FAQ: the most comon questions & answers
for Danalogic i-FIT

1. Is the calibration test signal for the DFS the same as for Danalogic 6?
2. What are the attack and release times for the compression in Danalogic
      i-FIT?
3. What are the beep frequencies?
4. How many days data does Danalogic i-FIT store?
5. Do we need written consent from the patient when using data logging?
6. Does the VC revert back to the default level when the battery door is
      opened/closed?
7. What are the criteria for the Situation Anaylser?
8. Why does a low-frequency roll-off occur when you activate a directional microphone?
9. What are the limitations of bass boost compensation with traditional directionality?
10. Danalogic i-FIT now has an omnidirectional response in the low frequencies. Why is this important?
11. Why do the low and high frequencies need to be treated differently, and how does this relate to the natural ear?
12. What is the importance of maintaining the natural time constants or interaural time differences (ITDs), and what are the consequences if we do not?
13. How is band-split directionality different from fixed directionality?
14. Why is the concept of band-split directionality important?
15. When you change the Directional blend, is there any change in the low frequency intensity?
16. How is band-split directionality calculated for each individual ear?
17. What is the significance of Intelligent Directionality with Autofocus?
18. When using Autofocus, how much does sound intensity (in dB) that is received in the front need to change before there is an adaptation in beam width?
19. What are the attack and release times of Autofocus?
20. Why does a time difference exist between attack and release times?
21. What do the settings on the Feedback Eliminator represent?
22. What Feedback Eliminator setting should be chosen?
23. If it is suspected that a fitting may be unstable, what are some possible causes?
24. Is there an extended bandwidth with Danalogic i-FIT?

1. Is the calibration test signal for the DFS the same as for Danalogic 6?
Yes, the procedure, duration and test level is the same.

2. What are the attack and release times for the compression in Danalogic i-FIT?
Attack 12 ms / release 120 ms for the lowest frequencies (up to 250 ms) and attack 5 ms / release 70 ms for the rest.

3. What are the beep frequencies?
The beep frequencies instruments are: Low battery warning:1560 Hz. Program change: 975 Hz. Smart start: 975 Hz. VC change: 1300 Hz. VC limits: 710 Hz.

4. How many days data does Danalogic i-FIT store?
The data logging function stores data from the most recent 100 days of patient usage.

5. Do we need written consent from the patient when using data logging?
Our understanding is that as long as you have made the patient aware of data logging you do not need written consent. However you may want to confirm this against your internal Trust polices

6. Does the VC revert back to the default level when the battery door is opened/closed?
It will revert to the default level.

7. What are the criteria for the Situation Anaylser?
Input level SPL + speech detected. Speech detected is based on analysis of the power spectrum of the input (signal-to-noise-ratio).

Quiet = Less than 54dB.
Softspeech = speech only less than 60dB.
Loud speech = speech only, more than 60dB.
Soft speech in noise = speech & noise, less than 75dB.
Loud speech in noise = speech & noise, more than 75dB.
Soft noise = noise only, less than 75dB.
Loud noise = noise only, more than 75dB.

8. Why does a low-frequency roll-off occur when you activate a directional microphone?
Directional microphones are less sensitive in low frequency regions than omni-directional microphones.

9. What are the limitations of bass boost compensation with traditional directionality?
Bass Boost compensation is used to counter loss of far-field low-frequency sounds caused by a directional microphone. That compensation leads to over-amplifying near-field sounds (i.e., the proximity effect). The noise floor is increased, which can lead to decreased speech intelligibility.

10. Danalogic i-FIT now has an omnidirectional response in the low frequencies. Why is this important?
Because it resolves the limitations of directionality with little sacrifice. Audibility and comfort are restored into the intelligibility-centered framework of directional technology.
Look at the natural ear and the head-related transfer function (HRTF). There is a difference in the high frequency directional pattern through head shadow than for low frequencies, which is more of an omnidirectional pattern.

11. Why do the low and high frequencies need to be treated differently, and how does this relate to the natural ear?
Interaural time differences (ITDs) are informative in lower frequencies; interaural level differences (ILDs) are informative in higher frequencies. By using a similar, fixed processing scheme across a bilateral fitting, we can maintain important ITD cues in the lower frequencies.
Looking at the natural ear and the head-related transfer function (HRTF), the high frequency patterns are more directional, and the low frequencies are more omnidirectional.

12. What is the importance of maintaining the natural time constants or interaural time differences (ITDs), and what are the consequences if we do not?
Natural time constants are important to spatial hearing, spatial awareness, and localization, and these elements are impaired if natural time constants are not maintained.

13. How is band-split directionality different from fixed directionality?
Most fixed directionality settings are based on simple mathematical properties; band-split directionality is based on the natural acoustic properties of the open ear.

14. Why is the concept of band-split directionality important?
For those patients with more than a mild hearing loss, it offers a more natural listening experience.

15. When you change the Directional blend, is there any change in the low frequency intensity?
No. This will cause the hearing instrument to have a larger or smaller omni directional range, but there is no intensity change.

16. How is band-split directionality calculated for each individual ear?
The pre-selection of a Directional blend setting is based on the individual’s audiogram and hearing instrument style.

17. What is the significance of Intelligent Directionality with Autofocus?
It improves upon adaptive directionality by making automatic adjustments to the beam width

18. When using Autofocus, how much does sound intensity (in dB) that is received in the front need to change before there is an adaptation in beam width?
The narrowest beam width is 75dB SPL, and above this the beams will not narrow any further. The widest beam width is at 55dB SPL, and below this the beams will not widen any further. The beam width has the opportunity to maneuver in between these values.

19. What are the attack and release times of Autofocus?
The attack time takes approximately ten seconds to go from a wide to narrow beam width. The release time takes approximately two seconds to go from a narrow to wide beam width.

20. Why does a time difference exist between attack and release times?
The difference in attack and release times provides the user with as much information of the signal as possible. If the instrument switches into a narrow beam too quickly or stays in a narrow beam too long, the user may lose important cues for spatial awareness, and sound information would be restricted to information only within the active beam. Utilizing different attack and release times is a more conservative approach, but the benefit is that more useable sound information will be obtained for the user.

21. What do the settings on the Feedback Eliminator represent?
Regardless of how it is set to (mild, moderate or strong) the actual gain reductions will be the same. The different settings tell how often there is going to be a gain reduction, not how much gain reduction there will be. With a mild setting, the sensitivity is weaker, and with a strong setting, the sensitivity is at its highest.

22. What Feedback Eliminator setting should be chosen?
The setting is automatically calculated when DFS is calibrated. If a patient experiences little to no feedback in all situations, nothing needs to be done. If a patient has risk of frequent feedback in many situations use the moderate or strong setting.

23. If it is suspected that a fitting may be unstable, what are some possible causes?
Gain in the Aventa software is set too high.
Model of hearing instrument may be incorrect for the degree of hearing loss.
Custom hearing instrument shell or BTE earmold does not fit properly.
Incorrect style of earmold was chosen.
Custom hearing instrument or BTE earmold is too large.
Patient is not properly seating hearing instrument and/or earmold.

24. Is there an extended bandwidth with Danalogic i-FIT?
Yes. The bandwidth of the i-FIT 71 BTE extends beyond 7000Hz: