C haptEr 9 design Environments and systems
370
includes many of the topics we’ve discussed but is broader in scope.
The broad field has evolved into a number of subdisciplines, albeit
all founded on similar scientific principles. Hence we have architectural acoustics, which deals with the study of the behavior of
sound in architectural spaces (auditoriums, concert halls, commercial establishments, and the like) and the way sound and building
design parameters interact. Other fields include aeroacoustics, bioacoustics (the use of sound by animals), biomedical acoustics (the
use of sound for medical purposes, as in ultrasound applications),
aeroacoustics, electroacoustics, and many others. The focus in this
section, however, is on acoustic strategies in relation to building
spaces and products.
A typical acoustical design objective is to create spaces that enhance
the audibility or clarity of speech or music, or, as is the case in
some concert halls, to enhance the qualities of performances.
These latter objectives are particularly complex because of the
normal need to have good sound qualities, not at just one point
but throughout the spaces occupied by listeners. Sound qualities
will be inherently different from location to location throughout a space because direct and indirect sound paths to various
locations will inherently have differing directions, travel distances,
and numbers and types of reflections off surfaces that have differing reflective qualities and different absorptions. The shape of the
enclosing surface and placement of surfaces with differing properties are consequently clearly important design variables. In building design, shapes cannot also be simply optimized for sound,
however, because of other complicating needs for viewing, egress,
and the like. The complications of designing these spatial environments for acoustical performance were described at length in
Section 3.5 in relation to a concert hall. Other kinds of building
spaces, such as lecture halls, are also particularly important from
an acoustic design perspective.
The issues involved in the acoustic design of these kinds of spaces
are complex because it is necessary to model not only the way
sounds interact with properties of surrounding materials but the
overall characteristics of the space itself and the way sounds are
disseminated through it. When a sound made by a person or an
instrument is generated in a room, sound waves travel outward
from the source and reach a listener, both by a direct path and
by reflections. A listener sitting very near a stage in an outdoor
setting will hear the sound of a musical instrument essentially as
the player produced it. The sounds typically are not persistent.
Within an enclosed setting such as a room, however, the listener
370
includes many of the topics we’ve discussed but is broader in scope.
The broad field has evolved into a number of subdisciplines, albeit
all founded on similar scientific principles. Hence we have architectural acoustics, which deals with the study of the behavior of
sound in architectural spaces (auditoriums, concert halls, commercial establishments, and the like) and the way sound and building
design parameters interact. Other fields include aeroacoustics, bioacoustics (the use of sound by animals), biomedical acoustics (the
use of sound for medical purposes, as in ultrasound applications),
aeroacoustics, electroacoustics, and many others. The focus in this
section, however, is on acoustic strategies in relation to building
spaces and products.
A typical acoustical design objective is to create spaces that enhance
the audibility or clarity of speech or music, or, as is the case in
some concert halls, to enhance the qualities of performances.
These latter objectives are particularly complex because of the
normal need to have good sound qualities, not at just one point
but throughout the spaces occupied by listeners. Sound qualities
will be inherently different from location to location throughout a space because direct and indirect sound paths to various
locations will inherently have differing directions, travel distances,
and numbers and types of reflections off surfaces that have differing reflective qualities and different absorptions. The shape of the
enclosing surface and placement of surfaces with differing properties are consequently clearly important design variables. In building design, shapes cannot also be simply optimized for sound,
however, because of other complicating needs for viewing, egress,
and the like. The complications of designing these spatial environments for acoustical performance were described at length in
Section 3.5 in relation to a concert hall. Other kinds of building
spaces, such as lecture halls, are also particularly important from
an acoustic design perspective.
The issues involved in the acoustic design of these kinds of spaces
are complex because it is necessary to model not only the way
sounds interact with properties of surrounding materials but the
overall characteristics of the space itself and the way sounds are
disseminated through it. When a sound made by a person or an
instrument is generated in a room, sound waves travel outward
from the source and reach a listener, both by a direct path and
by reflections. A listener sitting very near a stage in an outdoor
setting will hear the sound of a musical instrument essentially as
the player produced it. The sounds typically are not persistent.
Within an enclosed setting such as a room, however, the listener