Relationship between earmould venting, comfort and feedback.
Although earmould venting is considered to make an earmould more comfortable, whether it does so remains to be proven in hearing-aid users. A hundred and six patients were sequentially fitted with a hearing aid in a randomized order with an unvented, a 0.8 mm vented or a 2 mm vented mould and questioned about various aspects of discomfort at the end of each trial period. The three moulds were equally uncomfortable (approximately 17% overall), moist (approximately 34% overall) and associated with an itchy sensation (approximately 36% overall). However, a 0.8 mm and a 2 mm vent significantly reduced the sensation of blockage from 35 to 22% (P less than 0.05) and 13% (P less than 0.001) respectively. A potential disadvantage of venting is feedback, but patients' reports of this can be confused with feedback due to incorrectly inserting the mould. A separate study showed that a 2 mm vent might cause feedback in approximately 10% of patients when used in conjunction with behind-the-ear aids whose maximum gain was 45 dB, but only when the gain was at 42 dB or greater.
MacKenzie
K
K
Department of Otolaryngology, University of Glasgow, Royal Infirmary.
Browning
G G
GG
McClymont
L G
LG
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003258:Consumer Behavior; D005246:Feedback; D005260:Female; D006310:Hearing Aids / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011897:Random Allocation