Publication date: Available online 17 September 2018
Source: American Journal of Otolaryngology
Author(s): Massimo Ralli, Antonio Greco, Marco De Vincentiis, Adam Sheppard, Giampietro Cappelli, Ilaria Neri, Richard Salvi
Abstract
Purpose
One of the most common complaints among the elderly is the inability to understand speech in noisy environments. In many cases, these deficits are due to age-related hearing loss; however, some of the elderly that have difficulty hearing in noise have clinically normal pure-tone thresholds. While speech in noise testing is informative, it fails to identify specific frequencies responsible for the speech processing deficit. Auditory neuropathy patients and animal models of hidden hearing loss suggest that tone-in-noise thresholds may provide frequency specific information for those patients who express difficulty, but have normal thresholds in quiet. Therefore, we aimed to determine if tone-in-noise thresholds could be a useful measure in detecting age-related hearing deficits, despite having normal audiometric thresholds.
Materials & methods
We tested this hypothesis by measuring tone-in-noise thresholds in 11 Old (62.4 ± 5 years) and 21 Young (23.1 ± 2.2 years) patients with clinically normal thresholds. Tone thresholds were measured in a quite sound field, then in 20, 30 and 40 dB HL broadband noise.
Results
Despite having normal hearing (thresholds ≤25 dB HL), the Old patients had significantly worse tone-in-noise thresholds than the Young patients at 0.125, 4, and 8 kHz. Linear regression analysis showed that the growth of masking in Old and Young patients was nearly identical at all frequencies. However, the amount of masking at low and high frequencies was typically 10–18 dB greater in the Old patients compared to the Young, except near 1 kHz. The frequency-dependent changes in masking are discussed in the context of a "line busy" model and temporal bone studies of auditory nerve fiber loss.
https://ift.tt/2OwwVdy
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου