TECHNICAL REPORT STANDARD TITLE PAGE 

1. Report No. ~. Government Accession No. 3. Recipient's Catalog No. 

FAA-AM-72-35 

4. Title and Subtitle 5. Report Date 

December 1972 

SIMULATED SONIC BOOMS AND SLEEP: EFFECTS OF 6. Performing Organization Code REPEATED BOOMS OF 1.0 PSF 

7. Author( s) 8. Performing Organization Report No. 

William E. Collins, Ph.D. 

P. F. Iampietro, Ph.D. 

9. Performing Organization Name and·Address 10. Work Unit No. 

FAA Civil Aeromedical Institute 

P. 0. Box 25082 11. Contract or Grant No. 

Oklahoma City, Oklahoma 73125 

13. Type of Report and Period Covered 

12. Sponsoring Agency Name and Addres• 

Office of Aviation Medicine OAM Report 

Federal Aviation Administration 

800 Independence Avenue, s.w. 14. Sponsari ng Agency Code 

Washington, D. c. 20591 

15. Supplementary Notes 

This research was performed under Tasks AM-B-70-PSY-24, AM-B-71-PSY-24, and 

AM-B-72-PSY-24. 

16. Abstract 

Eight male subjects in each of three age groups (21-26, 40-45, 60-72 years) slept 

in pairs in the CAMI sonic boom simulation facility for 21 consecutive nights. 

The first five nights were used to acclimate the subjects (nights 1 and 2) and to 

obtain Baseline data (nights 3-5); the 12 subsequent nights (Boom) involved the 

hourly presentation of simulated sonic booms at an overpressure level of 1.0 psf 

(as though measured "outdoors"); during four additional nights (Recovery) there 

were no boom presentations. All-night records of EEG, EOG, EMG, ECG, and BSR were 

obtained and analyzed. None of these physiological measures showed any statistically significant effect of the boom presentations on nightly sleep patterns. 

However, the individual booms did arouse ECG, E~, and BSR responses in all subjects; average heart rate increased during the minute following each boom (by less 

than one beat per minute), EMG responses occurred for 45-50 per cent of the booms, 

and BSR changed following 19 per cent of boom presentations. The frequency of 

these occurrences increased as a function of age. That these changes were probabl' 

mild is supported by the facts that only 5 per cent of the booms produced awakening and only 14 per cent produced shifts in stages of sleep (4 per cent of the 

stage shifts might be expected by chance); both of these measures showed higher 

frequencies of occurrence as a function of age. The changes in sleep appear 

roughly comparable to what might occur in response to the noise of a passing 

truck at 40-45 dBA. 

17. Key Words 18. Distribution Statement 

Sonic Boom Availability is unlimited. Document may 

Sleep be released to the Nat:io nal Technical 

Noise Effects Information Service, Springfield, Virginia 

22151, for sale to the public. 

19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price 

Unclassified Unclassified 27 $3.00 

Form DOT F 1100;7 la-s91 
ACKNOWLEDGMENT 

We gratefully acknowledge the assistance of William Schicht who supervised both the nightly collection of physiological data by graduate students 

from the University of Oklahoma Health Sciences Center and the scheduling 

of those assistants; of Wesley Beaver who was an on-site supervisor and 

physiological data collector; of the CAMI Technical Staff (AAC-106) for 

maintenance of the simulator and the physiological tape recorder; of Drs. 

W. Dean Chiles and Roger C. Smith who, respectively, directed the performance measurement and the mood assessment aspects of the study; of Blair 

Fennell, Cynthia Mitchell, Karen Lewis, Georgetta West, Gary Hutto, and 

RuthAnn Parvin who collected and scored the mood and the performance 

data; of Dr. Jerry V. Tobias who evaluated the audiograms obtained from 

the subjects by Walter E. Morris; and particularly of Drs. Thomas Roth and 

Milton Kramer who scored and statistically analyzed the physiological data 

under FAA Contract DOT-FA 70AC-1125-3. Funds for the contract were 

provided by the FAA Office of Noise Abatement under the advisement of 

Mr. Ray Shepanek. 
SIMULATED SONIC BOOMS AND SLEEP: EFFECTS OF 

REPEATED BOOMS OF 1.0 PSF 

I. Introduction. 

In the N AS-NRC Report on Human Responses to the Sonic Boom ( 1968), it was noted 

that "Understanding human response to the 

sonic boom is sufficiently important to warrant 

high priority for the maximum use of simulation 

facilities. . . . It is important to know more 

about the response of an individual to the sonic 

boom as a function of his ongoing activities such 

as skilled motor performance ... sleep at night .... 

These relations should be studied independently 

for infants, children, and adults of all ages .... " 

Among the questions cited as particularly relevant as a background for management decisions 

were: "Do repeated booms cause changes in the 

depth of sleep as judged by the electroenceph· 

alogram (EEG) ? Does the stimulated subject 

develop a chronic deficit of important stage of 

sleep? . . . . Do repeated brief awakenings of 

normal subjects cause behavioral changes, psychological distress or excessive fatigue?" 

Relatively little research has been conducted 

concerning the effects of sonic booms on sleep 

behavior. However, there is a good deal known 

about the general influence of noise on sleep 

patterns (e.g., Dobbs, 1970; Kryter, 1970; Williams, 1970). A number of laboratory studies 

(Goodenough, Lewis, Shapiro, Jaret, and Sleser, 

1965; Kramer, Roth, Trindar, and Cohen, 1971; 

Oswald, Taylor, and Triesman, 1960; Rechtschaffen, Hauri, and Zeitlin, 1966; Williams, 

Gieseking, and Lubin, 1966; \Villiams, Hammack, 

Daly, Dement, and Lubin, 1964; \Villiams, Morlock, and Morlock, 1966 ; Williams and Williams, 

1966; Zung and Wilson, 1961) using different 

auditory stimuli have shown that waking responses are a function of the following variables: 

individual differences, intensity of the acoustic 

stimulus, age of the sleeper, sex of the sleeper, 

time of night, stage of sleep, amount of accumulated sleep, and personal significance of the 

auditory stimulus (e.g., the sleeper's own name). 

1 

Moreover, most physiological responses (e.g., 

brain wave activity, heart rate) appear to show 

little or no adaptation to acoustic stimulation 

during sleep. 

Of the very small number of studies involving 

sonic booms and sleep behavior, most have been 

conducted by Lukas and his co-workers (Lukas, 

1970; Lukas and Dobbs, 1972; Lukas, Dobbs, and 

Kryter, 1971; Lukas and Kryter, 1968, 1970a, 

1970b). Those several studies involved a total 

of 22 male and female subjects who were exposed 

to simulated sonic booms (ranging in "outdoor" 

intensities from 0.6 to 5.0 psf) and to recordings 

of subsonic jet flyover noise (ranging in "outdoor" intensity from 101-119 PNdB). With the 

exception of four middle.aged females, subjects 

were tested frequently but on non-consecutive 

nights; the female exceptions were tested for 14 

consecutive nights (Lukas and Dobbs, 1972). 

Results of these studies, using criteria of arousal 

and awakening, may be summarized as follows: 

(1) children (5-8 years of age) appear to be 

undisturbed by noise during sleep; (2) in general, younger subjects are less sensitive to noise 

than are older subjects; (3) irrespective of age, 

individuals may show considerable variability in 

relative sensitivity to noise during sleep; ( 4) 

men appear to be less sensitive to noise than do 

women ; and ( 5) the occurrence of behavioral 

awakening is a function of the intensity of the 

noise (Lukas, 1970). Morgan and Rice (1970) 

indicate that awakening appears to be related 

more closely to accumulated sleep time than to 

stage of sleep. 

The present study was designed to investigate 

the effects on sleep of simulated sonic booms 

occurring regularly during the night over a consecutive 12-night period. Possible effects of the 

booms on subjective states and on objective measures of performance were also examined. An 

overpressure level of 1.0 psf (as measured "outdoors") was selected as the boom stimulus. The 
selection of this stimulus as an "acceptable" one 

was a compromise based partly on determinations 

from other studies which indicated that sonic 

boom overpressure levels of 0-1.0 would produce 

no significant public reaction day or night, while 

levels of 1.0-1.5 would produce probable public 

reaction (von Gierke, 1966). The 1.0 psf level 

has been likened to the sound of moderate thunder (Richards and Rylander, 1972) or of moderate to distant thunder (Ferri and Schwartz, 

1972). 

II. Method. 

Facility 

This study was conducted in the sonic boom 

simulator facility at the Civil Aeromedical Institute (CAMI). The facility was designed and 

constructed by the Stanford Research Institute 

(SRI) and was modeled after their device according to CAMI requirements. A detailed description of the SRI facility can be found in a 

paper by Lukas and Kryter (1968) and a description of the CAMI facility appears in a 

report by Thackray, Touchstone, and ~Tones 

( 1971). Briefly, the facility at CAMI consists 

of two components, the boom generator and the 

test room, both of which are slightly larger than 

those at SRI. The boom generator (Figure 1) 

is an electromechanical device which -can be set 

to provide simulated booms of various intensities 

directly to the test chamber (Figure 2). A 

piston, which is connected to a tightly sealed 

pressure chamber (Figure 1) causes a pressure 

change in the chamber when a "one-shot" clutch 

is activated. A cam, which rotates through 360°, 

can be offset to vary the intensity of the boom; 

the spring load can be varied to change the rise 

time of the boom while the motor speed determines the duration of the boom. In this study, 

the boom intensity was set at 1.0 psf, the rise 

time was 6.8 msec, and the boom duration was 

299.5 msec. Inside the test room, the comparable 

data were 0.13 psf, 12.1 msec, and 283.6 msec, 

respectively ( cf., Thackray et al., 1971). Sound 

levels of the booms, as measured by a B&K Impulse Precision Sound Level Meter (Type 2204), 

were approximately SO dBA on the Impulse setting and 68 dBA on the Slow setting, at the 

position of a given subject's head. 

The test room was constructed to simulate a 

middle bedroom in a frame house. The walls of 

the test room are of standard dry wall construe2 

tion. One wall of the pressure chamber (Figure 

1) forms the "outside" wall of the test room. 

There are two windows in the room-one in the 

"outside" wall and one (of one-way glass) in the 

opposite wall which was used for observation of 

the subjects by the experimenters. 

Physiological 11/ easurements 

All physiological measurements were recorded 

on Beckman Type RM 8-channel polygraphs. 

Recordings were made of the electroencephalogram (EEG), electro-oculogram (EOG), electromyogram (EMG), electrocardiogram (ECG), 

and the basal skin resistance (BSR). EOG, 

EMG, and EEG are measures which are used 

primarily to score stages of sleep, while ECG 

and BSR are primarily indicators of the level 

of arousal of an individual. One polygraph 

channel served as an event marker for the presentation of sonic booms. In addition, all data 

were simultaneously stored on magnetic tape by 

means of a 16-channel Ampex tape recorder, 

Model SP 300. Tape speed was 1% ips; polygraph paper speed was 1 em/sec. 

Electrode placement sites and recording techniques employed for EEG, EOG, and EMG were 

those suggested by Rechtschaffen and Kales 

( 1968). Acetone was used to clean all electrode 

sites and Redux paste was used for EEG and 

EMG sites prior to electrode application. EEG 

electrode sites were rotated between C4/ A1 and 

C3/ A2 (Ten-Twenty system) on alternate nights 

in order to minimize skin irritation. A standard 

Grass silver disc EEG electrode filled with 

Grass EC-2 electrode cream was attached to the 

scalp site (either C3 or C4) with a collodionsoaked one-inch-square gauze pad, and the reference electrode (either A1 or A2), similarly filled 

with EC-2 cream, was taped to the earlobe by 

means of Blenderm surgical tape. Polygraph 

settings for EEG were 50 microvolts/centimeter 

gain, and 0.3-second time constant. 

For EOG, one standard EEG electrode, filled 

with electrode cream, was taped near the outer 

canthus of each eye, and both electrodes were 

referred to the previously described electrode 

located either at A1 or A2. This arrangement 

was used in order to identify the horizontal 

conjugate eye movements associated with the 

rapid eye movement (REM) stage of sleep. 

Recorder settings for these two EOG channels 
FIGURE 1. The boom generator section of the CAMI sonic boom simulation facility. The pressure chamber at the 

right is immediately adjacent to the test room (see Figure 2). 

were 100 microvolts/centimeter gain, and 0.3-

second time constant. 

The two electrodes used for detecting EMG 

were standard EEG electrodes filled with electrode cream and taped to the underside of the 

jaw. One electrode was placed approximately 

one inch behind the point of the chin over the 

insertion of the submental muscle; the second 

electrode was attached about one and one-half 

inches behind the first electrode at a point just 

short of the terminus of the jaw bone. On alternate nights, homologous sites on the opposite 

side of the jaw were used in recording EMG. 

Recorder settings for EMG measurement were 

the following: gain was varied between 10--40 

3 

microvolts/centimeter (depending on signal 

strength) with the most common setting being 

20 microvolts/centimeter, a 0.1-second time constant was maintained without high-frequency 

filtering. One polygraph channel recorded an 

integration of the EMG responses. The direct 

EMG signal was passed through a Beckman 

Type 9852A EMG averager (time constant: 0.2 

seconds) and the amplified output of this coupler 

was written out on the polygraph. This averaged 

EMG signal was not placed on tape. 

ECG was derived from two standard EEG 

electrodes taped to the subject's thorax. One 

electrode was taped just below the trapezius 

muscle on the right side of the back, and the 
FI!iURE 2. The test room of the CAMI sonic boom simulation facility. The window and wall at the head of the 

beds are adjacent to the pressure chamber. 

second electrode was located approximately near 

the bottom of the left-side rib cage. EEG, EOG, 

ECG, and direct EMG signals were all carried 

to the amplifiers via standard Beckman A-C 

couplers Type 9806A. 

BSR tracings were obtained from two Beckman biopotential ( silver-silver chloride) electrodes, filled with K-Y surgical jelly, and taped 

to the palmar surface of the distal segment of 

the right forefinger and right ring finger. The 

Beckman Type 9892A skin resistance coupler was 

employed in this recording circuit. This coupler 

is a constant current device whose output signal, 

after appropriate amplification, can be scored 

directly in terms of resistance unit. Amplifica4 

tion of the BSR signal ranged from 2-200 millivolts/centimeter as a function of within- and 

between-subject variation in basal skin resistance. 

Lastly, a two x three inch silver electrode covered 

with K-Y surgical jelly and fastened to the subject's right forearm with an Ace bandage was 

used as the grounding source. 

Mood Assessment 

The Composite Mood Adjective Check List 

(CM:ACL) developed by Malmstrom (1968) was 

used to assess affective states prior to and subsequent to each sleep period. The list consists of 

80 adjectives which the subject rates on a ninepoint scale, with the lower end of the scale indicating a judgment of "not at all" descriptive, and 
the upper end of the scale indicating a judgment 

of "definitely" descriptive, of the subject's current feelings. Each CMACL was scored for the 

15 mood factors listed by Malmstrom as well as 

for an index indicating the overall degree of 

positive or negative affect expressed by the subject. More detailed procedures concerning this 

aspect of the overall study appear elsewhere 

(Smith and Hutto, 1972). 

Performance 111 easltrement 

The CAMI Multiple Task Performance Battery (MTPB) (Chiles, Alluisi, and Adams, 

1968) was used to measure performance of complex tasks before and after each sleep period. 

Briefly, the apparatus was programmed to present two active and two passive tasks to the 

subjects. The former comprised mental arithmetic and pattern discrimination; the latter, 

monitoring lights and monitoring meters. Ten 

performance scores were derived for each subject. 

(1) Red Lights I. Response time to onset 

of red warning lights while performing 

the arithmetic task. 

(2) Red Lights II. Response time to onset 

of red warning lights while performing 

the pattern discrimination task. 

(3) Green Lights I. Response time to the 

offset of green warning lights during 

arithmetic tasks. 

( 4) Green Lights II. Response time to the 

offset of green warning lights during 

pattern discrimination. 

( 5) Meter Monitoring I. Response time to 

detect correctly shifts in the mean positions of fluctuating pointers while 

perfGrming the arithmetic task. 

(6) Meter Monitoring II. Response time 

to detect correctly shifts in the mean 

positions of fluctuating pointers during 

the pattern discrimination task. 

(7) Arithmetic I. Response time to add 

two two-digit numbers, subtract an 

additional two.digit number, and record the answer by means of a set of 

push-buttons. (Note: For the oldest 

group, one-digit rather than two-digit 

numbers were used due to the difficulties experienced in the training session 

by one of the first two 60-72 year olds.) 

(8) Arithmetic II. Percentage of arithmetic problems solved correctly. 

5 

(9) Pattern Discrimination. Patterns of 

six vertical bars each were displayed 

on a screen for two to five seconds. 

Each problem involved a standard and 

two comparison patterns successively 

presented. Subjects pressed one of a 

set of three buttons to indicate whether 

the first, the second, or neither comparison pattern matched the standard. 

Scores comprised the percentage of correct responses. (Note : The task was 

made more difficult for the two youngest age groups by means of programmed random distortions of the 

comparison patterns.) 

(10) Composite for Lights and Meters. The 

sum of the linear transformation of 

scores for Red Lights I and II, Green 

Lights I and II, and Meter Monitoring 

I and II. 

More detailed procedures concerning this aspect of the overall study are reported elsewhere 

(Chiles and West, 1972). 

Subjects 

A total of 24 male subjects was used; eight 

subjects each were in groups aged 21-26, 40-45, 

and 60-72. Data concerning age, education, and 

employment status of these men appear in Table 

1. A week or so prior to the start of a 21-night 

experimental sequence, subject-candidates were 

interviewed, given a hearing test (Bekesy audiometer) , and then administered the Cornell Medical Index Health Questionnaire (to screen out 

subjects who might have severe emotional disturbances). Results from the Cornell Questionnaire and mean audiograms are presented in 

Table 2 and Figure 3, respectively. In selecting 

the 24 subjects used in the study, 12 other candidates were rejected and two others (21-26 year 

olds) served as trial-run subjects for 21 nights 

to test out equipment and procedures. Ten of 

the rejections (two in the youngest, one in the 

middle, and seven in the oldest age groups) were 

based on judgments that their audiograms were 

below approximately normal levels for their age 

groups. The other two rejections were foreign 

students (21-26 year olds) who were judged, on 

the basis of the interview, to have insufficient 

command of the language to be able to follow 

all instructions adequately. Subjects were not 

selected on the basis of physical characteristics, 
Table 1 

Age, Education, aDd Emplo,a.nt Cbaracteriatica of the Three Groups of Subjects 

Employment Status: 

Number in Categories 

Mean Age Median 

Age Gr2!!2• !i {Iearal Education !ltudent lull-Time !lob Retired 

21-26 Year Olda 8 23.3 2.0 Yr. College 5 3 0 

40-45 Year Olds 8 42.1 3.0 Yr. College 1 7 0 

60-72 Year Olda 8 65.1 2.5 Yr. College 0 1 7 

Total& 24 6 -u 7 

Table 2 

Cl .. alficatlon of Subject• Accordlag to Reaponaea Made to the 

CorDell Mecllcal IDclez llaaltb QueatloDD&lre 

CMI Catesorlea: Severity of Emotional Dlaturbauce 

Rot 

Age Groupe ! Sianlficant !!!!4. Moderate ~ 

21-26 Year Olda 8 8 0 0 0 

40-45 Year Olda 8 6 1 1 0 

60-72 Year Olda 8 7 1 0 0 

Tot ala 24 21 T 1 0 

Table 3 

Mean Time to Bed, Time to Rise, Nightly Hours in Bed, and Nightly Awakenings Reported by Subjects 

in Each Age Group Prior to the Experiment. Records of These Sleep Data Were Kept by the 

Subjects for Periods Ranging From 4-10 Days Prior to the Beginning of the Experiment. 

Mean Time 

Age Gro!!:QS !i to Bed (P 1M1 } 

21-26 Year 01ds 8 11:58 

40-45 Year Olds 8 10:32 

60-72 Year Olds 8 10:49 

prior exposure to sonic booms, susceptibility to 

noise, or criteria other than those noted above. 

Subjects who passed the screening tests were 

asked to begin to maintain a daily record of their 

sleep behavior and to present the information 

when they reported for the first of the 21-night 

sessions. The record was to indicate time to bed, 

6 

Mean TiJI!e Mean Hours Mean Nightly 

to Rise ~A l in Bed Awakeni!!,Ss 

7:57 8.0 0.9 

7~08 8.6 0.8 

7:00 8.2 1.6 

time to rise, and number of awakenings for each 

night; these data appear in Table 3. In addition, they were given a brief orientation regarding the conduct of the study and what would be 

required of them. Subjects were not told that 

simulated sonic booms would be presented. They 

were told that CAMI was interested in sleep 
behavior, moods, and performance; that noises 

might occur during the night (including the 

presence of experimenters in the test room to 

adjust or replace electrodes as needed) but that 

their task was to ignore disturbances of any kind 

and get the best night's sleep possible. The 

subjects were then scheduled for a one-hour 

training session on the performance battery, 

usually the day before the 21-day session was to 

begin. 

Prooedure 

Two subjects (from the same age group) reported to the sleep laboratory at 2000 hours each 

night for a total of 21 consecutive nights (Table 

4). The first five nights of sleep in the labora-

~ -lOt _, - .... ~20-YR. OLDS I _J 0 - -... ....... _,.- .... _ _,,.. , _________ _ 

:; +10 

~ ~~t~5~--~2;~o----~5t6o~~75~o~ld-oo~l5~b-o-2o+o-o_3_oo~o-4~o-oo--6~oo~o 

.q 

~ -10 

(/) 

..J 

0 

l.iJ +10 m 

iJ 20 l.iJ 

0 30 

40-YR. OLDS 

~ L__l~25 ____ 2-+5-o _____ 5o~o--751-o--+-loo6-15bo idoo 3obo 4ooo 6ooo ..J 

l.iJ -10 ,....---~--------------------------------, 

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~ 0 

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§! 20~ (/) 

60-YR. OLDS 

i 

<r ~~lc__~l 125 ------+l----~r-~1~-+1~~~~1-l~~~~-+1~~~~ 250 5do 750 1ooo 15oo 2ooo 3ooo 40oo 6ooo 

RIGHT EAR--

LEFT EAR ---

l.iJ 

I FREQUENCY IN HERTZ 

FIGURE 3. Average audiograms for the three age groups. 

tory served two purposes; the subjects became 

adapted to sleeping in the laboratory environment (nights 1 and 2), and Baseline data were 

collected on nights 3-5. During the next 12 

nights, the subjects were presented with a simulated boom ( 1.0 psf "outside" intensity) at hourly 

intervals starting at 2300 hours and ending at 

0600 hours. When the observers determined that 

a subject was not asleep at the time a boom was 

scheduled, the boom was delayed for periods not 

exceeding 10 minutes to allow the subject to fall 

asleep. The final four nights were termed "recovery nights" (no booms presented). 

As indicated in the procedural outline presented in Table 5, at 2000 hours and again at 

7 

Table 4 

General Protocol 

Pre-Experimental Period Hearing test, Cornell Medical Index, 

orientation, training on Multiple Task 

Performance device. 

Experimental Period 

1 ... 2 Adapt ion to laboratory enviroDMnt. 

3 - 5 (Baseline) 

6 - 17 (Boom) 

18 - 21 (Recovery) 

Collec:tion of phya to logical, P.erformance, and mood data; no abulated bo01118 

presented. (Data obtained during these 

two days are not presented in thia 

report.) 

Collection of baseline physiological, 

performance, and mood data; no aimu ... 

la ted boo• presented. 

Collection of phyaiological, performance, and mood data; bOOKM presented 

at hourly intervale from 2300 'to 0600 

hours. 

Collection of physiological, performance, aDd mood data; no af.mulated booms 

presented. 

0700 hours the subjects were tested on the Multiple Task Performance Battery; the test period 

was approximately 30 minutes long. At 2040 

and at 0730 hours, the subjects were administered 

the Composite Mood Adjective Check List. Between 2100 and 2200 hours all electrodes were 

attached and other preparations completed so 

that the subjects would be in bed at 2200 hours. 

Recorders (all located outside the test room) 

were activated and calibrated and continuous 

recordings were made for 500 minutes (8 hours 

and 20 minutes) until the subjects were awakened 

at 0620 hours. 

During the hours the subjects were not in the 

laboratory, they concerned themselves with their 

normal daytime activities. They were requested 

not to nap during the day and, although there 

Table 5 

Daily Protocol 

~ 

2000 hours Ieport to laboratory 

2000-2030 Multiple Task Performance Battery (MrPB) 

2030-2040 Rest Interval 

2040-2050 Composite Mood Adjective Check List (CMACL) 

2050-2100 Rest Interval 

2!00-2145 Attachment of electrodes 

2145-2200 Pre par at ion for bed 

2200-0620 Sleep, recording of physiological data 

0620-0700 Awaken, remove electrodes, dress 

0700-0730 MrPB 

0730-0740 CMACL 

0745 Depart laboratory 
was no attempt to regulate eating or drinking 

habits, the subjects were asked to refrain :from 

excessive use o:f alcohol and to take no alcohol 

at all after 1800 hours. 

Scoring of Physiological Data 

Sleep Profiles 

All-Night Measures. Two channels o:f EOG, 

one o:f EMG, and one o:f EEG were used to score 

stages o:f sleep. Using "A Manual o:f Standardized Terminology, Techniques and Scoring 

System :for Sleep Stages o:f Human Subjects" 

(Rechtschaffen and Kales, 1968), each 30-second 

epoch was scored as: Awake, Movement Time, 

Stage 1 (non-REM), Stage 2, Stage 3-4 or Stage 

REM. The amount o:f time a wake was :further 

divided into the :following categories: ( 1) the 

amount o:f time a wake be :fore sleep onset (A wake 

stage only), (2) the amount o:f time spontaneously awake, (3) the amount o:f time awake 

subsequent to boom presentations, and ( 4) the 

amount o:f time awake between sleep termination 

and arising. To assess the reliability o:f scoring, 

every fifth record was scored by a second person. 

The mean reliability between scorers (epoch by 

epoch) was 90.9 per cent. In addition, every 

tenth record was also scored by the director o:f 

the scoring project. The mean reliability between the two scorers and the project director 

was 94.1 per cent. 

To :further evaluate the nature o:f the sleep 

during the three experimental conditions, latencies to Stage 2 (sleep onset; includes Awake 

stage and Stage 1) and Stage REM were computed. Finally, the number o:f transitions between sleep stages was determined. Three 

different time bases were used to determine the 

number o:f sleep stage transitions ( 30 seconds, 

five minutes, and ten minutes) ; transitions were 

tallied on the basis o:f the predominant stage 

within the selected time period. 

Measures of Responses to the Booms. Sleep 

profile changes in response to the booms were 

scored using the criteria developed by w·illiams 

(see Table 6) and described by Lukas and Kryter 

( 1968). Since there is an inherent variability 

in the sleep record throughout the night, it was 

necessary to compare any changes in sleep resulting :from a boom presentation to a pseudo 

stimulus control condition in which the boom 

was not presented in reality. Therefore, the 

sleep recording 30 minutes prior to an actual 

boom presentation was scored using the \Villiams 

8 

Criteria. The reliability measure :for the Williams Criteria was 90.0 per cent between two 

scorers based on five randomly selected nights 

:for each o:f :four subjects. 

Heart Rate (EOG) 

All-Night Measures. The unit o:f measurement 

:for the ECG data was beats per minute. A oneminute segment out o:f every hour o:f recording 

(on the half-hour) was selected :for scoring. In 

each one-minute sampling every inter-beat interval was measured. To a void artifact, any 

inter-beat interval -+-3 standard deviations :from 

the mean o:f that sample was rejected. Finally, 

any sample which contained less than 20 usable 

inter-beat intervals was rejected. Heart rate :for 

the night was determined by averaging the 

night's samples. Variability in heart rate was 

obtained by computing the standard deviation 

o:f the heart rate :for the 100 samples. 

Measures of Responses to the Booms. ECG 

responses to a boom were measured by determining heart rate one minute before and one minute 

after a boom presentation. 

Muscle Tone (Ell/G) 

All-Night Measures. Muscle tone as recorded 

on an integrated EMG channel was measured 

by ruler in terms o:f both absolute level and 

variability during the night. EMG levels were 

scored every five minutes (unless there was an 

artifact or an arousal lasting less than 10 seconds, 

in which case the last "normal" recording was 

used); each score was the level o:f EMG measured at the end o:f a five-minute period. Because 

o:f the (normal) variability between nights, the 

first EMG recording o:f each night was given a 

reading o:f zero, and all subsequent recordings 

o:f the night were measured as deviations :from 

that level. The overall level o:f EMG was averaged :for each o:f nine periods o:f that night. The 

first period consisted o:f the initial 20 minutes o:f 

the night, and the subsequent eight periods were 

each an hour long. The variability o:f the EMG 

was obtained by computing the standard deviation o:f the 100 EMG readings made each night. 

Measures of Responses to the Booms. The 

percentage o:f boom presentations resulting in any 

measurable EMG response within five seconds 

was determined as well as the percentage o:f boom 

presentations showing recovery within ten minutes. In addition, these measures were also obtained :from the EMG recording 30 minutes 

prior to an actual boom presentation. These 
Table 6 

The Williams Criteria for Scoring EEG Tracings (Adapted from Lukas and 

Kryter, 1968). These Scores Are Not Independent Since a High Score 

Usually Includes All the Lower Scores, e.g., a Williams Score of 

Williams 

Score 

0 

1 

2 

3 

4 

5 

6 

7 

Three Indicates That K Complexes Also Occurred. 

Change Required on EEG Record 

No change. 

A K complex of low amplitude (less than 150 microvolts) 

which occurs within one second after boom presentation, 

but is usually coincidental with the boom. 

A K complex of high amplitude (above 150 microvolts) or 

several K responses which occur within two seconds of 

termination of the boom stimulus. 

The presence of an Alpha pattern or synchronization within 

two seconds of termination of the boom stimulus 

Body movement or movement of facial or eye muscles within 

six seconds of termination of the boom stimulus. 

A one-step shift in sleep stage (e.g., from a Stage 3 to 

a Stage 2) within one minute of termination of the boom 

stimulus. 

A two-step shift in sleep stage (e.g., from a Stage 4 to 

a Stage 2) within one minute of termination of the boom 

stimulus. (This score was not assigned since we used a 

combined Stage 3-4 and a shift of two stages resulted in 

awakening.) 

Prolonged Alpha movement and an Awake response within one 

and one-half minutes of termination of the boom stimulus. 

(The delay was recommended for studies which require the 

subject to signal his awareness of being awake; it allows 

time for the subject to find the signalling device.) 

data served as the pseudo stimulus control condition to compare with changes resulting from 

an actual boom presentation. 

subjects on the initial BSR level for a night 

(differences greater than might be expected due 

to the boom), the first BSR recording was given 

the value of zero ohms. All subsequent measures 

were computed as deviations from the original 

level. Also, any two-minute epoch which contained a balance change (i.e., a shifted baseline) 

was omitted because of difficulty determining the 

appropriate BSR level. The mean BSR level 

was obtained for each of nine periods during the 

night. The first period was the initial 20 minBasal Skin Resistanoe (BSR) 

All-Night Measures. The BSR was measured 

in terms of both absolute level and variabilitv 

during the night. BSR was scored every tw~ 

minutes except >vhen a movement artifact occurred at that point; in this case, the last "normal" BSR recording was taken. Because of the 

large (normal) variability between and within 

9 
utes of the night, and the next eight periods 

were each an hour long. The variability of the 

BSR was computed by calculating standard 

deviations for each night. 

Measures of Responses to the Booms. To evaluate the effect of the sonic boom on BSR, five 

dependent measures were used : ( 1) percentage 

of boom presentations showing any measurable 

change in BSR within five seconds of boom onset, (2) magnitude of response in kilohms, (3) 

latency of responses, ( 4) percentage of responses 

showing recovery within ten minutes, and ( 5) 

latency of recovery for those responses which 

returned to pre-boom levels within ten minutes. 

III. Results and Discussion. 

Sleep Profiles 

Patterns of Sleep. The EEG scores obtained 

during the Baseline phase for time awake, movement time, and four stages of sleep are presented 

in Figure 4 and compared with data from Lukas 

(1970) and from Kramer, Roth, Trindar, and 

....... 

(/) 

<t 

~ 

:::::> 

...J 

>- ID 

Cl 

IJJ 

0:: 

0 

u 

(/) 

b 

z 

MOVEMENT 

DURING SLEEP 

STAGE 

I 

Cohen ( 1970). In general, the sleep patterns 

obtained in this study are similar to those reported by Lukas ( 1970) and by Kramer et al. 

(1970). 

Table 7 presents percentages reflecting the 

average amounts of time the subjects in each age 

group spent in the four stages of sleep, in being 

awake, and in movement during sleep for Baseline, Boom, and Recovery phases, respectively. 

Analyses of variance conducted on these scores 

for each of these six aspects of sleep indicated 

no significant differences at the .05 level among 

the three phases. Thus, presentation of the 

booms had no significant effect on the proportion 

of time spent in any of the sleep stages. However, significant differences were obtained 

(p<.01-p<.001) among the age groups for five 

of the six sleep stages (Stage 3-4 was the exception) indicating that the proportion of time 

spent in one sleep stage or another was related 

to age but not to presentation of the boom 

(specifically, the sleep pattern of the oldest group 

accounted for most of these differences). 

STAGE 

2 

KRAMER, et al. 121 

LUKAS • 

PRESENT 0 

STAGE 

3-4 

STAGE 

REM 

STAGES OF SLEEP 

FIGURE 4. A comparison of the percentages of time scored as movement time during sleep and as sleep stages 1, 2, 

3-4, and REM for the present study (based on three Baseline nights), for a 1971 study by Kramer, Roth, 

Trindar, and Cohen (based on two Control nights), and as approximated by Lukas (1970) for normal sleep 

(Lukas did not include an estimation of movement time during sleep). 

10 
Table 7 

Mean Per Cent of Night (500 Minutes) in the Various Stages of Sleep 

and Wakefulness for Baseline, Boom, and Recovery Nights 

Stages of Sleep 21-26 Year Olds 40-45 Year Olds 60-72 Year Olds 

Base line Boom Recovery Baseline Recovery Baseline Recovery 

Total Time Awake 

Movement Time 

During Sleep 

Sleep Stage 1 

Sleep Stage 2 

Sleep Stage 3-4 

6.6 

2.2 

5.3 

44.9 

19.0 

8.0 11.1 10.9 

2.2 2.4 1.6 

5.2 5.2 9.4 

45.4 44.9 40.3 

18.0 16.5 16.3 

9.2 

1.3 

8.7 

40.4 

18.1 

7.9 

1.3 

9.3 

42.0 

17.3 

18.2 

1.5 

7.5 

34.6 

21.8 

16.9 

1.4 

8.1 

35.3 

20.2 

16.2 

1.4 

8.4 

36.8 

20.1 

Sleep Stage REM 22.0 

Total i:OD.i) 

21.2 

100.0 

19.9 

100.0 

21.5 

wo:o 

22.3 

'i'ii'Q.(i 

22.2 

100.0 

16.4 

100.0 

18.1 

100.0 

17.1 

100.0 

The distribution of time awake during the 

night, the latency for onsets of Stage 2 and of 

Stage REM, and the number of changes in sleep 

stages during the night are presented by age 

group in Table 8 for Baseline, Boom, and Recovery nights. Analyses of variance of these 

Table 8 

scores yielded no significant difference at the .05 

level across the three phases. Thus, these sleep 

profiles showed no effects which could be attributed to the boom presentations. Significant 

differences which were obtained among the age 

groups for spontaneous time awake (p<.OOl), 

Distribution of Time Awake (in Minutes), Mean Number of Sleep Stage Alternations, and Mean 

Latencies (in Minutes) to Stages 2 and REM for Baseline, Boom, and Recovery Nights 

Measures 

Minutes Awake 

Before Sleep 

Minutes Awake 

During the Night 

Minutes Awake 

After Sleep 

Minutes Latency 

to Stage 2 

Minutes Latency 

to Stage REM 

No. of 30-Second 

Stage Changes 

No. of 5-Minute 

Stage Changes 

No of 10-Minute 

Stage Changes 

21-26 Year 01ds 

Base line !!.22!!! Recovery 

21.9 27.0 27.9 

8.0 12.1 15.4 

3.1 0.4 1.8 

14.2 16.4 20.4 

60.0 66.1 78.3 

63.6 64.8 63.9 

10.5 10.6 10.3 

8.1 7.9 7.3 

Age Groups 

40-45 Year Olds 60-72 Year Olds 

Baseline Recoven Baseline 

24.0 21.2 19.3 25.2 24.1 

24.1 19.9 15.2 52.3 51.6 

6.7 4.6 3,4 13.3 9.7 

15.0 11.8 14.0 13.0 

62.1 54.7 49.9 52.9 54.2 

62.3 65.2 64.5 72.1 69.3 

13.5 13.1 12.7 15.5 15.5 

9.5 9.8 9.7 10.0 10.6 

11 

Recovery 

25.3 

47.8 

7.7 

14.1 

53.4 

69.7 

15.3 

10.5 
latency to Stage REM (p<.01), and shifts in 

sleep stages using 5-minute and 10-minute time 

bases (p < .001 in both cases) reflect differences 

in sleep patterns with age and are independent 

of the presence or absence of the booms. Similarly, statistically significant interactions (age 

groups by the three phases) obtained for the 

latency scores for both Stage 2 (p< .001) and 

Stage REM (p<.01) reflected no effects of the 

boom presentations but, rather, increased latencies for the youngest age group from the Baseline through the Boom through the Recovery 

phases. 

Awakenings. The frequencies with which 

awakenings occurred during the night were calculated from the tracings for Baseline, Boom, 

and Recovery phases. These data appear in 

Table 9 and show a fractionally higher incidence 

of awakenings during boom nights for all groups. 

However, an analysis of variance yielded only 

one significant effect (p < .01), viz., with respect 

to age. As is evident in Table 9, the frequency 

of awakenings increased with age, but no effect 

on awakenings can be attributed to the booms. 

It should be noted that these data do not represent behavioral awakenings, i.e., subjects were 

not required to signal their awareness of being 

awake. Instead, the data represent awakenings 

as indicated by the physiological tracings; as 

such, the periods scored as "awake" might be as 

short as 30 seconds and might never be recalled 

by the subjects on the following morning. Moreover, the occurrence of age differences in awakenings is well known (e.g., Kramer et al., 1971; 

·williams, 1970) and the oldest subjects used in 

this study recalled more awakenings during 

sleep at home than did the younger groups (see 

Table 3). 

EEG Changes in Response to Booms. The 

eight-point scoring criteria established by Williams were used to make direct comparisons of 

EEG responses to the booms with responses to 

periods of pseudo stimulus controls (i.e., to periods of sleep 30 minutes prior to presentation 

of a boom) . From these comparisons, presented 

in Table 10, it can be determined that, while 74.2 

per cent of the booms produced an EEG response 

(i.e., a non -zero \V"illiams Score), only 36.2 per 

cent of the control periods showed an EEG 

change. 

:More "zero" and "1" scores were obtained in 

control periods and more "2" through "7" scores 

were obtained in response to the booms; these 

differences were significant by chi square analysis 

at the .01 level. Although statistically significant, these changes must be considered moderate 

since boom presentations produced awakenings 

only 5.5 per cent of the time (compared with 

0.7 per cent for non-boom controls) and resulted 

in shifts in stages of sleep only 14.3 per cent of 

the time (compared with 4.2 per cent for nonboom controls). 

Age. Chi square analysis of the data in Table 

10 yielded a significant difference (p<.01) in 

EEG responses as a function of the age groups. 

This difference is due primarily to more frequent 

responses at the higher scores ("5" and "7") in 

the oldest group. The two youngest groups 

showed more "O" and "2" scores, and fewer scores 

of "5" (shift in stage of sleep) and "7" (awakening) than did the oldest group. 

Table 9 

Mean Frequency of Awakenings Per Night for Each Subject by Age Group. 

for Baseline, Boom, and Recovery Nights 

Nights 

Age Groups Baseline Boom Recovery Mean 

21-26 Year Olds 1.7 1.8 1.7 1.7 

40-45 Year Olds 3.3 3.7 3.1 3.4 

60-72 Yeat' Olds 5.5 5.9 5.1 5.5 

Mean 3.5 3.8 3.3 

12 
Table 10 

Mean Frequency of Occurrence (in Percentages) of Each Williams Score in EEG Tracings 

Following Presentation of Booms and of Pseudo Stimulus Controls 

Age Groups _Q_ _1 _ 

21-26 Year Olds 

Boom 28.0 4.6 

Pseudo Stimulus Control 69.0 8.2 

40-45 Year Olds 

Boom 27.8 5.1 

Pseudo Stimulus Control 61.7 5.8 

60-72 Year Olds 

Boom 21.5 5.0 

Pseudo Stimulus Control 60.7 12.6 

All Ag_e Grou~s 

Boom 25.8 4.9 

Pseudo Stimulus Control 63.8 8.9 

Adaptation. To examine possible adaptation 

effects across the 12 boom nights, analyses of 

variance were performed on .. Williams Scores 

which occurred at least 10 per cent of the time 

following boom presentations; those scores were 

"O," "2," "4," and "5" (see Table 10). The percentage of EEG responses under each of the 

four scores is presented in Table 11 by age group 

for each boom night. No differences among the 

12 nights were significant at the .05 level for any 

score or age group by analyses of variance. Thus, 

there was no evidence in the EEG tracings of 

adaptation to the occurrence of the booms. 

Sleep Stage. That subjects might be more 

responsive to booms during certain stages of 

sleep ( cf., ·williams et al., 1964) was examined. 

Per cent responses for the four stages of sleep 

(REM and Stages 1 2 3-4) of "O" "2" "4" . ' ' ' ' ' and "5" scores (those scores which occurred at 

least 10 per cent of the time following booms) 

by the Williams Criteria are plotted in Figure 5 

for all subjects combined. Analyses of variance 

Williams Scores 

2 _3_ ..±._ _5_ ....L _7_ 

27.6 0.9 26.6 10.6 0.0 1.7 

13.1 o.o 6.0 3.4 o.o o.o 

14.9 6.6 25.8 13.7 0.0 6.1 

12.1 1.5 13.9 3.9 o.o 1.1 

14.0 6.4 25.8 18.6 0.0 8.7 

7.7 0.5 12.1 5.4 o.o 1.0 

18.8 4.6 26.1 14.3 o.o 5.5 

11.0 0.7 10.7 4.2 0.0 0.7 

13 

were performed (without collapsing the age 

groups) for each of the four Williams Scores. 

Results indicated significant (p<.05-p<.001) 

differential responsivity to the booms during 

certain stages of sleep. Specifically, Sleep Stage 

1 and Sleep Stage 2 yielded significantly fewer 

"O" scores and significantly more "4" scores following boom presentations than were obtained 

in control periods. This result is consistent with 

other studies (Lukas, 1972; Lukas and Kryter, 

1970b) and may be attributed to the fact that 

Stage 1 in particular is a transition phase between being awake and reaching the deeper sleep 

of Stage 2. Williams Scores of "2" and "5" 

showed different results; for these scores, Stages 

2 and 3-4 were most sensitive to the boom presentations.. The latter finding might be expected 

because the K complex, which defines a score of 

"2," and stage shifts, which define the score of 

"5," are much less likely to occur in REM or 

Stage 1 sleep as a function of the boom presentations (a noise-induced stage shift from REM or 
Table 11 

Mean Frequency of Occurrence (in Percentages) of Williams Scores of 0, 2, 4, and 5 

Following Boom Presentations During Each of the 12 Boom Nights 

Age Groues Boom Night_s 

_ 1_ _ 2 __ 3 _ _ 4 __ 5 _

21-26 Year 

01ds 

Score 

0 25.0 26.6 25.0 37.5 34.4 

2 32.8 26.6 28.1 23.4 18.8 

4 28.1 21.9 26.6 20.3 28.1 

5 12.5 6.3 9.4 9.4 12.5 

40-45 Year 

Olds 

Score 

0 17.2 23.4 28.1 17.6 20.3 

2 21.9 12.5 14.1 27.2 7.8 

4 20.3 35.9 29.7 29.0 26.3 

5 18.8 12.5 17.2 7.8 17.2 

60-72 Year 

Olds 

Score 

0 21.9 12.5 28.1 20.3 23.4 

2 10.9 8.0 12.5 4.7 23.4 

4 14.1 25.2 20.5 35.9 18.8 

5 18.8 24.1 14.7 15.6 17.2 

Stage 1 would most probably result in awakening and would thereby be scored as a "7"). 

Time-of-Night. Analyses similar to those 

noted above for sleep stages were conducted for 

time-of-night. For these purposes, each boom 

night ( 500 minutes) was divided into four quarters (results for all subjects combined are depicted in Figure 6) . No significant time-of -night 

differences between booms and control periods 

were obtained for Williams Scores of "2" and 

"5"; however, significant increases in sensitivity 

to the booms were obtained for "O" and "4" 

scores (p<.05 and p<.001, respectively). There 

were proportionately fewer "0" scores for boom 

periods during the first and third quarters of the 

night than were obtained for control periods, and 

proportionately more "4" scores following booms 

during the second and third quarters of the 

night. Although these data extend the periods 

of maximal sensitivity into the third quarter of 

the night, they are in general agreement with 

other studies (Kramer et al., 1971; Morgan and 

Rice, 1970; Rechtschaffcn et al., 1966; ·williams 

et al., 1964) which show that sensitivity to noise 

_ 6 _ _ 7 __ 8 _ _9 _ ...l!L.. _lL _!L 

21.8 31.6 32.4 23.4 33.0 21.9 28.1 

23.4 28.1 31.0 26.6 27.5 31.3 30.0 

34.4 26.6 20.5 31.3 35.2 23.4 31.3 

12.5 9.4 11.4 10.9 12.4 14.1 7.8 

23.4 29.7 34.4 33.9 34.4 28.1 34.4 

12.5 14.1 17.2 14.3 10.9 12.5 14.1 

23.4 26.6 25.0 19.0 31.3 21.9 23.4 

12.5 15.6 10.9 13.6 12.5 17.2 7.8 

20.3 17.2 35.9 21.0 16.3 19.4 20.96 

10.9 17.2 14.1 20.8 17.8 12.9 14.28 

28.1 29.7 21.9 21.0 33.7 27.0 33.46 

17.2 18.8 17.2 27.5 17.4 20.7 13.81 

14 

is greater during early rather than later periods 

of the night. 

Heart Rate 

Nightly Patterns. Table 12 contains the means 

and standard deviations for number of heart 

beats per minute for each age group during 

Baseline, Boom, and Recovery nights. Analyses 

of variance were performed on both of these sets 

of data. Only one significant difference was obtained (p<.05): the age groups differed on mean 

heart rate. Thus, although the oldest subjects 

had significantly higher heart rates than the 

younger men, introduction of the booms produced no overall change in heart rate measures 

for any group. 

ECG Changes in Response to Booms. The 

mean number of heart beats was calculated by 

age group, during each boom night, for periods 

one minute before and one minute after the pre· 

sentation of each boom; these pre-boom and postboom data appear in Table 13. Analysis of 

variance indicated that there was a significant 

increase (p< .05) in heart beats after boom presentations for all subjects across all nights. 
zl() 

-a:: 

oO 

80 

w v 60 1- • .....J(\J 

:::> • <1>0 

w lL. 40 

0:::0 

<f>w 

~0::: 

0 0 20 Ou 

CD<f> 

<I> a.. Ww 

~w 

i=.....J (f) 

LL.(f) 

0~ 

1-c:t Zw.....J 

u:::! 

o::3: 

w 

ll.<t 

40 

20 

REM I 

REM I 

80 

60 

2 3-4 

40 

2 3-4 

TRIALS 

........ sooM 

o-oCONTROL 

SCORE 2 

REM I 2 3-4 

REM I 2 3-4 

STAGES OF SLEEP 

FIGURE 5. Frequencies of occurrence in percentages of 

Williams Scores of 0, 2, 4, and 5 following boom 

presentations in different stages of sleep. 

However, there was no main effect attributable 

to age and there was no adaptation evident. 

Muscle Tone 

Nightly Patterns. Each test night was divided 

into nine periods (the first 20 minutes of the 

night and the next eight hour-long segments) 

and muscle tone (EMG) was scored in 5-minute 

blocks. The measure for the first 5-minute block 

was assigned a score of "zero" and all subsequent 

blocks were scored as deviations from that "zero"; 

these data on muscle activity are, therefore, in 

arbitrary units. Table 14 contains mean levels 

of muscle tone by age group for the nine periods 

of the night for Baseline, Boom, and Recovery 

phases. An analysis of variance of these data 

yielded only one significant effect (p<.001), viz., 

for period-of-night. This result is accounted for 

by a general decrease in level of muscle tone 

during most of the night. A sharp drop during 

the first period (first 20 minutes) may be at· 

tributed to the decrease of muscle tone which 

accompanies the onset of sleep; further declines 

during the next several hours probably reflect 

15 

increasing concentrations of REM sleep in which 

low levels of EMG activity would be expected, 

then, during the last two hours, level of muscle 

tone increases as the end of the sleep period 

nears. There were no significant differences 

among age groups or across the Baseline, Boom, 

and Recovery nights. 

A second measure of muscle activity appears 

in Table 15 where the mean variability (standard 

deviations of EMG scores) for Baseline, Boom, 

and Recovery nights is presented for each age 

group. An analysis of variance of these data 

showed only one significant effect (p< .05), viz., 

a steady overall increase in variability of muscle 

tone levels across the experimental conditions. 

This finding does not appear to be related to 

boom presentations since variability continued to 

increase during the Recovery nights when booms 

were no longer being presented. There were no 

significant differences among the age groups although the oldest group showed a slight decline 

in EMG across the three phases. 

zl() 

-c:: 

oo 

Woq-

~ . ::J(\J 

(f) • 

wo 

o::Li.. 

(f)o 

~w 

00:: 

00 

CDU 

(f) (f) 

wa.. 

~w 

-W 

1-.....J 

80 

60 

40 

20 

Li.. (f) 40 

O(f) 

~--~ 

z<t 

wu .....J 20 .....J 

o::- w3: 

a..<t 

SCORE 

~ 0 

/ 

2 3 4 

SCORE 4 

~ 

~ 

2 3 4 

80 

60 

40 

20 

40 

20 

TRIALS 

........ aooM 

o-oCONTROL 

SCORE 2 

' 2 3 4 

SCORE 5 

~ 

~ 

2 3 4 

QUARTER OF THE NIGHT 

FIGeRE 6. Frequencies of occurrences in percentages of 

Williams Scores of 0, 2, 4, and 5 following boom 

presentations in different quarters of the night. 
Table 12 

Mean Number of Heart Beats Per Minute and Mean Standard Deviations for Each Subject 

by Age Group for Baseline, Boom, and Recovery Nights. Note: These Values Are 

Slightly Higher Than Those in Table 13 (One-Minute Pre and Post Boom) Due to 

the Fact That These Scores Include Heart Rate During A~ake Stages Whereas 

Subjects Were Virtually Always Asleep When Booms Were Presented. 

Nights 

Age GrOUES Baseline Boom Recover:t: 

21-26 Year Olds 

Beats Per Minute 63.6 62.4 64.9 

Standard Deviation 3.8 2.7 2.9 

40-45 Year Olds 

Beats Per Minute 62.4 62.0 63.1 

Standard Deviation 3.5 2.9 3.0 

60-72 Year Olds 

Beats Per Minute 69.7 68.9 68.4 

Standard Deviation 2.8 3.2 3.0 

Table 13 

Mean Number of Heart Beats One Minute Before and One Minute After 

Boom Presentations for Each of the 12 Boom Nights 

Boom Nights 

Age Groups _1_ ..1.... _L ...L ..L ..!... _7_ ...L _9_ ....!.Q_ ....!L ....!L ~ 

21-26 Year Olds 

Before Boom 59.3 60.8 59.2 60.7 60.7 59.1 60.4 61.1 61.2 60.5 59.5 59.9 60.2 

After Boom 60.2 59.3 60.3 62.2 61.8 59.8 60.6 61.5 61.3 61.6 60.2 60.4 60.8 

40-45 Year Olds 

Before Boom 61.5 61.1 60.9 62.7 61.9 60.6 62.7 62.8 60.2 60.5 61.3 61.6 61.5 

After Boom 61.3 63.7 61.3 62.8 61.3 61.8 63.3 62.6 62.0 60.4 62.1 61.8 62.1 

60-72 Year Olds 

Before Boom 65.4 64.9 64.2 65.0 66.4 66.0 64.3 65.7 63.5 64.8 63.9 61.9 64.7 

After Boom 65.4 66.3 65.0 66.0 67.2 66.4 65.4 66.1 65.8 65.2 65.1 61.8 65.5 

16 
Table 14 

Mean EMG Levels During the Nine Periods of the Night for Baseline, Boom, and Recovery Nights 

All 

Period 21-26 Year Olds 40-45 Year Olds 60-72 Year Olds Ages 

of the 

Night Baseline Boom RecoVer! Mean Baseline Boom 

1 -0.14 -0.26 -0.19 -0.20 -0.28 -0.35 

2 -1.13 -1.17 -0.91 -1.07 -1.14 -1.21 

3 -1.58 -1.52 -1.22 -1.44 -1.50 -1.78 

4 -1.75 -1.75 -1.42 -1.64 -1.62 -1.90 

5 -1.87 -1.77 -1.40 -1.68 -1.68 -2.00 

6 -1.63 -1.58 -1.47 -1.56 -1.75 -2.07 

7 -1.86 -1.90 -1.60 -1.79 -1.65 -2.03 

8 -1.80 -1.55 -1.61 -1.65 -1.72 -2·.oo 

9 -1.86 -1.47 -1.54 -1.62 -1.55 -1.94 

Mean -1.51 -1.44 -1.26 -1.43 -1.70 

EJl!G Changes in Response to Booms. Comparisons were made o:f changes in EMG level in 

response to the booms and changes in muscle 

tone :following the pseudo stimulus control periods ( 30 minutes prior to a boom). Scores 

reflecting the mean percentage o:f times changes 

occurred in EM:G levels during the six seconds 

following the booms or the pseudo stimulus controls are presented in Table 16 by age group :for 

each Boom night. An analysis o:f variance performed on these data yielded two significant 

effects; there was more :frequently a change 

(p<.001) in EMG levels in response to the 

booms as compared with the control periods, and 

there were differences (p < .05) in the overall 

frequency of changes attributable to age. The 

significant effect o:f age is due primarily to the 

greater proportion of EMG changes which occurred in the oldest age group. In evaluating 

the significant changes in EMG levels attributable to the booms, it should be noted that all 

EMG levels returned to their Baseline values 

within ten minutes of any change due to the 

booms. The lack of any other significant effects 

:from the statistical tests indicates no evidence o:f 

adaptation across the 12 Boom nights. 

Basal Skin Resistance 

Nightly Patterns. Mean BSR levels were 

computed :for each o:f nine periods o:f the night 

17 

Recoven: Mean Baseline Boom R~coven: ~ Mean 

-0.47 -0.37 -0.25 -0.23 -0.34 -0.27 -0.28 

-1.24 -1.20 -1.25 -1.42 -1.38 -1.35 -1.21 

-1.69 -1.66 -1.76 -1.94 -2.08 -1.93 -1.67 

-1.74 -1.75 -1.38 -2.03 -2.31 -1.91 -1.77 

-1.89 -1.86 -1.50 -2.04 -2.14 -1.89 -1.81 

-1.99 -1.94 -1.30 -2.00 -2.05 -1.78 -1.76 

-1.76 -1.80 -1.45 -1.95 -2.14 -1.85 -1.81 

-1.81 -1.84 -1.34 -1.96 -1.92 -1.74 -1.75 

-1.50 -1.66 -1.08 -1.66 -1.59 -1.44 -1.58 

-1.57 -1.26 -1.69 -1.77 

(the first 20 minutes and the following eight 

hour-long segments) and are presented by age 

group for Baseline, Boom, and Recovery nights 

in Table 17. An analysis of variance of these 

data yielded three significant main effects and 

no significant interactions. The statistically significant effect (p<.05) for age groups is accounted for by the consistently lower level of 

skin resistance during all periods and across all 

conditions for the youngest subjects (in this 

instance, absolute differences among the groups 

may be attributed at least partially to differences 

in amplifier gain settings). The significant increase (p<.001) in BSR across the nine nightly 

periods reflects an expected decrease in skin resistance for all subjects during the course of the 

night. Finally, significant differences (p<.01) 

in BSR scores among the Baseline, Boom, and 

Recovery nights is accounted for by a steady 

decrease in skin resistance (signifying increased 

arousal) across the three experimental conditions. However, since skin resistance continued 

to decline during the Recovery (non-boom) 

nights, the effect cannot be related to boom 

presentations. 

Variability in BSR levels was examined by 

using standard deviations. These mean variability measures by age group for the Baseline, 

Boom, and Recovery nights are presented in 

Table 18. An analysis of variance of these data 
Table 15 

Mean Standard Deviations of EMG Levels for 

Baseline, Boom, and Recovery Nights 

Age GrouE! Baseline 

21-26 Year Olds 0.76 

40-45 Year Olds 0.61 

60-72 Year Olds 1.03 

Mean 0.80 

indicated two significant effects (p < .05), viz., 

for phases and for the interaction of age groups 

and phases. The latter finding was due to the 

different patterns of variability across the Baseline, Boom, and Recovery nights for the three 

age groups. Specifically, the two oldest groups 

showed steadily decreasing variability, while the 

youngest group had an irregular pattern (see 

Table 18). Despite these differences in pattern, 

Nights 

~ Recovery 

0.90 1.39 

0.82 1.00 

1.01 0.98 

0.91 1.12 

the significant overall phase effect indicates that, 

across all subjects, variability declined from the 

Baseline through the Boom and Recovery phases 

(Table 18). 

BSR Changes in Response to Booms. To 

assess the effects of the booms on skin resistance, 

five BSR measures were computed: (1) the percentage of occasions during which a change in 

BSR occurred within five seconds of boom preTable 16 

Mean Percentage of Times EMG Responses Occurred to 

Boom Presentations and to Pseudo Stimulus Controls 

Boom Nights 

Ase Grou2s _1_ _ 2_ _3 _ ..!L _ 5_ ....§_ _7 _ _a_ ...2.... _!Q_ ...lL ...!.L ~ 

21-26 Year Olds 

Boom Presentation 43.7 34.4 39.1 42.2 43.7 47.6 .45.3 43.1 46.9 38.0 32.8 40.6 41.5 

Pseudo Stimulus 

Control 9.4 12.5 10.9 7,8 3.1 12.5 15.6 10.9 10.9 7.8 7.8 12.5 10.1 

40-45 Year Olds 

Boom Presentation 56.4 40.6 43.8 40.6 40.6 31.3 45.3 50.0 31.3 45.3 51.6 39.1 43.0 

Pseudo Stimulus 

Control 14.0 15.6 6.3 10.9 17.2 9.4 21.9 17.7 20.3 7.8 17.2 12.5 14.2 

60-72 Year Olds 

Boom Presentation 51.6 73.4 53.8 59.4 43.8 60.9 60.9 62.5 53.1 68.8 59.6 49.1 58.1 

Pseudo S t imu1us 

Control 26.6 17.2 23.4 18.8 17.2 12.5 17.2 18.8 18.8 18.8 17.4 17.2 18.7 

18 
Table 17 

Mean BSR Levels (in Kilohms) of the Nine Periods of the Night 

for Baseline, Boom, and Recovery Nights 

Age Groups 

21-26 Year Olds 40-45 Year Olds 60-72 Year Olds 

Period of 

the Night Baseline ~ Recover:t Baseline 

1 2. 71 2.16 0.23 8.30 

2 3.34 3.18 1.30 16.90 

3 3.59 3.88 1.92 19.65 

4 3.98 4.44 2.23 19.41 

5 4.50 4.64 2.55 21.36 

6 4.91 5.07 3.04 25.33 

7 5.12 5.37 3.11 23.05 

8 5.55 5.54 3.36 23.65 

9 5.68 5.67 3.42 25.25 

sentations, (2) the magnitude of those changes 

in kilohms, ( 3) the latency of the changes in 

seconds, ( 4) the percentage of responses which 

showed recovery to the base level ;vithin ten 

minutes, and ( 5) the latency of recovery in seconds. The overall mean calculated for each of 

those five measures appear in Table 19. Disregarding age, a change in BSR level occurred 

within five seconds for 19.4 per cent of the booms, 

the mean latency for those occurrences was 3.2 

seconds, and the mean change in BSR level was 

~ Recover:t Baseline Boom Recover:t 

9.37 5.81 8.29 8.96 7.45 

12.29 6.89 10.41 10.03 8.70 

13.13 7.25 10.43 10.15 8.58 

13.81 7.50 11.07 10.59 9.04 

14.19 7.65 11.60 11.01 9.55 

14.81 7.98 11.84 11.24 9.93 

15.24 8.07 11.97 11.79 10.10 

15.93 8.30 12.20 12.30 10.35 

15.46 8.72 12.75 13.08 10.54 

-5.0 kilohms. Recovery to pre-boom BSR levels 

occurred within ten minutes for 51.0 per cent of 

the boom-induced changes and, of these 51.0 per 

cent, the mean latency for recovery was 47.9 

seconds. 

Only two age-related tendencies appear in the 

data in Table 19. The percentage of BSR responses to the booms increased slightly (but not 

significantly) from the youngest to the oldest 

age group, and the mean amount of change in 

BSR level was successively higher for the adTable 18 

Mean Standard Deviations of BSR Levels for 

Baseline, Boom, and Recovery Nights 

Nights 

Age Groups Baseline Boom Recovery 

21-26 Year Olds 4.07 5.99 4.61 

40-45 Year Olds 14.64 9.19 6.35 

60-72 Year Olds 11.78 10.44 9.92 

Mean 10.16 8.54 6.96 

19 
vanced age groups. However, analyses of variance conducted for each of the five BSR measures yielded only one significant effect (p < .05) : 

the youngest subjects showed less change to the 

booms in BSR level than did either of the two 

older groups of subjects. The lack of any other 

statistically significant effects indicates that there 

was no adaptation of BSR responses to the 

booms across the 12 Boom nights. 

Mood States 

The 80-item Composite Mood Adjective Check 

List ( CMACL) was administered every morning 

and every evening during the study. Scores 

ultimately derived for 15 mood factors and an 

overall mood index were treated by analysis of 

variance. More detailed analyses 6£ these findings appear elsewhere in a report by Smith and 

Hutto (1972). 

A mean Overall Index of mood (based on all 

CMACL items) was calculated for morning and 

evening sessions for each age group in the Baseline, Boom, and Recovery phases (see Table 20). 

In general, the oldest group had the highest 

mood levels (most positive affect) and the overall (all subjects) mood level declined across 

Baseline, Boom, and Recovery phases. Successive phases differed significantly (p<.05) from 

each other and, since the decline in mood .continued through the Recovery phase, the effects 

cannot be attributed to the booms. In fact, this 

mood loss is accounted for primarily by a steady, 

marked decline within the youngest age group, 

a decline which may be related to the fact that 

the youngest group was the only one which 

showed increasing amounts of total time awake 

across the Baseline, Boom, and Recovery phases 

(see Table 7). 

Scores obtained for the 15 individual mood 

factors appear in Table 21. There were several 

factors (Concentration, Dizzy, Friendly, Nonchalance, and Social Affection) which showed 

significant (p < .05) age effects; in all cases the 

oldest group had the highest scores. There were 

significant time-of-day effects (p<.05-p<.01), 

which favored evening scores, for only two factors: Surgency and Depression. Seven factors 

showed significant phase effects (p<.05-p<.001); 

six of these (AACL, Concentration, Friendly, 

Social Affection, Surgency, and Vigor) showed 

some overall tendency for a decline in moods 

(although only for Concentration and Vigor 

were the changes consistent for the three groups) , 

while the other factor (Sleepy) showed a general 

improvement across Baseline, Boom, and Recovery nights. The finding with respect to Sleepy 

scores is of particular interest since, (a) it shows 

no overall deleterious effects of the booms, (b) 

it agrees with results reported by Morgan and 

Rice ( 1970), and (c) in spite of the overall trend 

toward successively less sleepiness across the 

Baseline, Boom, and Recovery nights for all subjects considered together, the youngest group had 

its highest Sleepy score during Recovery nights 

when their time awake had noticeably increased 

(see Table 7). Perhaps young subjects adapt 

less well than do older subjects to the relatively 

long-duration social restrictions required by the 

present study. 

Table 19 

Measures of BSR Reapoa.ea to Boom Preaentationa for Each of the 12 Boom Ni&hta. Mean Value a Per Subject by Age Group for the Percentage of Boom 

Presentation~~ Which Showed BSB. Reaponaea 1 the Magnitude of Chana• in BSR Rupouea 1 the X.tenc::y of the Responses, the Percentage 

of Ruponaea Which Showed Recovery Within 10 Minutes, and the t.tency of Recovery for the Latter. 

Boom Nishta 

~ Ase Groue• _ 1_ _ 2 _ _ 3_ _ 4 _ _s _ _ 6 _ _ 7 _ _ 8_ _9 _ ....!L. _11_ _12 _ t!!.!!:L 

% of Booma 21-26 Year Olda 17.19 4.69 23.44 20.54 28.79 25.00 15.63 22.54 17.19 18.97 11.16 18.75 18.66 

Showing BSR 40-45 Year Olda 18.75 25.23 21.88 26.56 20.31 14.06 14.06 12.50 14.06 17.19 15.63 18.75 18.25 

Re9ponsea 60-72 Year Olda 27.61 29.69 22.10 24.11 16.75 15.63 16.96 25.00 18.30 20.09 24.79 14.06 21.26 

Change in 21-26 Year Olda • 2.78 0.47 • 1.88 - 2.95 - 1.19 • 2.38 • 1.48 • 7.28 - 4.31 • 3.63 • 2.94 • 4.38 - 2.89 

BSR Respon1e 40-45 Year Olda . l. 76 • 6.23 • 6.13 - 7.39 - 4.98 • 6.00 • 2.66 • 1.64 - 5.15 ·1.71 • 4.80 • 4.25 • 4.39 

(Kilohms) 60-72 Year Olda - 7.96 ·10.29 - 8. 75 - 8.01 • 7.13 -12.04 • 5.00 ·11.45 • 6.25 • 4.29 • 8.34 - 3.83 - 7. 78 

Latency of 21-26 Year 01da 2.31 1.25 3.15 3.26 3.19 4.59 2.89 3.66 3.59 3.79 2. 75 3.54 3.16 

Response 40-4S Year Olda 2,20 3.95 4.54 3.23 2.46 3. 73 2.20 2.69 3.94 3.33 2.58 3. 79 3. 22 

(Seconds) 60-72 Year 01da 3.70 3.53 3.13 2.55 3.81 2.23 2,45 3.88 3.73 2,38 3.89 2. 24 3.12 

7o Responses 21-26 Year 01da 24.16 12.50 68.75 60.41 66.68 53.13 50.00 72.91 50.00 72.91 62.50 53.13 53.92 

Showing 10- 40-4S Year Olda 25.00 42.75 87.50 55.25 34.38 58.38 35.38 39.63 56.25 37.50 52.13 39.63 46.98 

Minute Recovery 60-72 Year 01de 43.75 47.18 55.21 38.34 58.34 47 .so 46.88 68.75 59.38 62.50 58.34 39.59 52.14 

Latency of 21-26 Year Olde 46.00 4.50 145.75 38.88 12C>.13 37.75 83.50 88.75 34.13 81.63 41.38 36.00 63.20 

10-Minute 40-4S Year Olde 23.23 48.28 140.25 74.41 9.91 29.69 46.56 39.04 30.19 11.60 35.81 17.85 42.23 

Recoveries 60-72 Year Olda 26,13 61.86 41.79 27.69 19.50 51.11 5.63 60.08 30.48 24.79 88.48 22.63 38.34 

(Seconds) 

20 
Table 20 

Mean Overall Index Scores Per Subject for the Composite Mood Adjective Check List 

by Age Group for Morning (A.M.) and Evening (P.M.) Sessions 

During Baseline, Boom, and Recovery Nights 

Age Groups 

21-26 Year Olds 

40-45 Year Olda 

60-72 Year Olda 

All Age Groups 

A.M. 

P.M. 

Mean 

A.M. 

P.M. 

Mean 

A.M. 

P.M. 

Mean 

A.M. 

P.M. 

Mean 

Eleven of the 15 factors showed a significant 

interaction (p<.05-p<.001) for age groups and 

phases. Among the consistent results ~which 

produced these significant effects were (a) the 

decreasing scores (less positive affect) across all 

three phases in five factors (Friendly, Nonchalance, Social Affection, Surgency, and Vigor) 

for the youngest age group, in one factor (Vigor) 

for the 40-45 year olds, and in three factors 

(Sleepy, Surgency, and Vigor) for the oldest 

group, and (b) the increasing scores across all 

three phases in three factors (AACL, Anxiety, 

and Fatigue) for the youngest subjects, in one 

factor (Dizzy) for the 40-45 year olds, and in 

one factor (Social Affection) for the oldest group 

(see Table 21). None of these effects are boomrelated. 

Complex Performance 

Mean scores for the ten measures of performance were calculated for morning and evening 

sessions for each age group in the Baseline, 

Boom, and Recovery phases (see Table 22). Each 

measure was separately treated by analysis of 

variance. More detailed analyses of these data 

are reported elsewhere by Chiles and ~West 

(1972). 

Nights 

Baseline Boom Recover! 

21 

6.99 6.82 6.54 

6.97 6.83 6.26 

6.98 6.82 6.4o 

7.00 6.82 6.93 

1.:..Q2. 6.79 6.84 

7.05 6.80 6.88 

7.50 7.46 7.44 

~ 7.63 7.47 

7.53 7.55 7.45 

7.16 7.03 6.97 

7.21 1..:.M 6.86 

7.19 7.06 6.92 

Red Lights I and II. Response time for Red 

Lights I differed for age groups, phases, and 

time-of-day (all p<.05); a significant interaction 

(p<.05 and p<.001) was obtained for both I and 

II measures for age groups by phases. The significant effects which were obtained can be accounted for by the following: performance was 

better in the evening than in the morning, the 

two younger groups were significantly faster 

than the oldest group during Baseline trials, and 

the oldest group improved significantly during 

Boom and Recovery phases. None of these effects can be attributed to the booms. 

Green Lights I and II. Significant effects 

were obtained for both measures for age groups 

(p<.01), phases (p<.001), and the age groups 

by phases interaction (p<.01 and p<.001). In addition, time-of-day was significant (p< .05) for 

the Green Lights I measure. In general, these 

findings reflect quicker response from the younger 

groups, significant improvement across phases 

for the oldest group, better performance in the 

evening, and no deleterious effect of the booms. 

111 eter 111 onitoring I and II. A significant 

phase effect (p < .05) was obtained for Monitoring I due to the improved performance of all 

groups during Recovery nights as compared with 
Table 21 

Mean Scores Per Subject for Each of 15 Factors in the Composite Mood Adjective 

Check List by Age Group for Morning (A.M.) and Evening (P.M.) Sessions 

During Baseline, Boom, and Recovery Nights 

Baseline Boom Revovery 

Mood Age Groups 

Factor !Years} ~ ~ Mean ~ ~ ~ ~ ~ Mean 

*AACL 21-26 60.50 58.96 59.73 63.09 64.18 63.64 69.22 74.28 71.75 

(Zuckerman' a 40-45 59.17 57.96 58.56 64.22 64.12 64.17 62.31 62.44 62.38 

Affect Score) 60-72 49.79 49.46 49.62 50.50 47.02 48.76 50.47 50.59 50.53 

21-26 7.88 7.50 7.68 7.54 8.29 7.92 7.56 8.78 8.17 

Aggression 40-45 7.04 7.41 7.23 7.60 8.68 8.14 7.31 8.09 7.70 

60-72 7.17 6.75 6.96 7.48 6.88 7.18 7.75 7.66 7.70 

21-26 11.13 10.54 10.84 11.45 11.37 11.41 12.22 12.97 12.59 

Anxiety 40-45 11.78 11.33 11.56 12.19 12.07 12.13 11.84 11.88 11.86 

60-72 12.79 11.56 12.19 11.12 10.74 10.93 11.38 10.66 11.01 

21-26 1.46 1. 71 1.59 1.43 1.55 1.49 1.59 1.72 1.66 

Anxioua 40-45 1.42 2.25 1.83 3.36 2.85 3.11 3.47 3.12 3.30 

60-72 2.42 2.34 2.38 2.29 2.36 2.33 2.66 2.34 2.50 

21-26 39.17 38.67 38.92 34.60 34.93 34.77 31.03 30.03 30.53 

Concentration 40-45 39.35 41.33 40.35 40.00 38.46 39.23 39.56 36.97 38.27 

60-72 61.08 62.17 61.63 58.62 60.25 59.44 58.26 58.16 58.22 

21-26 23.63 28.59 26.11 25.94 26.03 25.98 28.25 33.09 30.67 

Depreasion 40-45 22.54 23.33 22.90 22.39 23.91 23.14 22.09 22.38 22.23 

60-72 23.33 23.50 23.42 21.58 20.81 21.20 21.28 21.91 21.59 

21-26 3.59 3.75 3.67 3.54 3.49 3.52 3.81 4.59 4.20 

Distrust 40-45 4.62 5.07 4.85 4.25 4.45 4.35 4.53 4.41 4.47 

60-72 4.42 4.58 4.50 4.85 4.84 4.85 4.69 4.66 4.67 

21-26 4.42 4.00 4.21 4.14 4.22 4.18 4. 75 5.94 5.34 

Dizzy 40-45 4.66 4.37 4.52 4.42 4.81 4.61 4.31 4.66 4.84 

60-72 7.67 6.38 7.02 6.68 6.54 6.61 6.84 6.44 6.64 

21-26 16.33 17.04 16.69 17.68 17.26 17.47 20.38 21.34 20186 

Fatigue 40-45 21.00 17.75 19.38 20.99 20.92 20.95 17.94 19.56 18.75 

60-72 26.12 24.47 25.30 24.49 21.88 23.18 24.22 22.84 23.53 

21-26 12.83 13.12 12.92 12.50 12.09 12.30 11.09 9.19 10.14 

Friendly 40-45 15.71 16108 15.89 12.97 13.17 13.07 13.97 14.03 14.00 

60-72 19.75 20.50 20.13 19.94 20.55 20.24 20.28 19.81 20.05 

21-26 6.29 6.96 6.62 6.07 6.23 6.15 5.75 5.78 5.76 

Nonchalance 40-45 8.25 8.25 8.25 6.38 6.69 6.54 6.84 7.2!1 7.05 

60-72 11.29 10.50 10.89 11.66 12.05 11.85 11.66 11.62 11.64 

21-26 7.21 7.8~ 7.52 7.06 7.08 7.07 8.94 9.06 9.00 

Sleepy 40-45 9.62 8.04 8.83 9.6.5 9.61 9.63 7.09 7.53 7.31 

60-72 13.52 14.08 13.77 12.68 10.75 11.71 11.19 10.81 11.00 

Social 21-26 16.83 17.58 17.07 16.73 16.44 16.58 15.12 12.72 13.92 

40-45 17.75 18.08 17.92 15.67 16.07 15.87 16.97 16.75 16.86 Affection 60-72 26.29 26.33 26.31 26.84 27.35 27.10 27.72 27.53 27.62 

21-26 21.58 23.17 22.37 20.02 19.89 19.95 16.38 15.47 15.92 

Surgency 40-45 21.87 23.08 22.48 19.65 20.26 19.95 21.66 20.78 21.22 

60-72 26.46 27.88 27.17 24.40 26.31 25.35 23.44 24,09 23.77 

21-26 15.46 15.33 15.40 13.46 13.39 13.42 11.12 10.69 10.91 

Vigor 40-45 14.95 15.59 15.27 14.09 13.93 14.01 14.28 13.66 13.97 

60-72 18.25 18.13 18.19 16.60 17.53 17.07 15.47 16.31 15.89 

"'For the AACL factor, higher acorea reflect leaa poaitive affect. 

22 
Table 22 

Mean Measures of Performance Per Subject on the CAM! Multiple Task 

Performance Battery by Age Group for Morning (A.M.) and Evening 

(P.M.) Sessions During Baseline, Boom, and Recovery Nights 

21-26 Year Olds 40-45 Year 01ds 60-72 Year Olds 

Base- Recov- Base- Recov- Base- RecovTask Time .!.!!!L ~ ery .!.!!!L ~ ery .!.!!!L ~ erv 

Red Lights I: A.M. 1.15 1.06 1.19 1.39 1.35 1.43 2.11 1.84 1.83 

Response Time P.M. 1.01 0.98 1.04 1.34 1.29 1.32 2.19 1. 74 1.65 

Mean 1.08 1.02 1.12 1.36 1.32 1.37 2.15 1. 79 1. 74 

Red Lights II: A.M. 1.07 1.08 1.22 1.49 1.62 1.51 1.84 1.46 1.34 

Response Time P.M. 1.03 1.01 1.24 1.39 1.57 1.56 1.88 1.52 1.40 

Mean 1.05 1.04 1.23 1.44 1.60 1.53 1.86 1.49 1.37 

Green Lights I: A.M. 2.49 2.26 2.49 3.86 3.29 2.93 6.04 5.12 4.76 

Response Time P.M. 2.14 1.99 1.97 3.64 3.27 3.18 5.90 4.75 3.91 

Mean 2.31 2.12 2.23 3.75 3.28 3.05 5.97 4.94 4.34 

Green Lights II: A.M. 2.24 2.07 2.20 3.39 3.33 2.94 5.89 4.30 3.62 

Response Time P.M. 2.09 1.72 2.06 3.67 3.12 3.11 5.73 3.99 3.37 

Mean 2.16 1.89 2.13 3.53 3.23 3.02 5.81 4.14 3.49 

Meters I: A.M. 14.00 8.65 8.73 10.27 9.83 7.47 13.17 11.09 8.69 

Response Time P.M. 13.41 7.88 8.45 10.14 13.70 7.24 12.20 9.88 9.38 

Mean 13.71 8.26 8.59 10.20 11.71 7.36 12.68 10.49 9.04 

Meters II: A.M. 13.63 8.04 8.79 13.44 9.11 9.16 12.94 12.57 7.93 

Response Time P.M. 7.38 7.96 6.43 11.94 22.07 8.46 12.11 8.50 7.64 

Mean 10.50 8.00 7.61 12.69 15.59 8.81 12.52 10.54 7.78 

Arithmetic I: A.M. 8.12 7.87 7.21 9.02 8.23 7.65 8.38 7.78 7.66 

Response Time P.M. 7.81 7.42 7.07 9.01 7.99 7.59 7.87 7.51 7.04 

Mean 7.96 7.64 7.13 9.01 8.11 7.62 8.12 7.64 7.35 

Arithmetic II: A.M. 87.87 94.96 95.37 89.48 94.54 95.28 87.98 89.65 90.42 

Per Cent Correct P.M. 84.21 95.90 96.57 92.92 94.99 96.60 92.81 93.97 96.97 

Mean 86.04 95.43 95.97 91.20 94.77 95.94 90.40 91.81 93.70 

Patteraa: A.M. 78.92 87.60 88.58 75.36 83.62 84.85 90.42 95.84 97.39 

Per Cent Correct P.M. 81.25 88.59 87.08 83.39 86.65 86.11 92.72 97.56 97.96 

Mean 80.08 88.09 87.83 79.37 85.13 85.47 91.56 96.69 97.67 

*Lights and Meters A.M. 39.80 41.37 40.60 37.73 38.28 39.08 32.87 35.81 37.33 

Composite P.M. 41.12 42.09 41.27 38.07 37.38 39.24 33.03 36.70 38.03 

Mean 40.46 41.72 40.94 37.90 37.83 3--9. 16 32.95 36.26 37.68 

*Higher scores indicate better performance. 

23 
Baseline nights. There were no effects attributable to the booms. 

Arithmetic Pe1' Cent Co?'?'ect and Arithmetic 

Time. Both measures yielded significant phase 

(p < .001) effects; in addition, time-of-day was 

significant (p<.05) for Arithmetic Time and a 

significant age group by time-of-day interaction 

(p<.05) was obtained for Arithmetic Per Cent 

Correct. In general, arithmetic performance 

improved for all groups across the Baseline, 

Boom, and Recovery phases and evening scores 

were better than morning scores. The booms 

produced no deleterious effects. 

Pattern Discrimination. Phases (p < .001) and 

age groups (p < .01) yielded significant effects 

in the percentage of patterns correctly discriminated. These significant F ratios are attributed 

to superior performance during Boom and Recovery nights as compared with the Baseline 

phase for all groups, and to more correct responses from the oldest group (the task had been 

made easier for the oldest group). 

Composite jJ{onitoring. Phases (p<.001), age 

groups (p<.05), time-of-day (p<.05), and the 

phase by age group interaction (p<.001) yielded 

significant F ratios. The oldest group performed 

significantly poorer than the other two groups 

during the Baseline nights, but its performance 

improved significantly during the Boom and Recovery nights. Overall performance was better 

in the evening than in the morning. 

Summary of Performance Results. In no way 

was there any decrement in performance which 

could be attributed to the booms. The differences 

which were obtained relatiYe to age and to timeof-day (the direction of which agree with other 

literature, e.g., Chiles et al., 1968; Ray, Martin, 

and Alluisi, 1961; Trumbull, 1966) indicate that 

the tasks were sensitive enough to detect decrements had they occurred. However, since overall sleep patterns had not been affected by the 

booms, no decrements in performance were likely. 

In fact, performance measures during Boom 

nights were better than the Baseline levels in 26 

of 30 comparisons (ten measures by three age 

groups). 

Overview 

The results of this study demonstrated no significant effect of the simulated sonic booms, presented during sleep, on overall patterns of sleep 

when Boom nights were compared with Baseline 

24 

and Recovery nights. Similarly, there were no 

deleterious effects on complex performance measures and no changes in assessed moods which 

could be attributed to the booms. 

However, presentation of the booms did evoke 

some responses in all subjects. Heart rate increased slightly during the minute following 

booms (on the average, by less than one beat for 

any age group), changes in muscle tone occurred 

for 45-50 per cent of the booms (about three 

times more often than chance changes might be 

expected based on pseudo stimulus controls) and 

basal skin resistance changed in response to 

about 19 per cent of the boom presentations. It 

is of particular interest that, for each of the 

measures noted above, the frequency of occurrence of the changes increased with the age of 

the subject-groups. 

That the boom-induced responses were functionally not significant is best attested to by the 

facts that overall sleep patterns and overall 

physiological activity (i.e., on a nightly basis) 

were not significantly affected, and that the 

booms rarely produced shifts in stage of sleep 

(about 14 per cent of the time as compared with 

4 per cent for pseudo stimulus controls) and 

even more rarely produced awakenings (about 5 

percent of the time). However infrequent, the 

occurrences both of a wakening and of stage 

shifts increased from the youngest to the oldest 

age groups. On the average, booms produced 

awakenings once or twice and shift changes about 

ten times in each of the youngest subjects for all 

Boom nights (i.e., in response to a total of 96 

booms per subject) ; the corresponding occurrences per subject in the 40-45 year olds were 

six and 13, respectively, and for each subject in 

the 60-72 year old group, eight and 18, respectively (cf., Table 10). These ag~-related differences in response to simulated sonic booms agree 

with other findings (Lukas, Dobbs, and Kryter, 

1970; Lukas and Kryter, 1968, 1970a, 1970b). 

To provide some frame of reference for evaluating the infrequent and/or short-duration responses to individual booms recorded in this 

study, a report by Thiessen ( 1970) may be useful. Thiessen used magnetic tape playbacks of 

the noise of a passing truck (levels ranged from 

40-70 dB A) and presented seven noises a night 

for 12 successive nights. Based on his results, 

awakenings or shifts in sleep level would be ex-
pected between 10-20 per cent of the time in 

response to the lowest levels ( 40--45 dB A) of 

truck noise which he used. This frequency of 

response is similar to that produced by booms 

in the present study (Table 10; Williams Scores 

5 and 7) even though the dB A level of the booms 

was higher than the levels of truck noise noted 

above. Perhaps, for a given behavioral effect, 

subjects can tolerate the higher sound level of 

very short-duration booms (at least at low overpressure levels) as well as they can tolerate lower 

sound levels of longer-duration noises. 

In the present study, awakenings were scored 

on the basis of evidence in the physiological 

tracings and were not the "behavioral a>vakenings" (whereby subjects signal their waking 

state) reported by Lukas and his co-workers 

(e.g., Lukas, 1970; Lukas and Dobbs, 1972; 

Lukas and Kryter, 1970a). That we instructed 

our subjects to ignore disturbances and attempt 

to get the best night's sleep possible might well 

account for the smaller number of responses to 

the booms reported here, as compared with other 

data (e.g., Lukas and Kryter, 1970a) obtained 

under conditions in which the subject apparently 

was made more aware of the purpose of the study 

and was asked to signal whenever he awakened. 

Another point of interest concerns what is 

usually referred to as "adaptation" in the literature on effects of noise. In agreement with 

earlier studies of noise effects on sleep ( cf., 

·williams, 1970) there was no significant reduction across Boom nights in the low-level physiological changes which occurred following boom 

presentations. Similarly, no significant changes 

in the EEG measures occurred across nights as a 

result of repeated exposure to the booms; the 

latter finding agrees >vith data reported by Lukas 

and Kryter ( 1970a, 1970b) for simulated booms, 

by Thiessen ( 1970) for truck noise, by Kramer et 

al. (1971) for the striking of a hammer, and as 

summarized by ·williams ( 1970) for other aeons25 

tic stimuli. However, it might be more appropriate to refer to such results as a failure to 

obtain "habituation" rather than "adaptation," 

considering the nature of the test situation and 

the relatively brief and infrequent presentatiqns 

of the boom (or other acoustic) stimuli. 

IV. Summary. 

Eight male subjects in each of three age groups 

(21-26, 40-45, 60-72 years) slept in pairs in the 

CAMI sonic boom simulation facility for 21 consecutive nights. The first five nights were used 

to acclimate the subjects (nights 1 and 2) and to 

obtain Baseline data (nights 3-5); the 12 subsequent nights (Boom) involved the hourly presentation of simulated sonic booms at an overpressure level of 1.0 psf (as though measured 

"outdoors") ; during four additional nights (Recmrery) there were no boom presentations. Allnight records of EEG, EOG, EMG, ECG, and 

BSR were obtained and analyzed. None of these 

physiological measures showed any statistically 

significant effect of the boom presentations on 

nightly sleep patterns. However, the individual 

booms did arouse ECG, EMG, and BSR responses in all subjects; average heart rate increased during the minute following each boom 

(by less than one beat per minute), EMG responses occurred for 45-50 per cent of the booms, 

and BSR changed following 19 per cent of boom 

presentations. The frequency of these occurrences increased as a function of age. That 

these changes were probably mild is supported 

by the facts that only 5 per cent of the booms 

produced awakening and only 14 per cent produced shifts in stages of sleep ( 4 per cent of the 

stage shifts might be expected by chance) ; both 

of these measures showed higher frequencies of 

occurrence as a function of age. The changes 

in sleep appear roughly comparable to what 

might occur in response to the noise of a passing 

truck at 40-45 dBA. 
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