ABSTRACT
Previous laboratory studies with severely and profoundly hearing-impaired persons aided with behind-the-ear (BTE) hearing aids have resulted in prediction rules for insertion gain and maximum gain without occurrence of acoustic feedback. The practicability of these findings was investigated in the present field trial with 21 profoundly deaf children fitted with power BTE hearing aids. In dialogue situations without background noise, the gain control settings were in accordance with the insertion gain prediction rule, whereas preferred gain may be 10 dB lower in the presence of noise. Consistent with the prediction rule for maximum gain without feedback and the gain response of the present test hearing aid, we observed oscillation in the high-frequency range in which the children had no remaining hearing. When the high-frequency gain was reduced, sufficient low-frequency gain could be provided without feedback problems.
Subject(s)
Hearing Aids , Hearing Disorders/physiopathology , Acoustics , Auditory Threshold , Child , Feedback/physiology , Hearing Disorders/therapy , Humans , Noise/adverse effectsABSTRACT
Present-day conventional baby-alarms for hearing-impaired parents do not convey information about how the baby is feeling (happy, crying, or distressed). Consequently, the parent is forced to go to the baby to weigh up the situation visually. A new baby-alarm, FreDe 85, which determines the tenseness of the cry signal, has been tested by 10 deaf families with babies in the age range 3 to 21 months. The test families compared the illuminated pictures on the panel of the baby-alarm with the baby's situation. The parents could observe significantly different distributions of illuminated pictures in the three situations. Some families living in multi-storey flats experienced false alarms in the night, indicating the need to place the microphone closer to the baby.
