"Good Neighbors Keep Their Noise To Themselves"

Buy Quiet	PRODUCT INFORMATION SUPPLEMENT No.5 PRODUCT NOISE INFORMATION SERIES JUNE, 1980
INFORMATION ON NOISE LEVELS, NOISE MEASUREMENT METHODS AND "BUY QUIET" EXPERIENCES ASSOCIATED WITH MOTORCYCLES
AN INFORMATION SUPPLEMENT FOR GOVERNMENTAL PURCHASING AGENTS IN DEVELOPING "BUY QUIET" PROGRAMS
THE NATIONAL INSTITUTE OF GOVERNMENTAL PURCHASING 1001 CONNECTICUT AVE. N.W. WASHINGTON, D.C. 20036

This packet contains information for the use of government purchasing officers and other officials in purchasing quieter Motorcycles. It is a companion document to the Guide to Purchasing Quieter Products and Services¹ which describes in general terms how noise considerations can be incorporated into purchasing decisions. Together, these documents and others available through the Quiet Product Data Bank maintained by the National Institute of Governmental Purchasing (NIGP) can help you develop a "Buy Quiet" Program for your government.

1. Issued by NIGP, May 1980.

The "Buy Quiet" Program is a new concept in which governments cooperate with each other to buy quiet models of equipment. It is being extended with the help of the National Institute of Governmental purchasing, the National League of Cities, other national organizations and various local and state agencies. This type of local noise control:

• costs very little
• requires little additional effort;
• begins the community quieting process;
• establishes market pressures

Surveys have shown that noise is the most frequently identified undesirable neighborhood condition in urban areas. Scientists and the medical profession now tell us that noise is no longer a mere irritant, but that in fact it has a very adverse impact on our health and well being. You as a purchasing officer can reduce noise in your community by purchasing quieter products. State and local governments and large private organizations spend billions of dollars each year on equipment such as compactors, chain saws, typewriters, lawnmowers, trucks, motorcycles, pneumatic drills, and buses. If these governments can become more selective so as to purchase quieter products, cities and neighborhoods will be quieter.

Section 1. DESCRIPTION OF THE PRODUCT

For the purposes of this supplement there are two broad categories of motorcycles: street motorcycles and off-road and off-road motorcycles.

STREET MOTORCYCLES

"Street" motorcycles are defined as all motorcycles which are designed and marketed for on-road operation. This category includes street and highway motorcycles, on-road/off-road combination motorcycles, Enduro motorcycles intended for limited street operation, minicycles intended for street operation, and motor-driven cycles.

This street motorcycle category encompasses vehicles having the following characteristics:

1. Approximately 50 to 100 c.c. engines, developing from 1 to 100 horsepower.
2. Two-stroke, four-stroke, and rotary engines.
3. One to six cylinders.
4. Liquid, fan and air cooling systems.
5. Two and three wheels.
6. Light and heavy weight.
7. Shaft and chain drive.
8. Manual and hydraulic torque converter automatic transmission.

OFF ROAD MOTORCYCLES

"Off-road" motorcycles are defined as all motorcycles which are designed and marketed for off-road recreational and off-road competition use, with the exception of motorcycles designed and marketed solely for use in closed-course competition events.

This off-road category encompasses vehicles having the following characteristics:

1. 50 to 500 C.c. engines.
2. Two-stroke and four-stroke engines.
3. Single cylinder.
4. Air cooled.
5. Two and three wheels.
6. Light weight.
7. Chain drive.
8. Manual, centrifugal clutch and continuously variable (belt) automatic transmission.

Section 2. NOISE LEVEL OUTPUT INFORMATION

Definitions of Terms

NOISE: Any undesired sound.

SOUND LEVEL METER: An instrument, consisting of a microphone, an amplifier, an output meter, and frequency-weighted networks, that is used for the measurement of sound levels, in a specified manner.

DECIBEL:The intensity of a sound often abbreviated dB. The decibel scale was devised to measure the smallest difference in sound which is detectable by the human ear. Its graduations move up not in a simple arithmetic progression but in a multiple progression based on logarithmic calculations, This means that each increase of one decibel represents a much larger change of intensity than might be expected. Because of the logarithmic progression of the decibel scale, an increase of ten decibels, for example, reflects a ten-fold increase in sound energy, but is perceived as being approximately twice as loud. Thus a sound which is measured at 80 dB contains ten times the sound output and is perceived as being twice as loud as a sound that is measured at 70 dB.

dBA: An expression of sound level taking into account the response of the human ear to sound.

Noise level information is given in Table 1. When using it, please note:

1) the noise level range given for commercially available models of the product is for use as a guide only. It is not a definitive statement of noise measurements taken on all models currently available. Lower noise levels, for some models, are likely to be found.

2) when making comparisons among the noise levels of different products, it is very important that a single noise measurement method¹ is used. If this is not adhered to, very different noise levels will result and comparisons which are made may not be meaningful. Thus, in the chart the range of noise levels is expressed using one method from the known ones that are listed, to insure consistency when comparing noise level information. Selection of that particular method in no way constitutes NIGP endorsement of that method.

3) the table implies nothing in terms of product pricing. A quieter product does not necessarily cost more; in many cases, it may be less.

Measurement Procedures

Sound level measurement procedures generally prescribe instrumentation (e.g., the type of sound level meter to be used, other devices required), a description of the test site and measurement zone, a description of equipment operation (e.g. traveling on stationary mode, rpm setting), how measurements are to be made (e.g., setting of sound level meter, height and location of microphones), and general requirements (e.g., such as who should select testing equipment and conduct the tests).

1. See discussion in Section 3.

1. The U.S. EPA will soon issue maximum levels (using the EPA motorcycle noise measurement methodology) that manufacturers will be required to meet which will lower the upper limits for commercially available motorcycles of each type. The EPA motorcycle noise measurement method is slightly different than SAE 331a.

2. Most commonly used method in U.S. as of 1979;

3. Used by California highway patrol;

4. Used in Canada;

5. Slightly different than SAE J-331a

Section 3. PREPARATION OF THE PRODUCT SPECIFICATION

A good specification for any product will identify minimum performance and design requirements; list the reproducible test methods that may be used to determine compliance with these requirements; allow competitive bidding; permit an equitable contract award at the lowest possible evaluated price.

Therefore, a government seeking to purchase a quieter product should be sure that its specification describes a product that can be bid at a reasonable price by at least two, and preferably, three or more suppliers.

Noise Level Specification
The noise level portion of the product specification should contain the following three elements.

1. A maximum noise level referenced to a single measurement methodology.
2. A verification requirement, and
3. An incentive for offering products quieter than the maximum level established.

Maximum Noise Level
The maximum level should be low enough to disqualify the noisiest models on the market but high enough to insure competition among 2 or more suppliers.

In the absence of a firmly established specification, the buyer is encouraged to contact NIGP for a recommended maximum level based on an updated Table 1.

Including Sound Level Measurement Procedures in the Specifications
A buyer must reference a reproducible sound level measurement procedure whenever it specifies a noise level requirement or any other performance requirement. For example, the noise level requirement in a specification for a quieter motorcycle might say:

A copy of the complete specification will be available in the near future from NIGP.

Verifying Compliance With Specifications

There are at least two ways that governments can assure themselves that they have been offered or sold products which conform to specified requirements. One involves laboratory and field testing. The other involves vendor submission of "certified" test data.

In some instances, it may be necessary for the government or its agent (e.g., a commercial laboratory) to actually test items when they are submitted for evaluation or when received after purchase. In most instances, however, it is more practical for the government to ask a vendor to submit, with his bid, an approved third-party's written certification that the vendor's product conforms with a specified requirement. There are hundreds of private sector laboratories which could be approved to perform testing and certification services for manufacturers.

If a buyer must actually test the noise levels of product models offered in response to a "noise-conscious" invitation for bids, he or she should contact the Buy Quiet Program director at the NIGP national office for assistance, who may be able to arrange for essential testing through various cooperative programs.

Section 4. A SUGGESTED METHOD OF CONTRACT AWARD

NIGP has developed an optimal method of contract award which allows a buyer to encourage a bidder to offer a product that is even quieter than required by the specification. In effect, it tells the bidder: "For each decibel¹ that your product is quieter than the loudest product bid (in conformance with the specification), we will subtract a fixed percentage of the average actual bid price from your actual bid price. The difference will be your evaluated bid price."

Evaluated bid prices, rather than actual bid prices, are compared in the selection of the contract recipient. As in Life Cycle Costing, the bidder with the lowest actual bid price may not necessarily be the bidder with the lowest "evaluated" bid price.

To insure against paying an excessive premium for increased quietness, buyers using this optimal method of contract award can state: the purchaser will not pay a contract price more than X percent in total above the average of the actual bid prices.² This amount represents the maximum additional amount that the government is willing to pay above the average actual bid price, for each quieter product.

1. Usually (but not always) A scale. A few product methodologies may use the C scale.

2. Not to be confused with the per decibel incentive in the formula.

The formula for determining the Evaluated Bid Price (EBP) is:

EBP = P - Y% (P_AV) (N_N-N) where:

EBP = Evaluated Bid Price

P = Actual Bid Price

Y% = The percentage weight designated by the purchasing activity to "reward" the bidder for each decibel that his model is quieter than the noisier model bids.

P_AV = Average (actual) bid price of all models bid in response to the IFB

N_N = The noise level (in decibels) of the noisiest model bid in response to the IFB

N = The noise level (in decibels) of the model whose ESP is being determined

In order to illustrate the working of the formula, the bid tabulations for a purchase of quieter product X might look like this:

BIDDERS:

Assuming that the Purchasing Activity used a 2% "reward" factor for each decibel of increased quietness, the EBP for each bidder would be determined as follows:

(A) Smith Co.
EBP = $145. - .02 ($149) (76-76)
= $145. - $2.98 (0)
= $145.

(B) Roberts Co.
EBP = $154. - .02 ($149) (76-75)
= $154. - $2.98 (1)
= $151.02

(C) Jones Co.
EBP = $147. - .02 ($149) (76-72)
= $147. - 2.98 (4)
= $147. - $11.92 = $135.08

(D) Watkins Co.
EBP = $150. - .02 ($149)(76-71)
= $150. - $2.98 (5)
= $150. - $14.90
= $135.10

Based on an evaluated bid price (EBP) of $135.08, the contract should be awarded to Jones Co. (bidder "C") at its actual price of $147 per unit for furnishing quieter product X with a (maximum) noise level of 72 decibels (A Scale).

The Buy Quiet concept is new and the program is just starting. It should not be surprising, therefore, that the NIGP Data Bank, as yet, has no experience to report for these products. When experiences become known to us, the governments will be listed in this section.

Director
Buy Quiet Program
National Institute of Governmental Purchasing, Inc.
1001 Connecticut Avenue, N.W.
Suite 922
Washington, DC 20036
Tel:202-331-1357

For additional information on technical and programmatic matters relating to product noise, you may wish to contact your local or state noise control official.