The ASHA Leader - August 11, 2009 - (Page 5)

School Design with Acoustics in Mind by Marcus and Angela Adrian I n May the U.S. House passed legislation that allows federal funds to be used for acoustic improvements in schools, bringing us one step closer to quieter classrooms. ASHA also hosted a Capitol Hill briefing on “Classroom Noise and Acoustics: The Unseen Barriers to Learning” on May 15 to highlight the impact of reduced noise and good acoustics on academic performance, underscore the cost-effectiveness of improvements, and showcase quiet classrooms around the nation. Architectural design strategies for quiet classrooms and practical ideas for improving speech intelligibility in new or existing buildings were presented at the Capitol Hill briefing. strategies always begin with identifying and reducing noise before considering any amplification of signal. Some sources of noise are more detrimental to speech intelligibility than others. Prioritizing these sources in four categories helps to spend construction or renovation dollars efficiently: • Mechanical system noise from air ducts, pipes, and related machinery • Outside noise from traffic, playgrounds, and other sources outside the building • Building noise from corridors, other rooms, and other floors inside the building • Room noise generated by each classroom’s occupants Audibility Alone Is Never Enough Whether designing large classrooms or small treatment rooms, the architect’s highest acoustic priority is always speech intelligibility, and achieving this requires more than an overall increase in the audibility of the target signal or a decrease in noise. For younger learners, attention should be focused on the audibility of critical speech frequencies—those between 500 Hz and 6,000 Hz—because background noise in this range can mask the consonant and blend sounds that allow the brain to distinguish between similar-sounding words. Older learners, who have acquired more The walls of this early childhood classroom at Central Institute for the Deaf in St. Louis, Mo., have tackable sound-absorbing panels. Mechanical System Noise Mechanical noise is usually the primary noise culprit because of its volume and vast frequency range. The low-frequency rumble of big mechanical units can be reduced by placing them on base isolation pads and locating them as far as practical from classrooms. If they are mounted on the roof, they are best located over restrooms, teacher work areas, or supply and file rooms. Acoustical linings can prevent sheet metal ductwork from transmitting mid-range fan noise over long See Acoustics page 6 spoken language vocabulary, are better able to “fill in” these dropped consonants and words from context. Because one classroom’s signal is always the next classroom’s noise, the most productive design Audiology in Brief Protein Patches Up NoiseInduced Damage A new animal model study provides new insights into how noise damages the stereocilia bundles in ears and how that damage can be repaired. Researchers at the National Institute on Deafness and Other Communication Disorders found that when mice are exposed to loud sounds, gaps form in the stereocilia bundles like giant potholes on a street. If not repaired, the gaps grow, degrading the stereocilia and causing permanent hearing loss. The research team was surprised to learn that a protein, gamma-actin, helps fill the stereocilia bundle gaps caused by excessive noise levels, while a second, closely related protein, beta-actin, is responsible for building the structures in the first place. In the absence of gamma-actin, beta-actin does not efficiently repair or prevent further damage to the stereocilia. The researchers were the first to develop a mouse in which the gamma-actin gene was knocked out, rendering it unable to produce the protein. Because gamma-actin is found in all cells in the body, scientists believed that an animal without the protein would not survive. However, the research found not only did some of the genetically altered mice live, but also that their hearing was normal at 6 weeks of age, when a mouse’s hearing is fully matured. However, by 24 weeks, the mice had profound hearing loss. Visit the June 16 issue of the Proceedings of the National Academy of Sciences (Vol. 106, No. 24) at months and 61% were fit later or lost to follow-up. Factors associated with loss to followup included unilateral hearing loss, late diagnosis, conductive hearing loss, and Medicaid coverage. This article in the June 2009 issue of the American Journal of Audiology (http://aja. is offered for CEUs. their successful approaches to helping patients and families understand and appreciate the audiogram. The best submission will win a free trip to an institute seminar in Denmark. To enter, submit a script or description of the approach (not to exceed two typed pages), to The Ida Institute, an independent, educational non-profit near Copenhagen, is funded by a grant from the Oticon Foundation. For more information, search “contest” at www. Newborn Hearing Screening Loss to Follow-up Are newborns screened for hearing being fit with hearing aids by 6 months? Researchers at the Long Island Jewish Medical Center in New York examined the screening and follow-up records of 114, 121 infants over a six-year period. They found that 91% of referred infants returned for follow-up evaluation. Hearing aids were fit on 107 of the 192 infants. Of these, 39% were fit by age 6 Good at Explaining Audiograms? The audiogram: Is it objective data that helps people understand their hearing loss or a bewildering See other audiology-related stories on pages 3, series of lines and 7, 8, 10–13, 14–17, 19, 41, 44, 46, 47, and 50. circles? The Ida If you’d like to submit an article idea or provide Institute invites feedback on this audiology page, send an e-mail hearing care profesto sionals to share August 11, 2009

Table of Contents for the Digital Edition of The ASHA Leader - August 11, 2009

The ASHA Leader - August 11, 2009
Four Members Elected to Board of Directors
Readers Respond
Congress Begins Health Care Reform Debate
Medicare Private Practice Poses Concerns for Some SLPs
Custom Fit Your Marketing
Personal Music Players
From the President
Convention Preview
2010 Dues Change
Ethics in Private Practice
Missouri SLPs Win on School Retirement Issue
A Deluge of Human Kindness
First Person on the Last Page

The ASHA Leader - August 11, 2009