SOUND and SMALL SPACES

Post 128 - by Gautam Shah
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Acoustical properties of small rooms differ considerably from large spaces such as the auditoriums, concert halls, cathedrals, lecture halls, hospital wards, etc. Some of the most important elements that differentiate the quality of sounds are volume and depth or width of the space. In an average space original sound travels more or less straight to the listener, whereas the reflected sound must travel towards an edge or boundary, and then get bounced back to the listener. Such delayed reflections heard along with the original source sound cause of enrichment of sound and in some cases irritant echoes.

Size and Shape of a room affect the sound perception 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’. Room with slightly askew walls, drastically reduces the redundant reflections between walls. Ancient Greeks found that rooms with the ratios of 2.62: 1.62:1 sounded universally good.

When an original audio source is recognized, one turns the head to that source. Head turning helps in tuning the source and also for eyes to locate the original source. Such audio source location and its visual perception create a psychological sense of adequacy. In very large volume spaces the original sound may become feeble at the peripheral areas, allowing a surface bounced sounds to dominate the listening.

•  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.

 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 in strength, but not delayed enough to produce sonority. The strength of the reflections depends on the density and rigidity of the edge surfaces. 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.

Felix Mendelssohn's Leipzig study

In 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.

 

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.

Singing for self > Miranda sings Wikipedia pic Attribution: Gage Skidmore

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).

 

Beyond the two qualitative characteristics of small spaces such as smaller size and smaller volume, it is the Nature of furnishings that affects the feel for sound. A bathroom like space is bereft of any soft surfaces, whereas study rooms are over furnished to make them cozy. Heavy furnishings, draperies, thick walls form a sound absorbent environment. Here the richness of the reflected sound is lost.

 

Small spaces allow multiple reflections from architectural boundaries and enrich the sound of one's voice. 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.

Chamber music

A highly isolated space (cut off through high insulation) cuts-off the low frequency ‘interference’ of outside noises like traffic, wind, rustles of the leaves, etc. The internal low frequency noises of the room cannot be suppressed in absence of absence of background noises. 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.

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DOCUMENTING PROJECTS

Documenting Projects > Post 127 ⇒  by Gautam Shah

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Projects evolve through several levels of activities, by Financial advisers, Project consultants, and Designers. These project convening agencies take into consideration feedback or feed-forward of various stack holders, actual or likely users-owners, sponsors, regulators, fabricators, vendors and servicing agencies. Each of the project convening agencies need to deliver their products to others. As a result the transfer is formal and well documented. The project documents do not need to be collated, as one document becomes the basis of subsequent one. Each of the project convening agencies does not blindly follow the content, but recheck it. The project, as it passes through multiple agencies matures well.

● Defining the project objectives (concepts, policy, analysis, design, quality parameters, concerns)

● Defining the means and methods of achieving the objectives (assessing, choosing)

● Planning the resources (estimating, procuring, allocating)

● Time and Space scheduling

● Delineating the project into various categories, components and tasks

● Organizing and foreseeing the project actualization

● Setting evaluation and preview methodologies

● Assessing, controlling and providing for the risks

● Implementing a feed-forward and feedback system for project execution and operations phases.

These aspects (as listed here above) are projected differently by different consultants (project convening agencies) as per their area of intervention and presented at different stages of a project. Designing agency is last but one to intervene in the project. The last ones to step in are the project operations agencies. But it is the design agency that acts as the de-facto coordinating entity.

Design agency collates the different documents are mechanisms through the deliverable product -the design. However, where owners, conveners, planners, designers, vendors, executioners, supervisors and operators converge, the documentation may get obliterated due to in-distinctive roles. These happen with organizations, who own, execute and operate a project as single entity.

 

Some of the Project documents created by the involved parties are:

▫ Project Charter, Project Profile Report, Business case model, Feasibility Study, Scope Statement, Terms of reference, Project Management Plan, Project Initiation Document

▫ Work Breakdown Structure, Assignments, Task lists, Schedules,

▫ Accommodation of Alterations, Change Control Plan,

▫ Communication Plans, Network structure, Reportage system, notifications,

▫ Risk Register, Risk probabilities, Risk extent, Risk Management Plan (avoidance, mitigation, factors of safety, margins), Risk compensations

▫ Governance Model, Administrative strategies

▫ Export - Import / Entry- exit Logs

▫ Actions history Lists

▫ Resource Management Plan

▫ Project Schedules, Targets

▫ Status Reports

▫ Responsibility - authority structure

Such documents once had restricted access and available to only relevant project members or owners. However, with modern quality management systems, it is desirable to make them available to all project participants and stack holders. Such documents are hosted on shared resources like web-pages.

 

Public projects, Historically long lasting (monumental) projects and projects with large scale risks and other difficult to predict liabilities are not only well documented through all stages of the Project Life Cycle but such documents are desirably made as open documents for public scrutiny..

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