Will Natural Directionality II be more difficult to fit to older patients?
Not necessarily. Approximately 70-95% of the variability in speech-recognition performance can be attributed to variations in hearing loss. The remaining variability can be accounted for by differences in cognitive processing. Central auditory processing disorders (CAPDs) appear to play a very minor role in speech recognition among the elderly.
What is the approximate adaptation period for Natural Directionality II?
Data has shown that asymmetric microphone mode settings are more comfortable than for other directional microphone settings. However, as with any new hearing aid fitting, patients may require 2-4 weeks’ acclimatization time.
How does Natural Directionality II apply to open vs. closed fittings?
The amount of directional benefit with a directional microphone may be diminished with an open fitting (i.e., the lack of low-frequency in an open fitting reduces the directivity index). Compared to bilateral directional settings, the directional benefit with Natural Directionality may be slightly less.
Can Natural Directionality II be used for children?
It is speculated that Natural Directionality II may be advantageous due to the directional advantage and increased audibility. However, clinical trials thus far have only been conducted on adults.
Why is Natural Directionality II better than if someone was using a set of directional hearing instruments, with one set in a fixed directional mode and one set in an omni-directional mode?
With Natural Directionality II, the low frequency time constants in each ear are synchronized. This allows for maintenance of low-frequency cues important for sound quality and spatial listening abilities.
What are examples of cases were Natural Directionality II may not be the best solution for a patient?
Natural Directionality II may not be optimal for persons with unilateral deafness; for those who do not benefit from binaural amplification, such as with some VIIIth nerve pathologies; and for patients with bilateral hearing loss that will only wear one hearing instrument for any reason.
What about patients who are rarely in challenging situations with competing noise?
Patients in these situations will still receive benefit from Natural Directionality II, but it is also fair to say that in situations such as this, there may be more options for effective fitting solutions than for patients that often are in difficult listening environments.