The Effect of Quiet on Hearing (2006)
Nixon, Charles W., Stephenson, Mark R.
The hearing of subjects participating in psychoacoustic experiments may be elevated (temporary hearing loss) due to environmental noises encountered prior to their arrival at the test site. Hearing...
Primary Components of Simulated Air Bag Noise and Their Relative Effects on Human Hearing. (2005)
Sommer,Henry C., Nixon,Charles W.
The relative contributions to auditory temporary threshold shift (TTS) of the air bag vehicle volume displacement and of the high frequency noise burst associated with activation, air turbulence,...
ATTENUATION CHARACTERISTICS OF EARMUFFS AT LOW AUDIO AND INFRASONIC FREQUENCIES. (2005)
Nixon,Charles W., Hille,Harald K., Kettler,L. Keith
Sound attenuation and transmission loss characteristics of three different earmuffs models were determined from (1) physical measurements of discrete frequency signals in the range from 1 to 500 Hz...
SPEECH IN AN ARTIFICIAL ATMOSPHERE (44% OXYGEN-56% HELIUM). (2005)
Nixon,Charles W., Trimboli,Frank, Mabson,William E., Endicott,James E., Welch,B. E.
Intelligibility and physical characteristics of helium speech were investigated during a simulated space mission at Brooks Air Force Base, Texas. Speech was produced under conditions of room air at...
INFLUENCE OF SELECTED VIBRATIONS UPON SPEECH (RANGE OF CPS AND RANDOM). (2005)
Nixon, Charles W., Sommer, Henry C.
Certain characteristics of speech production are altered during low-frequency vibration (2-20 cps) of the talker. In view of this, speech com munication is not at all assured during the vi bration...
EFFECTS OF SONIC BOOM ON PEOPLE: ST. LOUIS, MISSOURI, 1961-1962 (2005)
Nixon, Charles W., Borsky, Paul N.
The vicinity of St. Louis, Missouri, was exposed to approximately 150 sonic booms during a 10-month period from July 1961 to April 1962. Ground overpressures, ranging up to about 3 lb/sq ft, were...
Hearing Protection of Earmuffs Worn over Eyeglasses (2003)
Nixon, Charles W., Knoblach, W. C.
The hearing protection ordinarily provided by earmuffs is reduced when worn by persons who also wear eyeglasses because sound enters the device through air leaks around the eyeglass temple - earmuff...
Human Temporary Threshold Shift and Recovery from 24 Hour Acoustic Exposures, (2002)
Nixon,Charles W., Krantz,David W., Johnson,Daniel L.
The effects on hearing sensitivity of 24 hour monotic exposures to a narrow band noise with the center frequency at 1000 Hz at sound intensities of 80, 85, and 90 dB(A) were evaluated. Automatic...
Moore,Thomas J,, McKinley,Richard L., Mortimer,Vincent D., Nixon,Charles W.
The communication effectiveness of words processed through two modems of a spead spectrum radio system during various jamming conditions was measured in the presence of the simulated noise of an...
Nixon,Charles W., Decker,William H.
The voice communications effectiveness of the all-purpose MCU-2/P chemical defense protective mask for use by all ground personnel was evaluated in a laboratory study. Speech intelligibility was...
B-52G Crew Noise Exposure Study. (2002)
Decker,William H., Nixon,Charles W.
The B-52G aircraft produces acoustic environments that are potentially hazardous, interfere with voice communications and may degrade task performance. Numerous reports from aircrew of high noise...
Nixon,Charles W., Sommer,Henry C.
Detailed technical information and instructions are provided for a simple modification of the Air Force standard H-133 ground communications headset for use in intense noise environments at levels of...
Human Real Time Perception in Noise. (2002)
Stock,Michael J., Nixon,Charles W., Fisher,Vernie G. , III, Goodyear,Charles D.
A novel device, the Real Time Perception Analyzer (RTPA), has been developed to measure the perception of real time as well as simple and choice reaction time under microgravic conditions on board...
RAIL TEST TO EVALUATE EQUILIBRIUM IN LOW-LEVEL WIDEBAND NOISE, (1998)
Nixon,Charles W., Harris,Charles S., VON Gierke,Henning E.
Psychomotor performance on a rail test was measured during free-field exposure to wideband noise at an overall level of 120 dB re 0.0002 dyne per square centimeter. Subjects wore various combinations...
SPEECH IN AN ARTIFICIAL ATMOSPHERE (30% HELIUM-70% OXYGEN). (1998)
Nixon,Charles W., Mabson,William E., Trimboli,Frank, Welch,B. E.
During a simulated space mission, speech was analyzed to investigate the effects on communication of a 56-day exposure to a cabin atmosphere composed of 30% helium and 70% oxygen at an altitude of...
Nixon,Charles W., Hill,Michael E.
An investigation was made of relative voice communication efficiency of oxygen masks equipped with different respiration valves. A practical test protocol was established for quantifying oxygen mask...
LCP-10 Intelligibility of Oxygen Masks and Microphones in Aircraft Noise. (1998)
Nixon, Charles W., McKinley, Richard L.
A series of studies was conducted to examine the effectiveness and limitations of the Joint Tactical Information Distribution System (JTIDS) voice channel in noisy environments. Initial efforts to...
Nixon, Charles W., McKinley, Richard L.
Voice communications processed by Linear Predictive Coders (LPC) are vulnerable to degradation by noise. An earlier study demonstrated that the major effect occurs at the listener. Possible...
Nixon, Charles W., Stephenson, Mark S., McKinley, Richard L., Fisher, Vernie G., Jacobs, Michael J.
The intelligibility in noise of normal and digital speech (ADPCM, CVSD, LPC-10 vocoders) was measured for normal hearing and hearing impaired listeners. The digitally coded speech was generally less...
Nixon, Charles W., Decker, William H.
The voice communications effectiveness of the all-purpose MCU-2/P chemical defense protective mask for use by all ground personnel was evaluated in a laboratory study. Speech intelligibility was...
The goal of national and international measurement standards is to provide consensus procedures that produce reliable qualitative and quantitative data. A standard measurement procedure is expected...
A Glimpse of History: The Origin of Hearing Conservation Was in the Military? (1998)
In the beginning--actually, we skip the beginning and start around the time of World War II. There were no hearing conservation programs in the military! Aural rehabilitation remained the main focus...
Vulnerability of Female Produced Speech in Operational Environments. (1997)
Nixon, Charles W., Morris, Linda J., McCavitt, Angela R., McDaniel, Mark P., Anderson, Timothy R.
The role of women in combat environments has expanded dramatically. The accommodation of females in these previously male dominated environments is vital to fully successful mission accomplishment....
Symposium on Speech Communication Metrics and Human Performance. (1997)
Various metrics are used to evaluate different aspects of speech communication. Most popular are measures of speech intelligibility. Other metrics that measure more than intelligibility are being...
Vulnerability of Female Produced Speech in Operational Environments. (1996)
Nixon, Charles W., Morris, Linda J., McCavitt, Angela R., McDaniel, Mark P., Anderson, Timothy R.
The role of women in combat environments has expanded dramatically. The accommodation of females in these previously male dominated environments is vital to fully successful mission accomplishment....