Within the Scaling setup menu, measuring parameters can be adjusted. 

The Functions in Detail:

Loudness Scaling Tab: Adjust the signal parameters: signal type, transducers, signal duration, etc.

• Round Up/down: Make approximations of the loudness levels in the manual or automatic modes. Approximations can be made between 1.5 and 10 dB. The default setting is 5 dB. When the dynamic range of the patient is small, a smaller approximation is recommended to ensure an appropriate number of measured points between the patient's thresholds and UCLs.
• Audio Transducers: Select the transducers to be used during testing. The open headphones (K1000) are recommended because they combine the benefits of soundfield speakers and headphones because ear specific information can be obtained. Measurements can also be performed with soundfield speakers or insert earphones, but the corresponding transducers have to be available and connected to the ACAM System. The calibration of the AHA system has a default setting of open headphones or soundfield speakers.
• Signal: Select the signal to be played during the scaling procedure. The default signal is narrow band noise; research has shown this signal to be the most optimal.       For research purposes, warbled pure tones or narrow band noise with a time structure can be used. External signals can only be played when a control file is available. Refer to control file information below for more information. 
• Background: This function is not currently enabled.
• Measurement: Select a <1-step> or <2-step> scaling procedure. It is also possible to set a message prompt to appear prior to manual presentation. The customer dialog on/off can also be selected. Please refer to the "Scaling: Operation" section for more information.
• If measurement value is available: Select the ACAM System function after a second measurement value is obtained. A two-stage scaling procedure is recommended; it requires more time, but provides more accurate measurements. The one-stage scaling procedure is only recommended in specific cases. Please refer to the "Scaling: Operation" section for more information.
• Frequency and level query: If this option is selected the query dialog is enabled in the manual measurement mode and a query of the frequency and the level is performed before the measurement begins.
• Open patient dialog: If your computer is equipped with more than one monitor and the second monitor is designed as a touch screen, the patient can manually enter  the scaling statements independently. Please refer to the section "Scaling: Operation" for more information. 
• <Proceed> button: In the patient dialog window the <Proceed> button can be hidden (Figure 207). The patient can skip the signal being played by selecting the <Proceed> button. This function will play the next test signal in the series. It is recommended that the <Proceed> button be hidden or disabled.

Figure 207: Scaling patient dialog window, with <Proceed> button shown and hidden

• Position enter dialog automatically: Disable this function when you do not want bidirectional jumping of the enter dialog box during the measurement. If this function is not disabled, the dialog box will show the auditory range.
• Signal duration: Select the presentation time of the measurement signal. The default is set at 1.5 seconds and the range for selection is 1 - 3 seconds.
• Amplitude modulation: The modulation frequency and the modulation index may be adjusted here.The amplitude modulation feature is typically disabled, but it may be a useful function for research purposes.

Scaling representation and tools tab:

• Auditory fields: Select the minimum number of measured points required to generate a loudness function and graphical display (Figure 208).

Figure 208: Example of loudness function graphical display

• Calculation if at least: Select the minimum number of measured points required in order to generate a loudness function; 3,4,5,6 or 7 measured points are available. A value less than 4 creates an inexact loudness function. It is recommended that 4 or 5 be used as the minimum number of values selected for each auditory range. This will create a reliable and precise curve.
• General: Select whether or not to display the measuring limits and tone audiogram. For more information see the section "Scaling: Operation."
• Hearing aid measurement: Scaling without hearing aids, requires hearing aid gain measurements. The parameters of these measurements can be adjusted in the hearing aid measurement section. The level values for this measurement can later be used as correction values. For example select: start at 40 dB, end at 90 dB, and increment 5 dB. The hearing aid will be measured at 40, 45, 50, 55, 60, 65, 70, 75, 80, 85 and 90 dB. Only the measured parameters are available for further processing.
• Pauses: Pauses can be made before and during the measurements. This is a useful feature for hearing aids with slow compression. An increase of these calues can improve measuring quality. Select values of 1000 ms before the measurement and a minimum of 200 ms during the measurement. Before the measurement settings will determine the amount of time it will take for the first measurement signal to play. During the measurement settings will determine the amount of time to be allotted for each pause occurring between the measurements. 

Scaling Test Series Tab:

Scaling test series:

• Selection of hearing fields: Select the auditory ranges to be measured and disable the auditory ranges not to be measured.
• Measurement rules: Test series are generated within the training mode or actual measurement scaling mode. Adjust the test series parameters here.
• Measured value limit: The levels specified can not be exceeded or undershot.
• Use control file: AHA procedures can be manipulated using a control file. Please refer to the section: "Technical Information" for more details.
• Selection of hearing fields: Select the auditory ranges to be measured and disable the auditory ranges not to be measured. It is recommended to not use the auditory ranges of 6000 and 8000 Hz because hearing aids do not process information at these frequencies. 
• Measuring directives: Test series are generated within the training mode or actual measurement scaling mode. Adjust the test series parameters here. Minimum and maximum differences between measured points (for generation of the test series) can be specified. These values generate test series where the level may jump and any frequency may be presented. Parameter changes can affect the reliability of measurements. Specifically, this can occur when the difference between the previous and current signals is too small because the patient may be able to make comparisons between the two. For more information please refer to the section: "Scaling: Introduction."
• Default values are:
• Minimum difference to the previous level: 5dB
• Maximum difference to the previous level: 60dB
• Minimum difference to the previous frequency: 1
• Maximum difference to the previous frequency: 8
• Number of measured points: As described previously, present a minimum of 4 measured values per auditory range so that a reliable loudness function can be calculated. Presenting less signals can lead to a less reliable function, but presenting more signals can increase the presentation time.
• Measured value limit: The levels specified can not be exceeded or undershot.
• Use control file: AHA procedures can be manipulated using a control file. Please refer to the section: "Technical Information" for more details. Using a control file allows you to play your own signals for the scaling procedures; this may be beneficial for research purposes.