scholarly journals The effect of hearing protection devices on speech intelligibility of Persian employees

2020 ◽  
Author(s):  
Mina Karami ◽  
Mohsen Aliabadi ◽  
Rostam Golmohammadi ◽  
Morteza Hamidi Nahrani

Abstract Objective: This study aimed to investigate the effect of hearing protection devices (HPDs) on speech intelligibility in Persian work environments. Three current earmuffs and three earplugs and one of the prototypes of molded earplug were tested on 15 male subjects which were randomly selected. The noise reduction of HPDs was measured based on the Real Ear Attenuation at Threshold (REAT) method. Speech intelligibility during using HPDs was determined based on the speech discrimination score (SDS) at two signal to noise (S/N) ratios (0 and +5). Data were analyzed using SPSS 22.Results: The actual to nominal noise reduction rating values were from 47% to 84% for HPDs. At two S/N ratios, no significant differences were observed in speech intelligibility using HPDs (p >0.05). At S/N ratio=0, the speech intelligibility descriptively has been only improved by using common earmuffs up to 9.07 %. There was a significant difference up to 21.27% in speech intelligibility for proposed molded earplugs at S/N ratio=0 (p <0.05). Increasing the HPDs' noise attenuation values led to an increase in speech interference (p <0.05). The HPDs with the minimum required noise attenuation while maintaining acceptable speech intelligibility should be worn by employees exposed to medium noise levels.

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Mina Karami ◽  
Mohsen Aliabadi ◽  
Rostam Golmohammadi ◽  
Morteza Hamidi Nahrani

Abstract Objective This study aimed to investigate the effect of hearing protection devices (HPDs) on speech intelligibility in Persian work environments. Three current earmuffs and three earplugs and one of the prototypes of molded earplug were tested on 15 male subjects which were randomly selected. The noise reduction of HPDs was measured based on the Real Ear Attenuation at Threshold (REAT) method. Speech intelligibility during using HPDs was determined based on the speech discrimination score (SDS) at two signal to noise (S/N) ratios (0 and + 5). Data were analyzed using SPSS 22. Results The actual to nominal noise reduction rating values were from 47 to 84% for HPDs. At two S/N ratios, no significant differences were observed in speech intelligibility using HPDs (p > 0.05). At S/N ratio = 0, the speech intelligibility descriptively has been only improved by using common earmuffs up to 9.07%. There was a significant difference up to 21.27% in speech intelligibility for proposed molded earplugs at S/N ratio = 0 (p < 0.05). Increasing the HPDs' noise attenuation values led to an increase in speech interference (p < 0.05). The HPDs with the minimum required noise attenuation while maintaining acceptable speech intelligibility should be worn by employees exposed to medium noise levels.


2020 ◽  
Author(s):  
Mina Karami ◽  
Mohsen Aliabadi ◽  
Rostam Golmohammadi ◽  
Morteza Hamidi Nahrani

Abstract Objective: This study aimed to investigate the effect of hearing protection devices (HPDs) on speech intelligibility in Persian work environments. Three current earmuffs and three earplugs and one of the prototypes of molded earplug were tested on 15 male subjects which were randomly selected. The noise reduction of HPDs was measured based on the Real Ear Attenuation at Threshold (REAT) method. Speech intelligibility during using HPDs was determined based on the speech discrimination score (SDS) at two signal to noise (S/N) ratios (0 and +5). Data were analyzed using SPSS 22.Results: The actual to nominal noise reduction rating values were from 47% to 84% for HPDs. At two S/N ratios, no significant differences were observed in speech intelligibility using HPDs (p >0.05). At S/N ratio=0, the speech intelligibility descriptively has been only improved by using common earmuffs up to 9.07 %. There was a significant difference up to 21.27% in speech intelligibility for proposed molded earplugs at S/N ratio=0 (p <0.05). Increase the HPDs' noise attenuation values lead to increase interference in the speech (p <0.05). The HPDs with the minimum required noise attenuation while maintaining acceptable speech intelligibility should be worn by employees exposed to medium noise levels.


2020 ◽  
Author(s):  
Mina Karami ◽  
Mohsen Aliabadi ◽  
Rostam Golmohammadi ◽  
Morteza Hamidi Nahrani

Abstract Objective: This study aimed to investigate the effect of hearing protection devices (HPDs) on speech intelligibility in Persian work environments. Three current earmuffs and three earplugs and one of the prototypes of molded earplug were tested on 15 male subjects which were randomly selected. The noise reduction of HPDs was measured based on the Real Ear Attenuation at Threshold (REAT) method. Speech intelligibility during using HPDs was determined based on the speech discrimination score (SDS) at two signal to noise (S/N) ratios (0 and +5). Data were analyzed using SPSS 22.Results: The actual to nominal noise reduction rating values were from 47% to 84% for HPDs. At two S/N ratios, no significant differences were observed in speech intelligibility using HPDs (p >0.05). However, at S/N ratio=0, the speech intelligibility descriptively has been improved by using common earmuffs up to 9.07 %. There was a significant difference up to 21.27% in speech intelligibility for proposed molded earplugs at S/N ratio=0 (p <0.05). Increase the HPDs' noise attenuation values lead to increase interference in the speech (p <0.05). The HPDs with the minimum required noise attenuation while maintaining acceptable speech ineligibility should be worn by employees exposed to medium noise levels.


2020 ◽  
Author(s):  
Mina Karami ◽  
Mohsen Aliabadi ◽  
Rostam Golmohammadi ◽  
Morteza Hamidi Nahrani

Abstract Objective This study aimed to investigate the effect of hearing protection devices (HPDs) on speech intelligibility in Persian work environments. Three current earmuffs and three earplugs and one of the prototype of molded earplug were tested on 15 male subjects which were randomly selected. The noise reduction of HPDs was measured based on the Real Ear attenuation at Threshold (REAT) method. Speech intelligibilities during using HPDs were determined based on the speech discrimination score (SDS). Data were analyzed using SPSS, version 22. Results The actual to nominal noise reduction rating values were from 47–84% for HPDs. The earmuffs show higher ratios of actual to nominal noise reduction compared with the earplugs. At two signal to noise ratios, no significant differences were observed in in speech intelligibility using HPDs (p > 0.05). However, at S/N = 0, the speech intelligibility descriptively has been improved by using common earmuffs up to 9.07%. There was a significant difference up to 21.27% in speech intelligibility for proposed molded earplugs at S/N = 0(p < 0.05). It is concluded that, if the trend of signal to noise ratio is positive, the HPDs will reduce the ability to understand speech.


2020 ◽  
Author(s):  
Mina Karami ◽  
Mohsen Aliabadi ◽  
Rostam Golmohammadi ◽  
Morteza Hamidi Nahrani

Abstract Objective: This study aimed to investigate the effect of hearing protection devices (HPDs) on speech intelligibility in Persian work environments. Three current earmuffs and three earplugs and one of the prototypes of molded earplug were tested on 15 male subjects which were randomly selected. The noise reduction of HPDs was measured based on the Real Ear Attenuation at Threshold (REAT) method. Speech intelligibility during using HPDs was determined based on the speech discrimination score (SDS) at two signal to noise (S/N) ratios (0 and +5). Data were analyzed using SPSS, version 22.Results: The actual to nominal noise reduction rating values were from 47% to 84% for HPDs. The earmuffs showed higher ratios of actual to nominal noise reduction compared with the earplugs. At two S/N ratios, no significant differences were observed in speech intelligibility using HPDs (p >0.05). However, at S/N ratio=0, the speech intelligibility descriptively has been improved by using common earmuffs up to 9.07 %. There was a significant difference up to 21.27% in speech intelligibility for proposed molded earplugs at S/N ratio=0(p <0.05). It is concluded that, if the trend of signal to noise ratio is positive, the HPDs will reduce the ability to understand speech.


2015 ◽  
Vol 8 (1) ◽  
pp. 180 ◽  
Author(s):  
Saeid Ahmadi ◽  
Parvin Nassiri ◽  
Ismaeil Ghasemi ◽  
Mohammad R. Monazzam Ep

INTRODUCTION: Hearing protection devices are one of the primary noise reduction tools in developing countries. This study is intended to produce and apply acrylonitrile butadiene styrene (ABS)/clay nanocomposites to fabricate a laboratory single cup earmuffs and then compare it with double cup and single cup pure ABS earmuffs in terms of noise attenuation performance and comfort. In addition, the noise attenuation performance of single cup pure ABS earmuffs is compared with double cup pure ABS earmuffs. METHODS: ABS/nanoclay filament was fabricated using a twin screw extruder. A three dimensional (3D) printing machine and a 3D model of earcup, designed by solid work software, were applied to print single and double cup earmuffs using ABS/nanoclay composite and pure ABS filaments. Finally, using an acoustic test fixture, objective noise attenuation test was performed on three different types of earmuffs, including with and without nano material and a secondary cup. Moreover, earmuffs weight was measured as a comfort component. RESULTS: Insertion loss and calculated noise reduction rating (NRR) of single cup ABS/nanoclay earmuffs (NRR=19.4 dB) and double cup pure ABS earmuffs (NRR=18.93 dB) were improved in comparison with single cup pure ABS earmuffs (NRR=15.7 dB). Additionally, both single cup earmuffs were significantly lighter than double cup earmuffs. Although single cup nano and double cup earmuffs had nearly the same attenuation performance, single cup nano earmuffs were 74 gr lighter than double cup earmuffs, so with reference to comfort, single cup nano earmuffs will probably be more acceptable. CONCLUSIONS: From this survey it might be concluded that, even though single cup ABS/nanoclay earmuffs was lighter than double cup pure ABS earmuffs, it had approximately more attenuation performance in comparison with double cup pure ABS earmuffs. Consequently, users are probably more prone to wear light- weight single cup ABS/nanoclay earmuffs as a result of improved comfort. In short, ABS/nanoclay composite can be considered a good choice in products with the necessity of high acoustic performance and low weight.CallSend SMSAdd to SkypeYou'll need Skype CreditFree via Skype


2019 ◽  
Vol 128 ◽  
pp. 08005
Author(s):  
Guido Alfaro Degan ◽  
Gianluca Coltrinari ◽  
Dario Lippiello ◽  
Pietro Nataletti ◽  
Diego Annesi

The work operations in the quarry activities are the source of many physical agents such as dust and vibrations but especially noise. This last can have relevant negative effects they cause serious problems for the worker’s health. In order to prevent the hearing loss, the employer must provide to the workers the HPD (Hearing Protection Devices). They are inserted inside the ear following a specific procedure to ensure the maximum protection by the noise. For this reason, the use training represents an essential aspect. Also the material, which the device is made of, can influence strongly the actual noise attenuation. The study is based on tests with different HPD, some made of polyurethane and others by silicone. Two experimental campaigns were carried out under different conditions with the same measurement methodology. The results highlight the importance of the methodology used in the test and the relevant role of the use training.


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