The effects of noise exposure and musical training on suprathreshold auditory processing and speech perception in noise

Abstract

Recent animal research has shown that exposure to single episodes of intense noise causes cochlear synaptopathy without affecting hearing thresholds. It has been suggested that the same may occur in humans. If so, it is hypothesized that this would result in impaired encoding of sound and lead to difficulties hearing at suprathreshold levels, particularly in challenging listening environments. The primary aim of this study was to investigate the effect of noise exposure on auditory processing, including the perception of speech in noise, in adult humans. A secondary aim was to explore whether musical training might improve some aspects of auditory processing and thus counteract or ameliorate any negative impacts of noise exposure. In a sample of 122 participants (63 female) aged 30-57 years with normal or near-normal hearing thresholds, we conducted audiometric tests, including tympanometry, audiometry, acoustic reflexes, otoacoustic emissions and medial olivocochlear responses. We also assessed temporal and spectral processing, by determining thresholds for detection of amplitude modulation and temporal fine structure. We assessed speech-in-noise perception, and conducted tests of attention, memory and sentence closure. We also calculated participants' accumulated lifetime noise exposure and administered questionnaires to assess self-reported listening difficulty and musical training. The results showed no clear link between participants' lifetime noise exposure and performance on any of the auditory processing or speech-in-noise tasks. Musical training was associated with better performance on the auditory processing tasks, but not the on the speech-in-noise perception tasks. The results indicate that sentence closure skills, working memory, attention, extended high frequency hearing thresholds and medial olivocochlear suppression strength are important factors that are related to the ability to process speech in noise.

Individual differences in the attentional modulation of the human auditory brainstem response to speech inform on speech-in-noise deficits

“…Moreover, we did not find a significant pairwise correlation between any of these behavioural and objective measures. This accords with recent large-cohort studies that have not found a correlation of proposed measures of cochlear synaptopathy to the lifetime noise exposure of the participants or their speech-in-noise perception 37,71,72 . This may suggest that either cochlear synaptopathy has little influence on auditory difficulty or that it has no significant prevalence, at least in normal-hearing people.…”

‘Normal’ hearing thresholds and fundamental auditory grouping processes predict difficulties with speech-in-noise perception

“…That sub-clinical variability in audiometric thresholds at these frequencies might predict speechin-noise perception has often been overlooked: Several previous studies have assumed that subclinical variability in audiometric thresholds do not contribute to speech-in-noise perception and have not explored this relationship (e.g., Alvord, 1983;Kumar et al, 2012). Of those that have tested the relationship, two found a correlation (Schoof and Rosen, 2016;Yeend et al, 2017), although one of these (Yeend et al, 2017) included participants with mild hearing loss and it is possible that these participants were responsible for the observed relationship. Two others found no correlation but restricted the variability in their sample by either imposing a stringent criterion on 'normal' hearing less than 15 dB HL or considering only young participants aged 18-30 years (Oberfeld and Klöckner-Nowotny, 2016).…”

Effects of noise exposure on auditory brainstem response and speech-in-noise tasks: a review of the literature

“…Although the OSHA regulations do not require testing at 8 kHz or above, poorer high-frequency hearing has been reported in workers exposed to occupational noise. Deficits have been reported within the extended high-frequency (EHF) range of 10 kHz and above in workers exposed to occupational noise (Hallmo, Borchgrevink, and Mair 1995;Korres et al 2008;Riga et al 2010;Mehrparvar et al 2014), personal audio system device users (Le Prell et al 2013;Sulaiman, Husain, and Seluakumaran 2015;Kumar et al 2017), those with a history of musical training (Schmidt et al 1994;Gonçalves et al 2013;Liberman et al 2016), frequent concert goers (Grose, Buss, and Hall 2017), those with acoustic trauma during military service (Balatsouras, Homsioglou, and Danielidis 2005;Buchler, Kompis, and Hotz 2012) and individuals with higher lifetime noise exposure (Prendergast et al 2017a;Yeend et al 2017). NIOSH recommends testing through 8 kHz.…”