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Researching Cost Effectiveness



Finances are a reality and more often than not determine which initiatives will be implemented. They are especially relevant in school districts and political venues where budgets are scrutinized for programs considered essential. While those who have educated themselves on the benefits of sound enhancement understand the NEED for improving the auditory learning environment to ensure fairness to ALL children in the classroom, others ignorant of the topic may look at this technology as a “luxury item”. Therefore, when opportunities are limited to fully educate those making the educational decisions; it is helpful to emphasize the financial as well as the social and moral return on this investment.

Sound enhancement systems cost on average $1500 per classroom. However, the cost may be offset in financial savings resulting from declines in teacher absenteeism and declines in special education referrals. These savings alone may be significant enough to completely recover the initial cost in two to five years. This may be why sound enhancement was named number four out of the top ten “Returns on Investment” by Technology and Learning (Nov. 2004) magazine. Read the article here

Most school district officials and administrators will not argue the benefits of a sound enhancement system; particularly in light of compliance with the standards under the No Child Left Behind Act, a desire to increase literacy, and a national movement to recognize the importance of acoustics in learning. But, the overwhelming response to any new initiative is how much does it cost? And when a single classroom cost is multiplied over an entire school district, the financial considerations seem to dominate the discussion overshadowing the need and benefits for implementation.

The cost of a classroom sound enhancement system varies greatly depending on the manufacturer, the specific product, number of speakers throughout the classroom, extra options (such as the ability to plug into any media source within the room), installation considerations, portability, etc. The average range varies from $1300 to $1700; therefore, for purposes of discussion let’s assume a cost of $1500 for a four speaker system installed in a classroom with 25 students. That would equate to $.33 per student per day or $.07 per day when allocated over a life of five years. When compared to the cost of other instructional equipment used on average less hours per day, a sound enhancement system is equal if not less expensive than a television monitor, computer and printer, LCD projector; all of which have not been researched to prove such a positive impact on student performance.

Use of sound enhancement systems have significant financial benefits as well, enough in some cases to completely recover the purchase and installation cost within two and a half to five years. The most significant benefit (financially) is derived from the potential to reduce the number of children identified and referred to Special Education programs.

Special Education Reductions

According to a Special Education Expenditure Project (SEEP) report issued by the American Institutes for Research, during the 1999-2000 school year, the 50 states and the District of Columbia spent approximately $50 billion on special education services, amounting to $8,080 per special education student. The total spending to provide a combination of regular and special education services to students with disabilities amounted to $77.3 billion, or an average of $12,474 per student. An additional one billion dollars was expended on students with disabilities for other special needs programs such as Title I, English language learners, or gifted and talented students, bringing the per student amount to $12,639. Based on these figures, the total expenditure to educate the average student with disabilities is an estimated 1.90 times that expended to educate the typical regular education student with no special needs. Excluding expenditures on school facilities, the ratio of current operating expenditures on the typical special education student is 2.08 times that expended on the typical regular education student with no special needs.i

The financial cost to society to “label” a child as needing Special Education services are staggering, not to mention the cost to the students themselves for enduring the stigma of identification with a group of children “unlike the others” in mainstream education. Therefore, reducing the number of children ear-marked for a Special Education program provides a significant social and financial return of investment. Sound enhancement systems have been proven to do just that.

From 1985 to 1990, the Putnam County School District in Ohio (Phonic Ear, 1994) phased in 60 sound enhancement units to help children with learning disabilities attend to verbal instruction in the mainstream classroom. The cost of the equipment at $1,500 per unit totaled $90,000. However, over the 5 year period, the number of students placed in learning disabilities programs declined nearly 40%, a reduction of 26 students, at a savings of $2,600 per student. Therefore, the total savings in reduced learning disabled referrals was $67,600. Projecting that decline forward an additional 5 years (realistically because ALL the systems were then in place) would result in a total savings of $338,000, more than 3.7 times the cost of the sound enhancement equipment.

Declines in Special Education referrals have been reported in other research studies as well. Long and Flexer (2001) reported that special education referrals declined by nearly 50% after 37 elementary classrooms, kindergarten through fifth grade, received sound enhancement systems and used them for an eight month period.

The MARRS project that took place in the Wabash and Ohio Valley schools in southern Illinois (1977-1980) found that not only did students show significant gains in academic achievement, but they also were noted to achieve in reading and language arts at a faster rate, to a higher level, and at one-tenth the cost of students taken from regular classes and provided instruction in a resource room setting.ii The academic gains were effectively realized within the regular classroom without the need for stigmatizing labeling and segregations as well as expensive scheduling complications of special class placement.” iii

Over a three year period, the Ohio Office of Education conducted a study referred to as MARCS, Mainstream Amplification Regular Classroom Study (Flexer, 1989, 1992; Osborn, VonderEmbse, & Graves, 1989). This investigation took place in 9 rural school districts in Ohio, to measure the cost-effectiveness and efficiency of using sound enhancement systems. The results indicated that fewer special education referrals and learning disability placements took place in schools with the greatest number of sound enhancement systems in the lower elementary grades. iv

While reductions in special education referrals are more likely to be attributed to schools with higher levels of learning disabled students, savings from reduced teacher absenteeism are universal.

Reduced Teacher Absences

As discussed under Teacher Preferences, sound enhancement benefits teachers include a reduction in vocal strain and fatigue. This ultimately reduces the number of teacher absences and the need and expense for substitute teachers. Several studies have confirmed this reduction. One such study (Allen,1995) reported a 56% decline in absences of elementary teachers from vocal fatigue.

The study previously referred to in Dubuque, Iowa confirms this theory. Teachers in sound enhanced classrooms took on average .34 days per year per teacher for a vocal related illness, compared to those NOT in sound enhanced classrooms that averaged .97 sick days per year for a vocal malady (Allen 1995). v

In Milwaukee, audiologists Doug Kloss and Joanne Colombo-Hughes launched a pilot study during the 2002-2003 academic year. Four classrooms from kindergarten to third grade were amplified and compared to four control classrooms. The year before sound enhancement systems were in place, the same teachers had a combined 35 absences, compared to only five during the study year; a staggering 85% reduction in teacher absenteeism. vi(It should be noted that the reason for the absences was not noted. Therefore, we cannot attribute the entire reduction to decrease in vocal fatigue or vocal related problems.)

While these cost savings are significant and note-worthy, some individuals will advocate facility building modifications as opposed to sound enhancement systems to improve the auditory learning environment.

Less Expense than Acoustical Modifications

There will always be school districts that claim to recognize the importance of acoustics in learning, but opt to refer to the ANSI S12.60-2002 standards as a means to improve the learning environment. As discussed under Acoustical Modifications, the ANSI standards emphasize the importance of good acoustics and provide a worthwhile baseline for establishing acoustical standards. But in addition to falling short of providing an effective means to ensuring that ALL children have a signal to noise ratio of +15 dBA, implementation of the recommended building materials and improvements to achieve the desired level of background noise and reverberation are very costly. So much so, that in 2002, the International Code Council rejected the inclusion of the ANSI standards into the 2003 International Building Code.

In 2003, the U.S. Access Board estimated that school systems currently in the top quartile for construction spending would incur an average .5% increase to meet the Standard with an average cost of 3% for schools at the spending median. Low-quartile systems still using through-the-wall fan coil units might see as much as 5-7% increases in construction costs.

Renovations of existing older school buildings may be even more costly and less effective. Overcoming intrusive exterior and interior ambient noise or HVAC noise is more difficult and costly. Expenses may include the cost of a new HVAC system, redoing the duct work, installing acoustical tile, replacing existing windows with a sound insulating type, etc.

One parent, Melanie Doyle, petitioned her school district to make the necessary acoustical modifications to her son’s public elementary school in San Diego. Her son, Crosby, has a severe to profound hearing loss. Melanie fought to have the ANSI specifications regarding background noise and reverberation written into her son’s IEP. “The overall cost to the district for all the modifications at Curie Elementary came to $22,000 with Owens Corning donating $10,000 in the form of testing, supervision and product.” vii This amount represents acoustical modifications made JUST to her son’s classroom, school auditorium, and speech therapy room. Sound enhancement systems at a maximum cost of $1800 each would have cost a total of $5,400 for the equivalent space.

Another cost comparison needs to be made in regards to relocatable or portable classrooms. These types of classrooms are becoming increasingly common to accommodate growing populations of children in school districts, without incurring the significant expense to renovate the existing building. Not surprisingly, sound level measurements in traditionally constructed relocatable classrooms exceed recommended acoustical standards. Sound enhancement systems can be installed in portable classrooms to achieve a positive listening environment for approximately one-fourth the cost of construction modifications. viii

It is important to recognize the elements and materials that support good acoustics, and to every extent possible, make the cost-effective improvements that can help contribute to good acoustics. But the cost and benefits of installing sound enhancement systems, significantly outweigh those of implementing the ANSI standards by themselves.

Summary table of sound enhancement efficacy studies demonstrating cost-effectiveness

Table data taken directly from Sound Field Amplification: Applications to Speech Perception and Classroom Acoustics (Second Edition) by Carl C. Crandell, Joseph J. Smaldino, and Carol Flexer.

Investigators Student Population Cost-Effectiveness of SES*'s
Sarff (1981); Ray, Sarff, and Glassford (1984) MARRS project (fourth-through sixth-grade students with minimal hearing loss, academic deficit, and normal learning potential The MARRS project demonstrated that students with minimal hearing loss and learning disabilities in amplified classrooms made significant academic gains at a faster rate, to a higher level, and at one-tenth the cost of students in unamplified resource-room settings.
Rosenberg (1998) One acoustically modified and one amplified relocatable classroom SES* was provided at one-fourth the cost of acoustical modifications in newly constructed relocatable classrooms.
Rosenberg et al. (1999) 54 general education K-2 amplified classrooms Typical classroom (25 students, one teacher) daily cost per person was $.14 or $.03 per day over five years.


* SES = Sound Enhancement System


  1. American Institutes for Research, Special Education Expenditure Project “What Are We Spending on Special Education Services in the United States, 1999-2000?”. Updated June 2004.
  2. The MARRS PROJECT: Mainstream Amplifaction Resource Room Study
  3. The MARRS PROJECT: Mainstream Amplifaction Resource Room Study
  4. Crandell, Carl C., Joseph Smaldino, and Carol Flexer. Sound Field Amplification: Applications to Speech Perception and Classroom Acoustics. (page 80) Canada: Thomson Delmar Learning, 2005.
  5. Crandell, Carl C., Joseph Smaldino, and Carol Flexer. Sound Field Amplification: Applications to Speech Perception and Classroom Acoustics. (page 103) Canada: Thomson Delmar Learning, 2005.
  6. Boswell, S. (2006, May23). Sound field systems on the rise in schools: Improved test scores cited as benefit. The ASHA Leader, 11(7), 1, 32-33.
  8. Educational Audiology Association, “Relocatable Classrooms: Acoustical Modifications or FM Sound field Classroom Amplification” pp. 9-13 Gail Gegg Rosenberg