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P D Schomer

Publications and source records attributed to P D Schomer.

7 recordsLinked to original sources
PubMed2001

Evaluation of loudness-level weightings for assessing the annoyance of environmental noise.

Assessment of the annoyance of combined noise environments has been the subject of much research and debate. Currently, most countries use some form of the A-weighted equivalent level (ALEQ) to assess the annoyance of most noises. It provides a constant filter that is independent of sound level. Schomer [Acust. Acta Acust. 86(1), 49-61 (2000)] suggested the use of the equal loudness-level contours (ISO 226, 1987) as a dynamic filter that changes with both sound level and frequency. He showed that loudness-level-weighted sound-exposure level (LLSEL) and loudness-level-weighted equivalent level (LL-LEQ) can be used to assess the annoyance of environmental noise. Compared with A-weighting, loudness-level weighting better orders and assesses transportation noise sources, sounds with strong low-frequency content and, with the addition of a 12-dB adjustment, it better orders and assesses highly impulsive sounds vis-a-vis transportation sounds. This paper compares the LLSEL method with two methods based on loudness calculations using ISO 532b (1975). It shows that in terms of correlation with subjective judgments of annoyance-not loudness-the LLSEL formulation performs much better than do the loudness calculations. This result is true across a range of sources that includes aircraft, helicopters, motor vehicles, trains, and impulsive sources. It also is true within several of the sources separately.

Humans↗
PubMed1989

Indoor human response to blast sounds that generate rattles.

The two major noise sources that cause environmental problems for the U. S. Army are helicopters and large weapons such as artillery, tanks, and demolition. These large weapons produce blast sounds that contain little energy above 200 Hz and that are particularly troublesome to deal with because they excite rattles in structures. The purpose of this study was to systematically test subjective response to the presence or absence of rattles in otherwise similar blast sound environments. A second purpose of the study was to test if there were structural changes that could reduce annoyance within the indoor blast sound environment. This study was done using a specially constructed test house and highly repeatable shake table to generate the blast sounds. The data clearly show that no commonly used environmental noise measure adequately describes the indoor environment when the blast excites rattles. Although the indoor blast ASEL changes by only about a decibel or so (and the indoor blast CSEL changes by even less), the subjective response changes by up to 13 dB. At low blast levels, the increase in human annoyance response is largest, and this annoyance response offset decreases to about 6 dB when the outside, flat-weighted peak sound-pressure level of the blast increases from 112 to 122 dB.

Acoustics↗
PubMed1985

Assessment of community response to impulsive noise.

The U.S. Army Construction Engineering Research Laboratory has completed community attitudinal surveys at two major Army installations. The main purpose of these surveys was to better understand community response to the impulsive noise generated by large Army weapons such as tanks, artillery, or demolition. The results show that an energy type of model such as the C-weighted day/night average sound level (CDNL) is the best available descriptor for community response for these types of impulsive sound. Growth in annoyance to all noises increases monotonically with both sound amplitude and frequency of occurrence. This descriptor should incorporate a nighttime adjustment on the order of 10 decibels (dB). The exact function for relating the percentage of a community highly annoyed to CDNL remains in question. It appears that the present National Academy of Science Committee on Hearing, Bioacoustics and Biomechanics (CHABA) recommendation may underestimate actual annoyance, and that the functional relation between annoyance and CDNL should be shifted by 3-4 dB. However, more research on the percentage of a community highly annoyed versus CDNL and the existence and value of community rise- and decay-time constants is required to clarify this issue.

Attitude↗
PubMed1983

A survey of community attitudes towards noise near a general aviation airport.

This paper describes a community attitudinal noise survey performed in the vicinity of the Decatur, Illinois Airport. Two hundred thirty-one respondents were drawn from four distinct noise zones in populated areas near the airport. The day/night average sound levels (DNL) ranged from 44-66 dB. The area is otherwise quiet, residential with large (1/2 acre) lots. The primary analysis arrayed the percent of respondents highly annoyed versus DNL. Good agreement was found between the results of this survey and the general relation developed by Schultz from surveys worldwide, primarily in the vicinity of large commercial airports and highways. In addition, reasonable comparisons were found between respondent estimates of the number of aircraft operations and actual traffic counts. It was also found that respondents who were highly annoyed by aircraft noise were three to four times as likely to be highly annoyed by some other noise than were other respondents.

Aircraft↗
PubMed1978

Human response to house vibrations caused by sonic booms or air blasts.

Descriptions of the effects of sonic booms of air blasts by observers in buildings have included such statements as "noticeable vibrations" in addition to phrases such as "the house rattles," "the windows rattle," or "bric-à-brac rattles." Analysis of studies of human response to vibrations, vibration complaints in the Toronto area, special tests by Kryter at Edwards Air Force Base, and laboratory studies of human response to sonic booms show that perceived vibration is not normally a factor that contributes significantly to human response to airborne, large-amplitude impulse noise. Rather, human response is solely the result of the impulse noise itself and of audible noise due to induced radiation from vibrating surfaces.

Affect↗
PubMed1978

Growth function for human response to large-amplitude impulse noise.

The U. S. Environmental Protection Agency has proposed the use of C-weighted day/night level for the assessment of impulse noise such as the noise resulting from sonic boom, blast noise (artillery, armor, demolition, etc.) and other large-amplitude impulse sources. One remaining question pertaining to the use of C-weighting has been the growth function for human response to impulse noise. This question arises because work by Kryter and by Young using peak values and/or small amplitudes exhibited growth functions of 6--7dB for a doubling of annoyance, while the growth function for human response to common sources (planes, vehicles, etc.) increases by about 10 dB for a doubling of annoyance. Kyter's and Young's data are reanalyzed herein by using C-weighting and by including only large-amplitude data. This reanalysis results in a growth function for human response to impulse noise which increases by about 10 dB for a doubling of annoyance. This equality of growth function between common A-weighted noise and C-weighted impulse noise further supports the use of C-weighted day/night level for assessment of sonic boom, blast noise, or other large-amplitude impulse noises having similar spectral content.

Humans↗