ESPô Quick Start Guide

(Version 2.0, October 1, 1998)

James, Anderson & Associates, Inc.

What Is Sound Exposure Profiling?

Sound is dynamic. Rarely is it completely steady. It is modified by its environment and its medium. As a result, the task of estimating a personís noise exposure is not always very simple. Changing job tasks, employee mobility, operator rotation, or simply the variety of machinery can all have an effect on a personís noise exposure level. However, one method of monitoring excels in this kind of environment: sound exposure profiling.

By utilizing fractional computation formulas, profiling takes the different sound levels that a person is exposed to over the course of the work day and computes an eight-hour TWA exposure. Since these sound levels are associated with the various job tasks that an employee must perform, noise exposures are easily identified and measured.

This section of the guide is designed to provide a brief overview of the profiling technique in order to give the user of ESPô a better understanding of how the program works. The profiling technique can be broken down into three basic steps: Job Analysis, Sound Sampling, and Exposure Computation. Letís take a look at this method in more detail.

Job Analysis

The first step in sound exposure profiling is the job analysis. The purpose of this step is to identify all of the significant job related tasks that the employee will perform in the course of the work day. In doing so, all possible exposure sources are accounted for in the profile.

Analysis of the job involves observation and communication. By observing the job, one can identify the various tasks the employee typically performs in a work cycle. Communication with the employee is needed in order to be certain that isolated tasks are not overlooked or missed altogether. Such tasks may occur at various points throughout the day or only once.

Jobs that rely on a repetitive cycle are often easier to analyze than jobs that are non-cyclical. Jobs that are non-cyclical, or that do not require the employee to interact with each production cycle, requires greater involvement from the employee to assist in identifying the job tasks.

Sound Sampling

After each of the separate job tasks that are identified, the average sound level is measured using an integrating sound level meter. This kind of sound meter enables one to capture the sound being generated over a certain period of time and with repeated measurements. The average sound level is taken by running the meter while the specific task is performed--say, task #1. When the employee begins the next task in the series (task #2), the meter is paused to prevent sound waves associated with task #2 and the remaining tasks from being integrated into the measurement for task #1. Figure 1 illustrates this concept.

Figure 1: This chart shows the sound levels associated with a cyclical operation. The gray shading indicates the portion of the cycle that is being monitored in association with a particular task. Notice that the meter runs only when that task is performed.

In order to obtain a confident sample, the measurement period needs to be long enough to achieve a stable average for a given task. This is accomplished by repeating the measurement over several cycles, and in most cases, three cycles are sufficient to acquire a reliable sample. Tasks that are not part of the normal routine of activities are sampled also.

Exposure Computation

Next, the amount of time the employee spends performing each job task is estimated, extrapolating for the entire work shift. After all of the tasks, their associated sound levels, and time durations are obtained the 8-hour TWA is finally computed.

The following formulation is used to calculate the TWA:

where "C" indicates the time spent performing a given task at a particular sound level, and "T" stands for the allowable time at that particular sound level according to Table G-16a of the OSHA Noise Standard. The information collected for the job profile provides the "C" values and the reference point for the "T" values.

Thus, profiling is the first step and critical stage in determining the sound exposure of an employee. The data from the employee profile is what is used to construct the Employee Sound Profile.

Introduction to ESPô

ESPô is the Employee Sound Profiler. It computes an 8-hour, Time-weighted Average (TWA) in decibels for employees of a particular job function. Sound measurement data obtained using a job profiling technique (see above) are entered into this program to calculate a TWA. This manual is designed to quickly familiarize the user with the various features of this noise exposure calculator.

ESPô Installation

From a diskette:

1. Insert the install diskette into the floppy drive. Using File Manager or Windows Explorer, locate the file called setup2f.exe and double click on it.

2. The setup program will ask for a password. Type in the password enclosed with diskette or follow the instructions on the Safe@Work website (

3. Upon completion of the installation routine, an ESPô icon will appear in the HearSaf Windows group.


Please register your copy of the ESPô program with James, Anderson and Associates, Inc. A registration form and instructions are included under the HearSaf Windows group. Forms may be mailed or faxed to JAA, Inc. See registration instructions for details.

Using ESPô

The following sections explain the basic operation of ESPô.

Starting ESPô

1. Locate the ESPô icon from the HearSaf Windows group.

2. Double click the icon to start the program.

Opening a Sound Exposure Database

To open one of the pre-installed databases:

1. Start ESPô.

2. Go to the File menu and click Open File. ESPô will display a table of pre-installed databases.

3. Using the mouse or arrow keys, highlight the name of the database to open; e.g. Avatar Products Sample Database.

4. Click the Open File button in the lower right-hand corner.

Viewing a Sound Exposure Profile

To view one of the profiles:

1. Using the mouse or arrow keys, highlight a profile.

2. Click the Change button at the bottom of the table.

3. ESPô will display the profile view screen.

Note some of the information contained in a profile. Exchange rate, criterion level, group name, shift, and job function. In the lower half is the list of job tasks that are performed by the employee of this job function. Notice that the first column describes the task, the second column shows the amount of time the employee spends performing the task, and the third column contains the average (Lavg) sound level that the employee is exposed at when performing the task. The other columns provide minimum, maximum, and peak sound levels, as well as the dose for each of the tasks. The boxes at the bottom of the profile provide the shift length, TWA, and cumulative exposure dose level.

Hearing Protection Evaluation

When an exposure profile is created, ESPô automatically computes an NRR (Noise Reduction Rating) for the profile based upon pre-established criteria which are changeable to accommodate various requirements. Thus, the user may "customize" the NRR for a particular operation according to pertinent factors.

For example, the user may modify the NRR by adjusting for derating of hearing protectors by a certain percentage. Or it is possible to change the NRR factor from 7 dB (OSHA/EPA) to some other value such as 0 dB (ANSI S12.6B) or 10 dB (Mexico).

To access the NRR parameters:

1. Using the mouse or arrow keys, highlight a profile.

2. Click the Change button at the bottom of the table.

3. ESPô will display the profile view screen.

4. Click the tab marked Hearing Protection Evaluation. ESPô displays the current settings and the calculated NRR for the particular profile.

5. Change the desired parameter(s) and the NRR will automatically be updated to reflect the new settings.

Experimentation: Altering a Sound Exposure Profile

ESPô is a dynamic exposure calculator that allows for experimentation at key points in the exposure computation process. As a result, the user is able to monitor the effects of changing variables on the overall TWA exposure value.

To make a change or to experiment with a profile:

1. Open the profile record by highlighting it and clicking on the Change button.

2. To change the exchange rate or criterion level simply click on the appropriate field. Notice how the TWA and/or cumulative dose is affected by changing these values.

3. To change the Lavg or duration of a particular task, highlight the task and click the Change button.

4. Use the arrow buttons to raise or lower the values. (Note: Changing the Lmin, Lmax, or Lpeak values will not have an effect on the overall TWA level.)

5. After making the changes click the OK button.

Adding Profiles

To add a new profile to a database:

1. After opening the database, click the Insert button. ESPô will display a new profile form.

2. Enter the date directly, or select the date from the calendar button.

3. Set the exchange rate and criterion level.

4. Enter the group code and name, operation, shift, and job function.

5. Next, click on the Insert button to add job tasks. ESPô will open a task screen.

6. Type in a description of the task being performed.

7. Enter the duration the employee will spend performing the task (in hours).

8. Enter an Lavg, Lmin, Lmax, and Lpeak. A note may also be entered in the Memo field. (Note that minimum, maximum and peak sound levels are not required for computing the TWA value.) Click the OK button when finished.

Continue to add tasks to the profile until the profile is complete. Notice how the shift length, TWA, and cumulative dose fields automatically are updated with each entry. To save the profile, click the OK button.

Printing Reports

ESPô is equipped with two different report formats from which the data can be viewed. To view either of these reports:

1. Open the database.

2. Click either the Detail Report button or the Summary Report button located in the top right window.

3. ESPô will generate the report and display it in a preview screen.

4. Click the printer icon at the top of the screen to run the report to the printer.

The report can also be generated to a text file by clicking the "T" button at the top of the screen.

Detail Report

The Detail Report gives all of the sound exposure profile information including the task information. It is sorted by group code and lists the Job Function Description, Operation Number, Shift, Exchange Rate, Criterion Level, and the hearing protection settings. Below this are listed each of the profile tasks along with the Duration, Lavg, Lmin, Lmax, Lpeak, and dose. The TWA and Cumulative Dose level are given at the bottom of the profile table.

Summary Report

The Summary Report lists each of the sound exposure profiles by group code. It gives only the main information from the profile such as Job Function Description, Operation Number, TWA, Shift, Dose, NRR, and the hearing protection settings.

Data Query

ESPô comes equipped with an advanced sorting feature. By using the various query functions, the user can view specific data and print them for use in a hearing safety program. ESPô utilizes QBE (Query By Example) commands that allows the user to select a specific group code, job function, or a particular noise exposure range.

To activate the query function:

1. Open the database.

2. Click the Start Query Button located in the top left corner of the window.

3. ESPô will display the QBE form.

4. Select the kind of search function to be performed by clicking on the appropriate button at the top the form. The table below describes the function of each button.

5. After selecting the type of search, click on the data field in which the search is to be performed and enter a value.

6. Click the OK button to begin the query. ESPô will display the results of the query in the browse table.

Example Query

Viewing only the profiles with a TWA greater than 90 dB(A):

1. Click the Start Query Button to open the QBE form.

2. Select the ">" button at the top of the form.

3. Click inside the Profile TWA box near the bottom of the form.

4. Type in "90" in the box.

5. Click the OK button.

6. ESPô will display only the profiles that have a TWA greater than 90 dB(A). You should see the following screen. Note that the current query is displayed above the table. This way you will always know what you are viewing.

Now, try continuing the query further by:

1. Clicking the Edit Query button located in the top left corner. ESPô will display the current query parameters.

2. Click the Continue Query button. ESPô displays the QBE form again.

3. Click the "And" button.

4. Click the "=" button.

5. Click inside the Group Code box and type in "100".

6. Click the OK button.

7. ESPô will display only the profiles that have a TWA greater than 90 dB(A) that are in group code 100.

Printing a Query

The results of a query can also be printed using one of the two reports discussed above. After running the query, simply click on either of the report buttons. ESPô will include only those records which match the QBE in the report.