Ecophon Acoustic Bulletin

Posted by Anthony Thomas at 12:50 PM | Permalink

In "Challenging Designs of Neonatal Intensive Care Units", Anne Marie Dazé Floyd, RN, MSN, CNS says:
A link has been established between exposure to constant room noise and loss in frequency and pattern discrimination essential to understanding the spoken word. Loss of an ability to discriminate speech can cause profound developmental delay by interfering with language acquisition.
In addition to the connection between noise levels and deficits in hearing discrimination, clear connections also exist between noise and physiological instability.

Unlike light, noise is a normal aspect of fetal development. Fetuses normally mature in utero accompanied by a variety of noises generated by the maternal viscera and voice. These uterine noises are rhythmic and familiar and are generally low frequency, at a mean of 50 dB. In the past, noise levels inside isolettes have been measured in excess of 90 dB, the level at which the Occupational Safety and Health Administration requires ear protection in adults to prevent hearing loss. Newer models of isolettes now meet the recommended standard that motor noises not exceed 50 dB. However, infants in isolettes can still be exposed to high levels of noise. Something as simple as abruptly closing a solid plastic porthole can generate in excess of 100 dB inside an isolette.
Although normal NICU room noise, which averages less than 70 dB, has not been proved to cause classic hearing loss, a link has been established between exposure to constant room noise and loss in frequency and pattern discrimination essential to understanding the spoken word. Loss of an ability to discriminate speech can cause profound developmental delay in survivors with no other disabilities by interfering with language acquisition.
In addition to the connection between noise levels and deficits in hearing discrimination, clear connections also exist between noise and physiological instability. Preterm infants can experience repeated apneic episodes and clinically important reductions in oxygen saturation and bradycardia when exposed to normal adult activities in a NICU. Limiting neonates’ exposure to adult activities can decrease the number of alarms that represent physiological decompensation. One result of private and semi-private rooms is that fewer adults are in the room and a natural decrease occurs in the noise generated by activity and conversation. In a study by Robertson et al, decreasing conversation had the greatest effect on decreasing noise levels in the NICU.

Anne Marie Dazé Floyd is the clinical administrator for the Replacement Hospital Project
at Childrens Hospital Los Angeles, Los Angeles, Calif. She has more than 15 years of experience
in nursing administration on both coasts in pediatric, neonatal, and pediatric
intensive care units. She is the coauthor of Code Pink: A System of Neonatal-Perinatal
Resuscitation and Neonatal Nursing.

Posted by Anthony Thomas at 11:39 AM | Permalink

Nurse researchers have provided evidence that hospital critical care unit (CCU) noise may put patients at risk of sleep problems. The study, by M Topf and M Bookman at University of Colorado Health Sciences Center, goes on to say that technological advances in CCU's are contributing to this problem and that the results provide support for the hypothesis that CCU sound levels impact negatively on subjective sleep.

Although data on the negative effects of CCU noise on physiological sleep are available, less attention has been given to self-reports of the subjective quality of sleep following exposure to this stressor. This study hypothesized that subjects exposed to CCU sound levels would report poorer subjective sleep than subjects in a quieter environment. Sixty female subjects, attempting to sleep overnight in a laboratory, were randomly assigned to an experimental group, where they heard an audiotape recording of CCU sounds throughout the night, or to a quiet group where the audiotape recording of CCU sounds was withheld. A self-rating questionnaire was used to assess subjective sleep. The noise condition subjects reported taking longer to fall asleep, less time sleeping, more awakenings, poorer quality of sleep compared to home, as well as fewer positive and more negative adjectives descriptive of sleep. Self-reports of the time spent sleeping and the number of negative adjectives descriptive of sleep yielded the greatest number of significant correlations with scores for the other measures of sleep, indicating that these measures may be more accurate. Data on the quality of dreams yielded no difference between groups. The results provide support for the hypothesis that CCU sound levels impact negatively on subjective sleep. It was recommended, now that CCU sound levels were isolated in the laboratory as a potential stressor, that future research should attempt to replicate this study in a hospital CCU.

Posted by Anthony Thomas at 11:20 AM | Permalink

Birmingham Women's Hospital NHS Trust took part in a regional campaign to raise awareness of noise levels in Neonatal Units and the need to reduce them. Lead by Advanced Neonatal Nurse Practitioner Cheryl Lewis, the campaign highlighted the impact noise can have on babies, and included staff training, posters and badges, and the use of a Decibel Monitor in the Unit.

Neonatal Units can be very noisy places, with the amount of medical equipment, alarms, telephones and people's voices, and this can impact upon the babies' development.

Most of the babies are premature and should be in the womb. They are not able to shut out noise and this can be stressful, making it difficult for them to sleep.

When babies are able to have a good quality sleep they are more stable and will actually grow more quickly. In a noisy and busy environment premature and sick babies are more physically unstable, sleep less, grow more slowly and may have longer term developmental problems such as poor concentration.

Quiet time for the babies is important, and noise levels can be stressful for staff and patients too.

Posted by Anthony Thomas at 2:16 PM | Permalink

ANSWER: At least, adding absorption to a room will help to prevent tinnitus.
Scientists from the California Ear Institute in San Ramon, California have discovered a potential cure for some instances of tinnitus in the nerve agent Botox. One in four tinnitus patients in a study experienced improvement in their symptoms following treatment with Botox, 16 reported no change and three said their tinnitus had become worse.

Of course preventing Tinnitus should be priority number one. Applying stricter acoustic demands will benefit the ones suffering from Tinnitus and will support to prevent tinnitus. Effiicient absorbing ceiling panels and wall panels will support the decrease of sound pressure levels.

Read more about the tests

Posted by Per Larsen at 1:04 PM | Permalink

From March to June this year, huge screening on 7-years old children’s hearing was done in 7 eastern provinces of Poland (with 42,3 % of total country population). During 4 months, 85% of seven years old children on this territory were examined. The results point out that 20% of them have different forms of permanent or temporary hearing impairment. Big scale of this problem indicate that more strict classroom acoustic demands, used to determine environment for hearing impaired persons, should be applied commonly to all types of schools.

Program was conducted by Institute of Hearing Physiology and Pathology in Warsaw (IFiPS) with help of Hearing Impaired and Deaf Persons’ Friends Association and Board of Hearing Pathophysiology, Speech and Communication Disorders of Polish Academy of Sciences.
The main goals of the screening program were:
- detection of different forms of hearing impairment: conductive, sensorineural and central
processing disorders,
- spreading out knowledge about hearing protection, hearing impairment, possible therapy and
rehabilitation,
- improving accessibility for hearing examination for total population.

Tests were done using mobile multimedia hearing and speech screening system constructed in cooperation with specialist from Multimedia Systems Dept. in Gdańsk University of Technology. Average test of single pupil lasted 9 minutes and consisted of: checking hearing threshold in range of 250-8000 Hz, checking brain ability to process heard sounds and recording of examined individual’s speech. Individual results were immediately send to project coordinator’s server in IFiPS.

Trained volunteers visited 5701 primary schools (88,4% of this type school in the region) and examined 80.592 seven years old children (84,3% of total 7 years old children in area). Additionally, 12.284 older (8-12 years) pupils were also examined.
During whole test program following examinations were done:
- audiograms 92.876
- audiology questionnaires: 68.433
- central hearing test: 44.731
- word tests 31.161
- speech recordings 56.248

Test results showed following prevalence of hearing disorders.
Peripheral hearing disorders (conductive and sensorineural) 13,7%
Central processing disorders 15,1%
Both above malfunctions 19,4%
Hearing loss >30dB in whole range of frequencies 0,7%
Hearing loss >30dB in high frequencies (over 4 kHz) 1,1 %
In the group of 7710 children with the most serious hearing impairment, 60% of parents didn’t spot any problem.
According to data from questionnaires 33% of children have permanent or temporary tinnitius.
In the group of 10.087 children it was possible to compare actual hearing test results with other ones done just after their birth. The hearing impairment prevalence ratio grew from 0,26 % to 14,4%.
Why within first seven years of life prevalence of hearing disorders is growing 55 times? That is mostly an influence of environment. Authors of the program are naming causes:
- native disorders that come out during child growth
- conductive disorders as temporary effect of upper airways infections (in this age it can be 30%
of cases – that factor is decreasing with age)
- a third tonsil
- bony face injuries
- noise (growing factor – due to noisy environment, “noisy culture”, using earphones)
- drugs (mostly antibiotics) side effect (decreasing factor – due to growing conscience)

IFiPS started also another screening program: hearing test of whole population of 12 years old pupils in Warsaw. Similar action will be repeated in 2009 and 2010 to check possible change drift. First result are pointing out that hearing impairment ratio is similar like among 7 years old, but the reasons differs. Number of cases caused by upper airways infections decreased while number of malfunction caused by noise increased.

Posted by Mikołaj Jarosz at 11:04 PM | Permalink