Phase I – As a consultant to Freytag & Associates, we performed an airplane noise assessment for the District of Columbia focused on noise impacts from changes to flight paths made out Ronald Reagan Washington National Airport (DCA). There were two major parts to the project. The first consisted of a thorough review and documentation of existing data supplemented by new investigations to document the past and current airplane noise environment over the D.C. area. Second, the team worked to develop revised air traffic procedures, acceptable to the FAA, to minimize the current noise impact over the affected areas in D.C. The overall purpose of the project was to determine what, if any, noise impacts have occurred in the District as a result of the FAA’s implementation of NextGen air traffic control procedures and routes. Finally, we identified potential flight path/route changes and other airspace modifications to reduce flyover noise in the District.

Phase II – This phase built on the previous Phase I study. Utilizing the measurement data collected in Phase I, the consultant team computed various supplemental noise metrics (Lmax, Leq, Time Above Level, etc.) to further quantify noise impacts and changes in aircraft noise due to arrivals and departures at Ronald Reagan Washington National Airport (DCA). Additional long-term field measurements were conducted and the consultant team quantified the community impacts (e.g., sleep disturbance, speech interference) according to national standards. Additionally, we identified and encouraged improvements and changes to existing noise abatement procedures and practices to reduce aircraft noise impact over the District. Specific noise mitigation recommendations were developed for presentation to airport management, the Metropolitan Washington Airport Authority (MWAA), and to the Federal Aviation Administration (FAA). The primary beneficiary of this project is the District residents, as the goal of the project is to reduce DCA aircraft noise impacts and improve residents’ quality of life through aircraft noise reduction.


LOCATION: Inglewood, CA
PROJECT TYPE: Residential Sound Insulation
CLIENT: City of Inglewood
PROJECT COST: $37.9 million (Construction)

In 2013 CSDA was contracted with the City of Inglewood to provide architectural and engineering design services for the Residential Sound Insulation Program (RSIP). To date, CSDA has surveyed and designed modifications for 949 individual residences. The RSIP, which was funded by the Federal Aviation Administration (FAA) and Los Angeles World Airports (LAWA), consists of the following scope of work:

  • Conduct architectural surveys
  • Prepare sound insulation modification plans for each unit to be insulated
  • Complete pre- and post-construction acoustic testing for a portion of the homes
  • Compile hazardous materials surveys and reports
  • Prepare construction cost estimates
  • Prepare bid documents (drawings, details, and specifications)

In addition to the above, CSDA is providing construction administration support, including field observation, punch lists, and contractor coordination.

CSDA was also retained to provide Program Management in support of the City’s facilitation of the overall RSIP and other Program consultants. Our services include assistance with grant reporting, parcel tracking database creation and management, and recommendations to streamline and improve the efficiency of the Program. CSDA provided full-time support to the City, working alongside City staff, to help the City achieve their goal of sound insulating over 1,000 residences per year in 2014 and 2015. CSDA also liaised with LAWA staff during the preparation of related grant reporting documents and other program documents.




Los Angeles Sound Insulation Program – Creating Quieter Neighborhoods.

The City of Inglewood Residential Sound Insulation Program was highlighted in in the August/Sept 2015 Airport Magazine. Read the article Los Angeles Sound Insulation Program – Creating Quieter Neighborhoods.




Inglewood Milestone_thumbnail

Inglewood Celebrates Sound Insulation Milestone

On December 8, 2015, representatives from CSDA Design Group,  City of Inglewood and Los Angeles World Airports (LAWA) toured the 2,000th home to receive sound insulation in 2015. Read the full story in the Los Angeles WAVE.





As part of the settlement agreement between Los Angeles International Airport (LAX) and Lennox School District, LAX is providing funding to sound mitigate one pre-school, five elementary schools, one middle school, and three high schools impacted by aircraft noise. CSDA was contracted to provide design solutions for one middle school and two elementary schools.

CSDA provided the acoustical testing, architectural design and construction administration services to acoustically treat Lennox Middle School, Jefferson Elementary School and Buford Elementary School to reduce interior noise levels to meet the 45dB standard. The Lennox Middle School project encompasses seven buildings including 45 classrooms (43,237sf) and a gymnasium (9,011sf). The Jefferson Elementary School project includes three buildings, including 25 classrooms (15,028sf). The Buford Elementary School includes 30 classrooms, two staff prep rooms, two offices, and one library (31,100sf).

Acoustical remedies are being made to the exterior and interior of the buildings. Exterior remedies include treating the exterior walls with sound insulation and installing sound abatement devices on rooftop HVAC units. Interior modifications to classrooms include the installation of sound proof windows and doors. Interior modifications to classrooms include the installation of new sound absorbent ceiling tiles and panels. Since construction is occurring while the school is in session, six temporary classrooms have been set up to allow phased construction of six classrooms simultaneously.


CSDA was selected for the Airport Cooperative Research Program (ACRP) study 02-51 to evaluate methods for determining interior noise levels used in airport sound insulation programs nationwide. Our team of expert researchers is evaluating acoustical measurement methods employed in FAA-sponsored airport sound insulation programs, including: aircraft flyover, elevated exterior loudspeaker, ground level exterior loudspeaker, indoor loudspeaker and sound intensity.

The objectives of this research are to: (1) identify and evaluate the accuracy of noise level reduction (NLR) measurement methods; (2) propose procedures to minimize the measurement inaccuracies of each method; and (3) develop a matrix to help program sponsors identify the most appropriate methodology for determining interior noise levels for their airport sound insulation program.

CSDA is working with the following consultants on this study:

  • Dr. Paul Schomer, PE – Schomer and Associates
  • John Freytag, PE – Freytag & Associates, LLC
  • Herbert Singleton, PE – Cross-Spectrum Acoustics LLC



Impacted by aircraft noise from nearby San Francisco International Airport, acoustical treatments were made to more than 6,600 single- and multi-family homes, three churches, one school and a convent to reduce interior noise levels. Program management, design, community outreach and construction administration services were provided. Instrumental to the program’s success was the development and implementation of a Community Outreach Program and Showcase Home to stimulate homeowner participation in the program. Completed in accordance with a client-driven accelerated schedule, approximately 1,400 homes were acoustically treated each year over a three-year period.