acous-, acou-, acouo-, acoustico-, acouto-, acousti-, -acousia, -acousis, -acoustical, acu-, -acusis-, -acusia

(Greek: akoustikos, to hear, hearing; to listen, listening)

anacoustic zone; zone of silence (s) (noun); anacoustic zones; zones of silence (pl)
An area in outer space where sound cannot be transmitted: The anacoustic zone is said to be the upper portion of the earth's atmosphere starting at a hundred miles (160 kilometers) and on into interplanetary space, where sound cannot be projected because gas molecules are too far apart to serve as a transferring medium.

The anacoustic zone is also known as the "zone of silence".

anacusia, anakusia, anakusia (s) (noun); anacusias, anakusias, anakusias (pl)
The total loss or absence of the ability to perceive sounds; deafness: Due to a genetically inherited defect, Horatio developed anacusia before he was 40 years old.
atmospheric acoustics (s) (noun) (a plural form used as a singular)
The propagation of sound through the layer of gases surrounding the earth's surface, which affects sound in predictable ways depending on conditions; such as, temperature and precipitation: "When setting up for the outdoor concert, the sound engineers had to take atmospheric acoustics into consideration including factors such as moisture in the air, placement of speakers on the ground, etc."
bioacoustics (s) (noun) (a plural form that is used as a singular)
1. The science dealing with the effects of sound fields or mechanical vibrations in living organisms: "As an experiment for her botany class in high school, Kelly designed a project to test the bioacoustics of loud music on the growth of sweet peas."
2. The science of communicating sounds that are made by animals: "Dolphins are frequently the subject of studies of bioacoustics as zoologists study the communication techniques among them."
bradyacusia (s) (noun), bradyacusias (pl)
An abnormal dullness or lack of hearing: "The doctor concluded that the bradyacusia which the patient was suffering was caused by a damaged nerve."
catacoustics (s) (noun) (a plural that functions as a singular)
The science of reflected sounds: "The acoustical engineer which the university hired understood the catacoustics that were needed in the auditorium and made the appropriate structural recommendations to cut down on the sounds that were bouncing off the walls."
diacoustic (s) (noun), diacoustics (pl)
The science of spreading or bouncing sounds around: "Carson was an expert in diacoustics and was researching the qualities of surfaces that refracted or diverted sounds in different directions."
diplacusis (s) (noun), diplacuses (pl)
1. The hearing of the same sound differently by one ear than by the other one so that a single sound is perceived as two: As a musician, Jasper realized that the displacusis from which he suffered was getting progressively worse and he realized that he would need to change careers if his condition could not be cured.

Iris thought she was losing her mind when she first developed diplasusis, because she was concerned that she was hearing duplicate sounds when she was sure she only should have heard just one.

2. Etymology: from Greek dipl-, "two fold, double" + akousis, "hearing".
dysacousia, dysacusia (s) (noun), dysacousias, dysacusias (pl)
1. Discomfort caused by loud noises: "Because he suffered from dysacousia, Henry always sat in a quiet spot in the library so the noise made by others would not bother him."
2. A disorder characterized by a distortion in the quality of the sounds being heard; such as, musical notes: "Despite her interest in music, Nancy decided that she would not become a musician because of the dysacousia which made it too difficult for her to distinguish the musical tones."

We have two ears and only one tongue in order that we may hear more and speak less.

—Diogenes

If you don’t want your children to hear what you’re saying, pretend you’re talking to them.

—Anonymous

If there are any of you at the back who do not hear me, please don’t raise your hands because I am nearsighted.

—W.H. Auden (1907-73) British poet

[Isn't that similar to saying, "If those of you in the back can’t hear me, raise your hands"?]

echoacousia (s) (noun), echoacousias (pl)
A hearing defect in which sounds bounce and are repeated instead of being perceived as normally heard sounds: "Manfred found that the echoacousia which he was experiencing was very distracting; especially, when he is trying to listen to music, his TV, or what people are saying to him."
echoacusis (s) (noun), echoacuses (pl)
An auditory condition in which there is an echo effect when someone is hearing sounds: "While listening to his favorite band on a CD, Jake was very upset by the echoacuses which were reverberating or being abnormally repeated in his ears."
electroacoustic (adjective) (usually not comparative)
A reference to the operation or function of a loudspeaker or microphone, etc.: "An electroacoustic process involves both electricity and acoustics (sounds) or the relationship of acoustic energy and electric energy."
electroacoustic locator (s) (noun), electroacoustic locators (pl)
A device for locating foreign objects in the human body: "In surgery, an electroacoustic locator amplifies the sound made when an object is touched by a probe."
electro-acoustic music, electroacoustic music (s) (noun); (usually not in the plural form)
The electronic generation and processing of audio signals or the electronic processing of natural sounds, and the manipulation and arrangement of these signals via tape recorders into a finished musical composition: "Electro-acoustic music is recorded and edited on tape and the reproduction involves the use of loudspeakers."

"Some electroacoustic music is created by arranging electronically synthesized sounds into a formal pattern with musical qualities which might resemble those of normal musical instruments."

electroacoustic transducer (s) (noun); electroacoustic transducers (pl)
A device that produces energy waves from electricity to sound or from sound to electricity: Examples of electroacoustic transducers include such devices as microphones, earphones, and loudspeakers.

If you would like to take a self-scoring quiz over many of the words in this unit, then click on this Hearing Quiz link so you can see how much you know about some of these “acous-, acou-” words.

Related "hear, hearing; listen, listening" units: audio-; ausculto-.