Ecophon Acoustic Bulletin

A recent study called "Noise exposure in a neonatogical care unit and in incubators" demonstrated a far from ideal environment for neonatals inside incubators.

Summary
The noise exposure of premature infants in incubators is determined by the noise situation in the neonatological care unit and on the other hand by acoustical properties of the incubator, which should shield the premature infant against an excess of noise beside the primary life-saving functions. The noise inside a neonatological care unit is caused by lot of supplying and controlling devices provided with loud alarm functions, but also by the nursing staff and visitors.

The report can be ordered here

The high production of noise is promoted by the normally high density of the incubators in the unit. The noise exposure in the unit and the acoustical properties of the incubators are investigated with the result, that the LAeq of the quietest hour within 24 hours was 49 dB(A) still. This and other results are showing, where necessary steps should or have to be taken, what is fortunately realized parts at least. in

Posted by Marc Janssen at 11:41 AM | Permalink

The new HTM (Health Technical Memorandum) gives Design Criteria for Room Acoustics in UK Healthcare Premises.
The document's Executive Summary states "Noise can increase heart rate, blood pressure, respiration rate and even blood cholesterol levels. Good acoustic conditions improve patient privacy and dignity, and promote essential sleep patterns. Such conditions are key to healing"
Recently published, it requires acoustic treatment, usually ceilings, to be provided in all occupied areas, including corridors.
"The requirement is ...

for a minimum area of absorption equivalent to Class C absorber covering an area of at least 80% of the floor area. The ceiling should also be washable in areas within the Infection Control regime."
Using a superior Class A absorbing ceiling will provide a number of additional acoustic benefits to patients and staff - rooms will be less reverberant, overall sound levels will be lowered, speech will sound clearer, and intrusive noise from nearby areas will be reduced.

HTM 08.01 is available from www.tsoshop.co.uk

Listen to an interview with Adrian Popplewell (Arup Acoustics) as he comments on his involvement in drafting the HTM 08.01.

By Anthony Thomas,
Concept Developer, Healthcare - UK and Ireland

Posted by Anthony Thomas at 3:37 PM | Permalink

The Audio Spotlight is a revolutionary new audio technology developed by dr. Joseph Pompei, that creates sound in a narrow beam, just like light. Aim the flat, thin speaker disc to your desired listening area, and provide all of the sound — with none of the noise. Image the possibilities!

Technology

History

The technique of using a nonlinear interaction of high-frequency waves to generate low-frequency waves was originally pioneered by researchers developing underwater sonar techniques dating back to the 1960's 1. These early acoustics researchers successfully derived the formal mathematical basis for this effect and developed innovative sonar systems with more directivity and bandwidth than would otherwise be available. They called this device a parametric array.

In 1975, the first publication 2 appeared which demonstrated that these nonlinear effects indeed occur in air. While these researchers had not attempted to reproduce audio, they nonetheless proved that such a device may be possible.

Over the next two decades, several large companies, including Matsushita (Panasonic), NC Denon, and Ricoh attempted to develop a loudspeaker based on this principle, and published a paper describing one attempt in 1983 3. While they were successful in producing some sort of sound, problems with cost, feasibility, and extremely high levels of distortion (>50% THD) caused the almost total abandonment of the technology by the end of the 1980's.

While a graduate student developing '3D Audio' at Northwestern University in the late 1990's, Joseph Pompei had similar ideas of using ultrasound as a loudspeaker, largely to overcome deficiencies he saw with traditional methods of sound reproduction. After performing extensive research on the idea, he discovered the large body of knowledge in the field of nonlinear acoustics, as well as the earlier attempts at using ultrasound as an audible source. Soon after arriving at MIT, his insight led him to identify – and subsequently rectify – the barriers which had plagued the earlier researchers.Through a combination of careful mathematical analysis and solid engineering, he was able to construct the very first, and still only, practical, high-performance audio beam system 4.

Read more on: www.holosonics.com