ABSTRACT
BACKGROUND: The acceptable noise level (ANL) is a measure of willingness to listen to speech in the presence of background noise and is thought to be related to success with amplification. To date, ANLs have only been assessed over short periods of time, including within a session and over a 3-week and 3-month time period. ANL stability over longer periods of time has not been assessed. PURPOSE: The purpose was to examine the stability of ANL over a 1-year time period. RESEARCH DESIGN: A repeated-measures, longitudinal study was completed. STUDY SAMPLE: Thirty young adults with normal hearing served as participants. The participants were tested at two different sites. DATA COLLECTION AND ANALYSIS: Two trials of most comfortable listening levels (MCLs), background noise levels (BNLs), and ANLs were assessed for each participant during three experimental sessions: at 0 months, 6 months, and 1 year. RESULTS: Two-way repeated-measures analysis of variances revealed no significant change in MCLs, BNLs, or ANLs within a session or over a 1-year time period. These results indicate that ANLs remain stable for 1 year in listeners with normal hearing. CONCLUSIONS: The finding that the ANL is stable over a longer period of time supports the theory that the ANL is an inherent trait of the listener and mediated at in the central auditory nervous system.
