Effects of noise on speech recognition: Challenges for communication by service members

Abstract

Speech communication often takes place in noisy environments; this is an urgent issue for military personnel who must communicate in high-noise environments. The effects of noise on speech recognition vary significantly according to the sources of noise, the number and types of talkers, and the listener's hearing ability. In this review, speech communication is first described as it relates to current standards of hearing assessment for military and civilian populations. The next section categorizes types of noise (also called maskers) according to their temporal characteristics (steady or fluctuating) and perceptive effects (energetic or informational masking). Next, speech recognition difficulties experienced by listeners with hearing loss and by older listeners are summarized, and questions on the possible causes of speech-in-noise difficulty are discussed, including recent suggestions of "hidden hearing loss". The final section describes tests used by military and civilian researchers, audiologists, and hearing technicians to assess performance of an individual in recognizing speech in background noise, as well as metrics that predict performance based on a listener and background noise profile. This article provides readers with an overview of the challenges associated with speech communication in noisy backgrounds, as well as its assessment and potential impact on functional performance, and provides guidance for important new research directions relevant not only to military personnel, but also to employees who work in high noise environments.

Effects of Recreational Noise on Threshold and Suprathreshold Measures of Auditory Function

“…There are a variety of data that support a relationship between suprathreshold function and exposure to noise (for recent review, see Le Prell and Clavier 20 ). Although the present study did not find significant associations between 1-year noise exposure history (L Aeq8760 ) and wave I amplitude of the ABR, or between wave I amplitude and functional measures, it remains possible that deficits may be present in those with louder, longer, or more frequent noise exposure.…”

“…14 Kujawa and Liberman have suggested that a likely functional correlate of this neural injury is difficulty understanding speech in noisy environments, 17 which has stimulated significant interest in speech-in-noise tests for use in clinical trials and other studies of hidden hearing loss. [18][19][20] More recent animal studies have shown that lower-level exposures resulting in smaller TTS deficits (<30 dB) do not result in neural pathology, 12,21,22 even when the TTS-inducing exposure has been repeated weekly over a 6week period. 23 Although specific dose-response relationships remain to be determined, when the duration of an acute exposure at a lower, previously nonpathologic, sound level was extended from 2 hours to 8 hours, neural pathology emerged with the longer duration exposure, demonstrating that both noise level and exposure duration influence the risk of synaptopathic injury.…”

“…Based on the existing data, it was hypothesized that increased levels of recreational noise may be reliably associated with both reduced ABR wave I amplitude and poorer speech-in-noise performance and temporal processing. Multiple functional tests were used to identify potential deficits in speech processing in noise backgrounds both with and without informational masking (i.e., babble background versus broadband noise (BBN) background; for recent discussion of test differences, see Le Prell and Clavier 20 ). Some evidence suggests noise exposure has the potential to affect temporal processing, [33][34][35] and thus the design also included tasks that assessed temporal summation in quiet and in a noise background, in an effort to assess potential temporal processing deficits for signals in quiet and in noise.…”

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

“…Efforts to validate self-reported difficulty using the SSQ against quantitative speech-in-noise test measures have had limited success (Banh, Singh, and Pichora-Fuller 2012; Fredriksson et al 2016). Taken together, at this time, there is no "gold standard" for either qualitative speech-in-noise surveys or quantitative speech-in-noise testing (for discussion, see Le Prell and Lobarinas 2015;Le Prell and Brungart 2016;Le Prell and Clavier 2017;.…”

Performance Evaluation of Aviation Headset in Indian Army

“…Moreover, the impairment of speech intelligibility in noisy environments can drastically reduce the performance of complex and expensive weapon systems [6][7] . There is a growing concern regarding the effects of noise and the necessity to control it.…”