BU3 Midterm Reviewer PDF

BU3 MIDTERM REVIEWER architectural acoustics – study of sound in homes and other bldgs., design of those structures for optimal acoustic perf, including control of sound, transmission throughout the bldg, maintaining conditions for good speech in...

BU3 MIDTERM REVIEWER architectural acoustics – study of sound in homes and other bldgs., design of those structures for optimal acoustic perf, including control of sound, transmission throughout the bldg, maintaining conditions for good speech intelligibility, maintaining sound isolation for speech privacy acoustic/sound attenuation – when the intensity of a sound diminishes as it passes through a medium HVAC background noise – noise generated by bldg’s heating, vent, and aircon day-night average sound level (DNL) – sound level in a space averaged 24hrs, 10db added to all sound between 10pm and 7am before the avg is done, avg level is usually greater than true energy av level over the day impact sounds (impact isolation class – IIC) – airborne sound or noise arising from the impact of an object making direct contact with a surface noise level reduction (NLR) – amount of attenuation provided by construction to reduce the noise level on the other side than the source noise pollution – unwanted sounds that can have a negative impact on health and quality of environment noise reduction coefficient – is a rating of how much sound an acoustic surface or material can absorb decibel – described how loud a sound is and it is defined as logarithmic of two power quantities 20 micropascals – lowest pressure heard by the human ear 3 dB – human ear is not able to detect a difference of --- in sound level 65 db – avg classroom noise level 50 db – ideal learning space level 8 hours – no. of hours of exposure to 90db traffic noise can cause hearing damage 15 mins – exposure to 120db music can cause hearing loss outdoor-indoor transmission class/OITC sound rating – provides a single number rating for roofs, facades, and façade elements that are subjected to transportation noises, higher number better noise isolation, 80 to 4000 hertz reverberation – sound that reflects around inside a room even after the source has become silent until the sound loses energy, less of this means easier to understand speech in a given space reverberation time – time it takes for a sound to decay 60db after the source has become silent sound isolation – aka noise isolation, sound blocking, ability to block sound transmission from 1 room to another by separating or decoupling assembly materials to stop the transfer of sound energy sound masking – 1 sound, often intentional, introduced into an environment to make another undesirable sound less audible sound pressure level (SPL) – measure of sound’s pressure relative to the pressure around it; quiet sound produces waves with small pressures sound transmission class/STC rating – 1 of the standard metrics that quantifies an assembly’s ability to decrease airborne sound transfer between rooms soundproofing – general term used to describe reducing sound pressure between a source and receiver speech intelligibility – ability to hear and understand conversation, sound power and directivity of the speaker, bg noise level, sound attenuation between source and receiver speech privacy – inability to understand someone else’s speech – opposite of speech intelligibility sound – is a vibration in an elastic medium such as air water bldg materials earth sound energy – progresses in atmospheric pressure and travel a great distance wavelength of sound – distance of a sound wave traveling during 1 cycle of vibration, distance between adjacent regions where identical conditions of particle displacement occur velocity of sound – speed at which sound travels, primarily depends on the elasticity and density of the medium 1130 ft/s – in air, at normal temp and atmospheric pressure the velocity of sound is ---- 16000 ft/s – along steel pipes and duct walls 12000 ft/s – speed of sound in concrete propagation of sound – sound is generated in a place, it can move or spread in all direction by air, all directions like a person blowing up a balloon with his mouth diffraction of sound – bending of sound waves due to obstacles, causes decreasing of frequency, loudness, and pitch hearing sensitivity/sensitivity of hearing – ability of understanding or listening of sound is called, depends up on person eardrum, intensity of sound, type of sound tone, distance between source and listener, climatic conditions PHYSICAL CHARACTER OF SOUND 1. FREQUENCY 2. LOUDNESS/INTENSITY 3. QUALITY/TIMBRE frequency/pitch – number of cycle or pressure vibrations produced by a body in unit of time, greater number means higher pitch loudness/intensity – flow of wave energy crossing per unit time through unit area, measured in dB quality/timber/timbre – quality of musical note, one of the importance characters of sound allows the ear to differentiate between tones produced by different instruments when the sound waves are identical in aptitude and frequency amplitude/volume – characteristic of sound waves that humans perceive as volume, corresponds to the distance that air molecules move back and forth as sound wave passes through them measurement of sound – sound can measure in terms of pressure level or decibel decibel – used as convent unit to measure the magnitude of sound waves – transfer energy through solid, liquids, gases, vacuums, generating transverse or longitudinal waves based on particle vibration sound wave – disturbance pattern resulting from energy movement through a medium like air or water as it propagates away from the source, generated by object vibrations, create pressure waves, disrupt surrounding medium’s particles TWO TYPES OF WAVES 1. LONGITUDINAL WAVES 2. TRANSVERSE WAVES longitudinal waves – sound wave that vibrates in the same direction as all particles in a medium, such as liquid, gas, solid, experience compressions and rarefactions sound waves – example of longi waves, traveling through air/water, energy released when something vibrates, carried by the air, move parallel speaker – vibrational sound energy transfer to air molecules causing them to move forward, closer, back to their orig position drum – skin vibrates, causing air particles to vibrate around it P waves – aka primary earthquake waves, example of longi waves, push and pull on earth, rock-like soundwaves, can pass through solid, liquid, gas transverse waves – move perpendicular to the wave’s direction, ocean waves, ripples on lake frequency – describes number of waves that pass a fixed place in a given amount of time hertz – unit of frequency particle velocity – velocity with which particles of the medium vibrate in order to transfer the energy in form of a wave spectrum analyzer – work by using a microphone to convert he sound wave into an electrical signal speed of sound – varies greatly depending upon the medium, determined by combination of the medium’s rigidity and density, more rigid = faster, greater density = slower low – speed of sound in air is ----, because air is compressible wavelength – distance between 2 peaks of a soundwave, related to frequency because the lower the frequency of the wave, the longer the ---- nomogram – gives the wavelength corresponding to a particular frequency power – energy per unit time, sound source has an associated sound ----- output watts – unit of power intensity – power per unit area, energy flow in space, sound intensity is related to sound pressure pressure – force per unit area, acoustic pressure is what drives motion of the eardrum COMMON ELEMENTS OF ANY ACOUSTICAL SITUATION SOUND SOURCE – no need to consider the path or recipient’s locations if source is controlled SOUND TRANSMISSION PATH – if sound can be controlled between source and listeners, then listeners location are irrelevant RECEIVER OF THE SOUND – sound reception can be influenced, which is not usually an architectural concern TWO SOURCES OF SOUND 1. A NATURAL SOUND PRODUCED BY NATURE 2. ARTIFICIAL SOUNDS ARE SOUNDS CREATED BY HUMAN ACTIVITY TYPES OF SOURCES POINT SOURCES – simplest source, generated at ideal location in space, omnidirectional point source radiates sound in all directions equally, most real world sources LINE SOURCES – sound resonating line in space, traffic noises from highway, pipes that carry noisy flowing liquid, public address line arrays SURFACE (PLANE) SOURCES – line source extended in 2 dimensions, from whole surface receivers – picks up sound equally from all directions, electroacoustic devices that convert sound waves into electrical signals and numerical sequences, living things with a hearing system humans – binaural receivers, both left and right ear as well as head shape angle of incidence – equal to angle of reflection THE HEARER OF THE SOUND ACTUALLY HEARS 2 TYPES OF SOUNDS DIRECT OR ORIGINAL SOUND – from the source and directly delivered to the hearer REFLECTED SOUND – all directions of the room for a sound to be heard by a listener comfortably directivity – measures a sound source’s directional quality, important in reverberant spaces q sources – like human speech or balloon pops will uniformly excite the reverberant field directional sound – idea of employing various gadgets to create sound fields that spread less than most standard loudspeakers transduction method – no effect on the sound field directionality frequency/pitch – sound quality that distinguishes high from low sounds, number of vibrations per second of soundwave hertz – scientific term for vibrations speed velocity – aka wave velocity, distance traversed by a periodic, cyclic, motion per unit time, speed and direction, product of wavelength and frequency wavelength – distance between consecutive corresponding points of the same phase on the wave frequency – no. of completed wave cycles per second, how many wave crests pass a given point in a sec molecular absorption – sound maybe covered up or absorbed by another sound, this phenomenon is called masking of sound soporific effect – effect brought about by a low steady sound 20hz to 2000hz – human range of hearing ultra low sound – frequency lower than 20hz ultra high sounds – higher than 2000hz loudness – refers to how loud or soft a sound seems to a listener, intensity of soundwaves amplitude – max distance the particles in a medium move from their rest positions as the wave passes through the medium, determines its relative loudness dynamic level – in music, the loudness of a note is called --- intensity – amount of energy that passes through a sqm of space in 1 sec bel – derived from name of Alexander Graham Bell, inventor of telephone decibel – used because a one-decibel difference in loudness between 2 sounds is the smallest difference detectable by human hearing sound intensity – measured with a sound level meter or sound pressure level SPL meter timbre – refers to tone color, feel of sound, different wave shapes, sound quality which makes it possible to identify the object that produces the sound, aka tone quality, sound quality of a musical note, distinguishes different types of sound production such as choir voices and musical instruments timbre – what makes a particular musical instrument or human voice have a different sound from another instruments – will sound distinctively with its own unique tone color experienced musicians – able to distinguish between different instruments of the same types based on their timbres frequency – richness of a sound or note a musical instrument produces fundamental frequency – lowest frequency dominant frequency – frequency that is most heard, always a multiple of the fundamental frequency envelope – timbre of a sound is also greatly affected by the following aspects of its ------: attack time and characteristics, decay, sustain, release (ADSR envelope) and transients THREE CLASSIFICATIONS OF SOUNDS IN A BUILDING NOISE – unwanted sound MUSIC – generally not always made up of ordered sound SPEECH – consists of both ordered and disordered sound SOUND CAN BE DIVIDED INTO 2 CATEGORIES: ORDERED AND DISORDERED harmonics – are overtones that have this simple relationship of frequencies disordered sound – exemplified by street noise, highly irregular in character sound spectrograms – can be used to highlight this irregularity music – made up of ordered sound in most cases speech – how we say sounds and words SPEECH INCLUDES ARTICULATION – how we make speech sounds using the mouth, lips, and tongue VOICE – how we use our vocal folds and breath to make sounds, can be loud or soft, high-low pitch, can be hurt by talking too much, yelling, coughing FLUENCY – rhythm of speech, repeat sounds or pause while talking language – comes from the spoken word air – passes the vocal cords and creates sound phonemes – individual and distinctive sounds that to an extent vary from language to language 500 hz – male voice centers it energy around ---- 900 hz – female voice centers around --- speech – should consist of a flow of various combinations of vowel and consonant sounds music – much broader and complex than speech in frequency and dynamic range reception of music – combination of physiological and psychological phenomena APPROACH OF MUSIC THERAPY PRACTITIONERS RESPONSE APPROACH – focuses on the therapeutic power of music heard form an external source and the body and mind’s reaction to such music EXPRESSION APPROACH – identifies music’s power to come not only form its reception but also from its creation noise – defined as unwanted sound, become increasingly acknowledged as an environmental stressor and as a nuisance annoyance – most prevalent community response in a population exposed to environmental noise noise annoyance – can result from interference with daily activities, feelings, thoughts, sleep, or rest noise annoyance – excessive noise/disturbance that may have a negative effect on health or quality of life THE GOVERNMENT DEFINES 3 LEVELS NO OBSERVED EFFECT LEVEL – the level of noise exposure where there is no effect on health or the quality of life LOWEST OBSERVED EFFECT LEVEL – adverse effects on health and the quality of life can be detected SIGNIFICANT OBSERVED ADVERSE EFFECT LEVEL – there can be significant effects on health and quality of life