio recording rooms also need similar attention.


Noise and sound management techniques include: Insulation prevents transmission of noise or sound across spaces and barriers, by providing appropriate mass and surfaces. Absorption is a quality of mass to convert the sound energy into (micro level) heat within the material. Vibration damping is required to remove vibratory energy getting transmitted in thin body (sheets, tout wires) materials and thereby generate sounds. Examples are air craft and automobile bodies and very thin shell structures or roofs. It can be achieved by isolating vibratory body by including breaks or absorbent elements. Vibration causing sound waves in air, hydro-acoustic waves in water, and stresses in solid matter.


Complete sound absorption has very important roles in specialty spaces, where a sound, only from a designated source is valued. It means the perceiver, person or device, gets sound without any spatial modifications (reverberations). This is required in a recording studio, sound calibration labs, and non detectable stealth vehicles like air-crafts or submarines.


The traditional sound and noise handling techniques are based on materials sciences, shape or form configurations, and element siting. These traditional methods required extensive interventions in space, such as partitions, ceilings, floor treatments. These elements use absorbent or insulation materials and techniques that are highly vulnerable to fire and have high ecological concerns. The sound and noise control elements reduced the daylight into deeper spaces and reduced the outdoor viewing. For a unified space configuration, reduction of barricading and intervening elements is very important, which can occur by adopting sound masking technologies.

Sound masking is opposite of soundproofing, as it is an active addition of noise to a space, to counter certain sounds. It is like in an Interior Space where to reduce the glare from an opening, one can either place a curtain on the opening, or put on additional illumination in the room. Sound insulation works like the former and sound masking like the later method.

11 transport_disney_parade_sound_truck_megaphone_noise-1030602.jpg!d

Sound masking is addition of natural or artificial sound into a space to suppress the effects of unwanted sound. It is done with specially designed speakers installation to add ‘low level’ sounds over the existing sounds in the space. It reduces the chances of imperceptible sounds coming to a personal field, and affect the concentration or add to distraction. Additional sounds reduce or eliminate the pervading feeling of pre-existing sounds to make living areas more audio-comfortable.



Post -by Gautam Shah


Singing in a bathroom sounds lively, but only to the person in the bathroom, because the reverberated sound seems to be richer, and fuller. A bathroom also offers a very private space for uninhibited behaviour.

Small rooms like a bathroom have small sizes, and smaller volumes. Such spaces include an inner sanctorum of temples, confession booths, personal prayer rooms, private offices kitchens, study rooms, store rooms and telephone kiosks. These rooms are used for personal meditation, prayers, recitation, singing, self-talk or person to person (one to one) voice communication (directly or through telephony).

There are two major qualitative characteristics of these spaces: Smaller size resulting in Smaller volume, and the Nature of furnishings. A bathroom like spaces are bereft of any soft surfaces, whereas study room like spaces are over furnished. But all small spaces allow multiple reflections from architectural boundaries and enrich the sound of one’s voice.

A study room made ‘cozy’ with heavy furnishings, draperies, thick walls become a sound absorbent environment. Here the richness of the bounced or reflected sound is lost. The highly isolated space cuts-off the low frequency ‘interference’ of outside noises like traffic, wind, rustles of the leaves, etc. The absence of background noises does not mask the internal low frequency noises of the room. As a result sounds our own body movement, rustling sounds of clothes or book pages, fan or air conditioner’s hiss etc. are over emphasized and become disturbing.


The acoustical properties of small rooms differ considerably from that of large rooms, such as the auditoriums, concert halls, cathedrals, lecture halls, etc.

● In a large room, first-arrival times of the early reflected sound are typically on the order of # 50-80 ms after the direct sound.

● For small rooms, the first-arrival times of the early reflected sound are # few ms after the direct sound.


For heavily furnished ‘Home rooms’ the sound absorption properties of the room often are significantly higher than in large rooms. Small rooms often provide the ‘acoustic intimacy’ but do not have ‘acoustic grandeur’ of very large spaces. Large rooms have distinctive reflections which help us comprehend our location, the direction and distance of objects etc. In large rooms there are likely to be few surfaces that are horizontally askew, vertically inclined and surface quality wise irregular so some blurring of the reflections is inevitable.

In a space original sound travels more or less straight to the listener whereas the reflected sound must travel towards a boundary and then get bounced back to the listener. Such delayed reflections heard along with the original source sound are the cause of echoes.


Reflections often obscure the true source of a sound and reduce intelligibility. This effect is more pronounced in small rooms than larger ones because the walls are closer together and so the reflections are stronger. However, the strength of the reflections also depends on the density of the walls, with rigid walls reflecting more and to lower the frequencies. Indeed, the worst environment for a home studio is a basement because cement walls are more rigid than partition or thin body walls. Thick walls around small space rooms improve the acoustic isolation but thin partitions allow lower frequencies to pass through to get absorbed within the body or expended in vibrating the thin body mass.

669px-Jan_Vermeer_van_Delft_014In the natural world without walls or ceilings, the First Significant Reflection will always come from the ground. We subconsciously use the FSR to determine distance from an object. For example a person speaking to a listener from 2′ distance, the initial sound will arrive about 2ms while the FSR will be about 11ms. Thus effective FSR is 9ms (11-2=9ms) to the listener. If the speaker is 10′ away, the FSR will be about 5ms from the listener’s perspective.

Size and Shape of a room affects the quality of sound in a room. ‘In a room with parallel walls (almost all rooms), the sound gets a caught bouncing back and forth between the walls. Some sound waves are cancelled by their own reflections while others are reinforced’. However, in a room with slightly askew walls can drastically reduce the redundant reflections between walls. Ancient Greeks found that rooms with the ratios of 2.62: 1.62:1 sounded universally good.


Regent Park audience Wikipedia Image by TomIAnderson

One of the famous sermons from Jesus was made at the bottom of a hill while the audience was on higher ground Here Jesus was addressing a very large audience from a Low position. Since this was in the morning, the audience was in the optimal position to hear and see him speak, The hill helped capture the speech and block out extraneous noise.  ( This is as per the Literary description, Paintings illustrate superior-higher position for the Christ).



Postby Gautam Shah



Sounds are something we listen to, but more effective is the absence of sound that is being enforced through the silent interludes. Some silent interludes are intentionally created by the musicians, singers or the speakers due to hesitation, stuttering, or self-correction. Some pauses reinforce the delivery, while allowing time for the absorption of the message or information.


In 1952, Cage, a musician composed a piece that became his best-known and most controversial creation: 4’33”. The score instructs the performer not to play the instrument during the entire duration of the piece—four minutes, thirty-three seconds -and is meant to be perceived as consisting of the sounds of the environment that the listeners hear while it is performed. ( )

Ohn Cage 4.33

‘Music inherently depends on silence in some form or another to distinguish other periods of sound and allow dynamics, melodies and rhythms to have greater impact. For example, most music scores features rests denoting periods of silence. In addition, silence in music can be seen as a time for contemplation to reflect on the piece. The audience feels the effects of the previous notes and can reflect on that moment intentionally. Silence doesn’t hinder musical excellence but can enhance the sounds of instruments and vocals within the piece’.


Whatever type of environment, enclosed or open, one is required to speak, the sound will be absorbed, reflected, or diffracted. The absorption occurs: in air and in materials. Sound as energy is lost in air due to the friction with air molecules. Moving or hot air with agile molecules will increase the absorption. Sound energy is lost in materials through its conversion into heat energy. Sound energy may be transmitted through induction of vibration in thin body materials.


Speakers and musician also know the craft of exploiting the effects of sound reverberation in a space. Reverberation is ‘lingering’ of sound after the main source stops, but its reflections continue within a space with gradual decrease in amplitude, until they can no longer be heard. The decrease in amplitude or gradual decay of sound occurs due to absorption in materials that form the spatial boundaries. The length of this sound decay is reverberation time. Reverberation, if excessive makes the sound becomes muddy or garbled.

Retuning Instrumernt

The time taken for a sound pressure level to diminish 1/1000 of its original level (-60dB), is called the reverberation time. It has major effect on the quality and intelligibility of speech. Some reverberation is needed to give a body and fullness to music. Ideal reverberation time depends on the type of music but lies between 1.75 and 2.5 seconds. Speech needs much less time for clarity. However, a little reverberation improves the subjective effect, as for example in sermons or similar addresses. For speech reverberation between 0.5 to 0.75 seconds could be adequate.

Most hard surfaces like concrete, stone, plastered masonry absorbs very little sound and are called sound reflective surfaces. Porous materials absorb the sound energy, whereas thin body materials convert the sound energy into a vibration.


Reverberation is not the same in all sections of a hall or for all frequencies. This is reason why acoustics’ quality differs from hall to hall and from seat to seat. Modifications are needed for different types of music by introducing absorbent panels and resonators or reflectors at various points. Sound is Energy, once created in a closed space, it will continue to spread till it is transmitted through the edge barriers or transforms itself into some thing else -like heat. When this is poor the sound is audible much later. A reasonable fast music or speaker would have delivered several notes or syllables.

Some spaces have long reverberation times at low frequencies, thus imparting a warm sonorous tone to the music, while others have longer treble times giving a more brilliant effect. Usually a balance is sought. Most halls with PA systems have longer reverberation times than required for speech resulting in loss of clarity. This can be slightly improved by use of column speakers angled towards the audience and away from the reflective walls of the hall. One of the most effective way is to provide a heavy curtain across the rear of the stage. This could be drawn back for live musical events to provide longer reverberation time.



Post -by Gautam Shah

The tonal quality of spoken language or sound is determined by many factors like social history and ethnic affinity. It is also formed by dominant building forms, materials and the physical environment factors like terrain, topography, (plains, coastal, valleys, lake fronts, forest, deserts). The quality of speech-sound is acutely affected by the environment one dwells in or aspires to be with.


There is a saying in Gujarat, India that every 20/25 km Speech varies. Such ‘Socio-linguistics’, can happen syntactically, lexically, and phonologically. The Phonology relates to the systems of phonemes or the organization of sounds in a language.


People (fishermen) who stay close to a sea coast are affected by the continuous splashing sound of waves. Similarly villagers staying in a valley often bear the echoing effect of the mountain range, whereas in plain desert land there is complete absence of bouncing sounds. People living on a very busy-noisy street have to talk louder and that habit remains with them for a very long time.


True colour of human speech comes about by intra vowel-consonants pauses, vowel and consonant utterance lengths and preferred frequency combinations, intra word pauses, phrasing, etc. When a language is spoken in different terrains each, creates its own variants. Human speech variants develop according to the environment one resides, and specifically how one listens to own speech sounds. This is perhaps the reason why children with deficient hearing capacity often have poor speech formation.


It is also true that people tend to accept the speech sound they can make as the perfect one, which may not be true. Teachers have better speech quality, as they have more opportunities to improvise. Similarly an American child or for that matter any child of a well to do family, bred in media culture is better attuned to a style of talking that is correct for good projection. Next generation of children are going to be more articulate than their parents or other non media children.


Speech intelligibility is a function of space. Space not only defines how the speech will be listened to, but also how the speaker or musician will improvise the output.


In Indian classical music concerts (vocal and instrumental) we have seen masters tuning the musical instruments, drums on stage, in front of the audience. This is often irritating to many, but in reality the musician is attuning the sound for that space and environment (moisture, temperature and air movement currents). The Alap in Indian music, the first rendering that is without the drum beats, is also attuning for the space and environment. Most Western concerts or Pop singers spend hours on the ground testing position of the speakers, their location and pitch of a sound etc. to attune to the site conditions.


Most experienced speakers and stage actors have the capacity to instantly modulate their output according to the quality of space. For example, if the background noise is high, the speaker will raise the voice and change the tonal quality (change the range of frequency to over come masking) or if there is a longer reverberation, the pauses between words are widened. Speakers also face the section of crowd they want the message to sink in. In group discussions, an experienced person automatically shifts to a ‘sound’ advantageous position. Seasoned actors during the rehearsals pick the nuances of stage positions and body posture to deliver an effective dialogue.


Effective sound delivery is closely related to how the speaker is perceived. For example on non visual space like the Radio or telephone a straight into the mike creates a steady delivery of sound, but a moving speaker (or the mike) carries the impression of a non-sincere person. Most of the TV anchors are taught to speak without moving their head or body. There was a time when the surroundings or space mattered a lot on the quality of Sound being carried, however, today the microphones can eliminate the background noise and also do some degree of micro balancing to eliminate the differences caused by shifting speaker or singer.


SOUND -as we listen

Postby Gautam Shah


SOUND is sensorial perception received mainly through the Ears, but often through the Skin of the body. The ears are on either side of the body, and so are able to distinguish the sound from left or right fields. The ears are able to distinguish pitch and intensity of the sound and thereby roughly determine the source, its distance and the nature of medium through which the sound has arrived.


In technical sense Sound is caused by the Mechanical disturbance in a solid, liquid or gaseous materials. These materials have varying degree of Elasticity to act as the sound transmitting medium. The vibrating objects could be the vocal cords of a person, string and sound board of a guitar or violin, tines of a tuning fork, or the diaphragm of a radio speaker. Music is formed of one fundamental frequency, and several other integral multiples of this basic frequency, called harmonics. A pure Tone of sound, composed of only one frequency is one that is produced by a striking fork.


Sound producing or vocal organs are many such as: lungs, windpipe, throat, larynx, nose and mouth “The vocal organs –are primarily for breathing and eating. The lungs act as bellows. The vocal cords or folds of the larynx vibrate as double reeds. The cavities of the throat, nasal sinuses, and mouth act as resonating chambers, with the size of the mouth cavity varied by jaw movement.”

Human voice is more versatile than any other musical instrument. Sarangi (Indian musical instrument which has guts -instead of wires, and played with a bow, its markers are created by pushing the gut upward over the fingers) emulates sounds that are closer to human voice.


Vibratory energy that is perceived by the human ear or the audible sound is termed as audio or sonic. Audible range of frequencies for a normal young person is 20 Hz to 20000 Hz (1 Hertz = 1 vibration/second). Very low frequency (infra sound lower then 20Hz) or very high frequency (ultra sound beyond 20000Hz) are not perceived by the human ear. Actual audio capacity of an individual person varies a lot. Intelligible human speech occurs in the range of 600 Hz and 4000 Hz.

Caissons_grave_DSC_5563ECThe ears of children respond to very high frequency sounds which by adulthood narrows to about 15-15000 Hz. The loss of hearing in adolescence, approximately 80 Hz every six months, becomes noticeable years later. An aged person may not hear high frequency sounds such as ticking of a watch or certain high frequency consonant sounds.

EdisonLaboratoryMusicRoom1905smHuman ear or mind has enormous capacity to discriminate and to extract the required information from the background noise and signals. The Noise -the unwanted range of Sound is below 200 Hz. However it cannot separate out sounds that are close either in frequency or in time. A human ear has greatest sensitivity between 100-4000 Hz.


General room noise masks the traffic noise, making it less noticeable, or the traffic noise may mask the conversation taking place in the room. It often happens that in an attempt to reduce the external sound penetration through efficient insulation, enhances the internally occurring noises. Inversely by eliminating all the internal noises one may enhance the effect of sounds arriving from outside.

A modern good quality PA system should be capable of 100 Hz to 6000 Hz and preferably 10000 Hz. For music the PA system should be 80 Hz to 10000 Hz and up to 15000 Hz for high quality theatre type of installation. Some sound equipments include loudness control by attempting a degree of compensation by boosting bass and possibly treble at low listening levels.


This means that if a sound is reproduced at a higher level than at which it was recorded, then the low frequencies will become relatively louder (speech will sound boomy). If it is reproduced at a lower level then it will sound `thin’ and lack bass (orchestra reproduced at a small room level).







Most experienced speakers, stage actors and musicians (vocal and instrument players) have an innate or learned capacity to improvise their output immediately on encountering a new space. They readjust -their output according to the audio response from the nature of space.


The Nature of Space is determined by several objective and Subjective factors.


The objective factors are the size, scale, shape and form (hard vs soft surfaces) of the architectural space. Other objective factors include degree of echoes or reverberation in the space, quality of public address system, location and direction of the speaker or musician, etc. The occupancy or crowding in the space, and the nature of garments, furniture and furnishings also affects the perception of sound. The background noise seeping to the speaker or performer’s area and the audience, or to the listener (in small gatherings) could be very different. This means that a performer may not perceive the audience or listener’s environment. Only way to sense this is through the recognition of behavioural responses. Experienced speaker or performer raises the voice and change the tonal quality, and if there is a longer reverberation, the pauses are widened and delivery stretched in time.


Speaker or performer sense the space and focus the address to that part of the audience, where Sound delivery is perceived to be inadequate. The performer use enlarged body language and dress movements to supplement the Sound.