Robert M. Hoover

A Double Wall Noise Control Enclosure for an Impulsive Sound Source

The design of a group of double wall noise control enclosures on the upper floor of an existing building is described and some noise reduction measurements are reported. A design objective for these enclosures was to achieve more effective noise reduction than that provided by existing heavy, on grade, double wall, reverberant enclosures, but with reduced weight. This objective was achieved by a combination of a lightweight inner skin, a moderately large air space, a masonry exterior, isolation of the inner room floor slab, and the use of sound absorbing materials. Other noise control measures included sound retarding doors and windows, mufflers in the air supply and return passages, and flexible service connections to the rooms. Peak and octave band noise levels taken inside and outside the old and new enclosures are reported.

Acoustic Filter for Water‐Filled Pipes

It is anticipated that some of the auxiliary equipment to be used in conjunction with the new water tunnel under construction at the Pennsylvania State College will be particularly noisy in the ultrasonic frequency region where certain low level acoustic measurements are to be made. This potentially noisy equipment includes such items as a deaerator, an energy dissipator, and a pressure control system which are located in a water loop, external to the main tunnel section. To effectively isolate this loop acoustically from the remainder of the tunnel where the acoustic measurements will be made, it has been considered desirable to design an acoustic filter which can be inserted at the junctions of the loop with the tunnel. This filter should serve the multiple function of reducing the sound transmission through the pipe walls and through the water in the pipes while permitting the passage of relatively large volumes of water at small loss of pressure. The problem of isolation in the pipe path is a fairly c...

Working with Cyril M. Harris at Benaroya Hall

To contribute to a project such as Benaroya Hall, now the home of the Seattle Symphony Orchestra, as team members of acoustical giant Cyril M. Harris was a golden opportunity for Robert M. Hoover and Ashton Taylor. Their involvement in the project and association with Cyril began at the early stages of the project as consultants in noise control. During the schematic design phase, Cyril dictated to the LMN Architects design team that authority for all noise control decisions rested with Bob Hoover. This led to good working relationships, especially with the mechanical engineering firm and the air‐conditioning contractor. Throughout the project, Cyril insisted upon the highest standards of materials and workmanship, and relied on the expertise of his acoustical design team, even if it went against his initial idea on some issue. At the beginning with the setting of noise criteria and in the finished building when measuring background sound, Cyril participated in the noise control process. Benaroya Hall has been critically acclaimed by the media and musicians, it was an honor for both Bob Hoover and Ashton Taylor to be part of that success.

Progress report and discussion on the continuing activity on ASA’s role in noise and its control

A discussion meeting is being sponsored by the Technical Committee on Noise to review progress made to date on the actions initiated by the Technical Committee on Noise at the Denver 1993 meeting to increase the role of the ASA in noise and its control. Members of the steering committee will each review the specific activities undertaken in the areas of education, collaboration with other societies, increasing public awareness of noise and the establishment of a task force to determine feasibility of establishing an ASA clearinghouse on noise.

Increasing the Acoustical Society’s role in noise control and noise effects

At the meeting of the Technical Committee on Noise at the fall 1991 meeting of ASA in Houston, a discussion was held on how, or if, the Acoustical Society should develop more concrete policies or action concerning noise control and noise effects. As a result of that discussion, a Noise Task Group was formed by the authors at the direction of the Chair of the Technical Committee to explore the issues involved. Since that time, several special sessions have been held to help establish a direction for this activity. This talk will briefly review some of the more important elements of that activity which, properly, are beginning to involve members of other technical committees within the Society in such areas as hearing screening tests at ASA meetings, development of lecture materials for use in presenting talks to youth on acoustics and noise, and potential development of room noise criteria and/or rating schemes for meeting spaces. Other such action areas that have evolved from these special sessions will b...

Progress report on the continuing activity on the ASA’s role in noise and its control

A discussion meeting is being sponsored by the Technical Committee on Noise to review progress made to date on the actions initiated by the Technical Committee on Noise at the Denver 1993 meeting to increase the role of the ASA in noise and its control. Members of the steering committee will each review the specific activities undertaken in the areas of education, collaboration with other societies, increasing public awareness of noise, and the establishment of a task force to determine feasibility of establishing an ASA clearinghouse on noise.

Final group presentation

This final plenary session of the Workshop will include presentation by the moderators/recorders of all the working groups on their findings. The final set of recommendations will be presented to the meeting of the Technical Committee on Noise, to be held on Thursday evening, 20 May 1993

Progress report on the continuing activity based on the May 1993 special workshop on the ASA’s role in noise and its control

A discussion meeting is being sponsored by the Technical Committee on Noise to present the progress that has been made to date on the recommended actions that were developed by the working group participants of the May 1993 Special Workshop on the ASA’s role in noise and its control. The results of the May workshop will be summarized. Representatives of each working group will present a discussion of the progress on specific initiatives that have been begun. These will include any collaborative actions being taken with the cooperation of other Technical and ASA Standing Committees.

Case histories in licensing an industrial facility

In recent years, there has been a proliferation in the siting of small to moderate sized power‐generating facilities in noise‐sensitive communities. Some of these communities have little or no experience with industrial facilities and some have adverse experience. In many cases, this has led to noise‐control requirements in the form of ordinances or licensing requirements that are overly strict. In addition, many of the personnel involved in the early development of plant budgeting, contracting, and conceptual design have little experience with technology for evaluating or controlling sound. Consequently, this has often led to inadequate attention to noise control requirements in the early stages of plant contracting and design. Several examples of noise‐control problems frequently encountered in the licensing of these power generating facilities are described.

Performance of several mufflers for induced draft fans

Community noise problems due to the operation of induced draft fans were investigated at several installations. Custom designed mufflers have been installed, evaluated, and found to be satisfactory. Special features include significant attenuation of tonal noise at frequencies of less than 500 Hz and the ability to operate in contaminated gas streams.