Student's Self-Reported Experience of Soundscape: The Link between Noise, Psychological and Physical Well-Being.

Extensive research has shown that noise has detrimental effects on learning in classrooms, yet schools remain noisy environments. In addition, little is known about the students' insight into their subjective reaction to noise. Students' awareness of noise, as well as their perception of its effects on their affective and bodily states, remain unanswered. In the current study, the self-reported experience of noise and reaction towards noise, which was collected by way of a questionnaire, was assessed for 408 students in primary and secondary schools in Québec. Results suggest that about half of the students experience affective and bodily reactions to noise, and students who report having a negative affective reaction to noise are also more prone to report feeling this noise in their bodies. The results of this study offer a comprehensive picture of the students' subjective (affective and bodily) state in relation to noise in schools.

Method for protected noise exposure level assessment under an in-ear hearing protection device: a pilot study.

OBJECTIVE: To properly measure the effective noise exposure level of workers with hearing protection devices (HPD), the use of in-ear noise dosimeters (IEND) is increasing. Commercial IENDs typically feature one in-ear microphone that captures all noises inside the ear and do not discriminate the residual noise in the earcanal from wearer-induced disturbances (WID) to calculate the in-ear sound pressure levels (SPL). A method to alleviate this particular issue with IENDs and calculate the hearing protection level on-site is therefore proposed. DESIGN: The sound captured by an outer-ear microphone is filtered with the modelled HPD transfer function to estimate the in-ear SPL, this way part of the WIDs mostly captured by the in-ear microphone can be rejected from the SPL. The level of protection provided by the earplugs can then be estimated from the difference between in-ear and outer-ear SPLs. The proposed method is validated by comparing the outcome of the proposed WID rejection method to a reference method. STUDY SAMPLE: The detailed methods are assessed on audio recordings from 16 industrial workers monitored for up to 4 days. RESULTS: The merits of the proposed WID rejection approach are discussed in terms of residual SPL and hearing protection level estimation accuracy. CONCLUSIONS: Based on the findings, a method to integrate the proposed WID rejection algorithm in future IENDs is suggested.

An in-ear speech database in varying conditions of the audio-phonation loop.

With the rise of hearables and the advantages of using in-ear microphones with intra-aural devices, accessibility to an in-ear speech database in adverse conditions is essential. Speech captured inside the occluded ear is limited in its frequency bandwidth and has an amplified low frequency content. In addition, occluding the ear canal affects speech production, especially in noisy environments. These changes to speech production have a detrimental effect on speech-based algorithms. Yet, to the authors' knowledge, there are no speech databases that account for these changes. This paper presents a speech-in-ear database, of speech captured inside an occluded ear in noise and in quiet. The database is bilingual (in French and in English) and is intended to aid researchers in developing algorithms for intra-aural devices utilizing in-ear microphones.

Modeling Speech Level as a Function of Background Noise Level and Talker-to-Listener Distance for Talkers Wearing Hearing Protection Devices.

Purpose: Studying the variations in speech levels with changing background noise level and talker-to-listener distance for talkers wearing hearing protection devices (HPDs) can aid in understanding communication in background noise. Method: Speech was recorded using an intra-aural HPD from 12 different talkers at 5 different distances in 3 different noise conditions and 2 quiet conditions. Results: This article proposes models that can predict the difference in speech level as a function of background noise level and talker-to-listener distance for occluded talkers. The proposed model complements the existing model presented by Pelegrín-García, Smits, Brunskog, and Jeong (2011) and expands on it by taking into account the effects of occlusion and background noise level on changes in speech sound level. Conclusions: Three models of the relationship between vocal effort, background noise level, and talker-to-listener distance for talkers wearing HPDs are presented. The model with the best prediction intervals is a talker-dependent model that requires the users' unoccluded speech level at 10 m as a reference. A model describing the relationship between speech level, talker-to-listener distance, and background noise level for occluded talkers could eventually be incorporated with radio protocols to transmit verbal communication only to an intended set of listeners within a given spatial range-this range being dependent on the changes in speech level and background noise level.

In-ear microphone speech quality enhancement via adaptive filtering and artificial bandwidth extension.

Bone and tissue conducted speech has been used in noisy environments to provide a relatively high signal-to-noise ratio signal. However, the limited bandwidth of bone and tissue conducted speech degrades the quality of the speech signal. Moreover in very noisy conditions, bandwidth extension of the bone and tissue conducted speech becomes problematic. In this paper, speech generated from bone and tissue conduction captured using an in-ear microphone is enhanced using adaptive filtering and a non-linear bandwidth extension method. Objective and subjective tests are used to evaluate the performance of the proposed techniques. Both evaluations show a statistically significant quality enhancement of the noisy in-ear microphone speech with ρ<0.0001 after denoising and ρ<0.01 after bandwidth extension.

Variations in voice level and fundamental frequency with changing background noise level and talker-to-listener distance while wearing hearing protectors: A pilot study.

OBJECTIVE: Speech production in noise with varying talker-to-listener distance has been well studied for the open ear condition. However, occluding the ear canal can affect the auditory feedback and cause deviations from the models presented for the open-ear condition. Communication is a main concern for people wearing hearing protection devices (HPD). Although practical, radio communication is cumbersome, as it does not distinguish designated receivers. A smarter radio communication protocol must be developed to alleviate this problem. Thus, it is necessary to model speech production in noise while wearing HPDs. Such a model opens the door to radio communication systems that distinguish receivers and offer more efficient communication between persons wearing HPDs. DESIGN: This paper presents the results of a pilot study aimed to investigate the effects of occluding the ear on changes in voice level and fundamental frequency in noise and with varying talker-to-listener distance. STUDY SAMPLE: Twelve participants with a mean age of 28 participated in this study. RESULTS: Compared to existing data, results show a trend similar to the open ear condition with the exception of the occluded quiet condition. CONCLUSIONS: This implies that a model can be developed to better understand speech production for the occluded ear.