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Comparison of speech intelligibility measures for an electronic amplifying earmuff and an identical passive attenuation device.

Byrne DC, Palmer CV - Audiol Res (2012)

Bottom Line: The purpose of this study was to identify any differences between speech intelligibility measures obtained with MineEars electronic earmuffs (ProEars, Westcliffe, CO, USA) and the Bilsom model 847 (Sperian Hearing Protection, San Diego, CA, USA), which is a conventional passive-attenuation earmuff.These two devices are closely related, since the MineEars device consisted of a Bilsom 847 earmuff with the addition of electronic amplification circuits.Additionally, since an extensive electro-acoustic evaluation of the electronic earmuff was not performed as a part of this study, the exact cause of the reduced intelligibility scores at full volume remains unknown.

View Article: PubMed Central - PubMed

Affiliation: National Institute for Occupational Safety and Health, Cincinnati, OH;

ABSTRACT
The purpose of this study was to identify any differences between speech intelligibility measures obtained with MineEars electronic earmuffs (ProEars, Westcliffe, CO, USA) and the Bilsom model 847 (Sperian Hearing Protection, San Diego, CA, USA), which is a conventional passive-attenuation earmuff. These two devices are closely related, since the MineEars device consisted of a Bilsom 847 earmuff with the addition of electronic amplification circuits. Intelligibility scores were obtained by conducting listening tests with 15 normal-hearing human subject volunteers wearing the earmuffs. The primary research objective was to determine whether speech understanding differs between the passive earmuffs and the electronic earmuffs (with the volume control set at three different positions) in a background of 90 dB(A) continuous noise. As expected, results showed that speech intelligibility increased with higher speech-to-noise ratios; however, the electronic earmuff with the volume control set at full-on performed worse than when it was set to off or the lowest on setting. This finding suggests that the maximum volume control setting for these electronic earmuffs may not provide any benefits in terms of increased speech intelligibility in the background noise condition that was tested. Other volume control settings would need to be evaluated for their ability to produce higher speech intelligibility scores. Additionally, since an extensive electro-acoustic evaluation of the electronic earmuff was not performed as a part of this study, the exact cause of the reduced intelligibility scores at full volume remains unknown.

No MeSH data available.


Related in: MedlinePlus

Measurements of HINT speech-shaped noise in the diffuse-field test chamber [overall level=90 dB(A)].
© Copyright Policy - open-access
Related In: Results  -  Collection


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Figure 2: Measurements of HINT speech-shaped noise in the diffuse-field test chamber [overall level=90 dB(A)].

Mentions: A measurement of the 90 dB(A) noise used in this study taken with a precision measurement microphone system (G.R.A.S. model 40HF) at the head-center location in the diffuse field chamber is shown in Figure 2. A measurement with the acoustical test fixture and the resulting transfer function (i.e. difference between these two measurements) are also shown. The upper curve from Figure 2 is shown again in Figure 3, and the remaining curves in this figure indicate the levels present under each earmuff condition with only the 90 dB(A) speech-shaped background noise being played into the test chamber. The difference between the upper curve and any of the others represents the amount of attenuation provided by that particular earmuff condition.


Comparison of speech intelligibility measures for an electronic amplifying earmuff and an identical passive attenuation device.

Byrne DC, Palmer CV - Audiol Res (2012)

Measurements of HINT speech-shaped noise in the diffuse-field test chamber [overall level=90 dB(A)].
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4630949&req=5

Figure 2: Measurements of HINT speech-shaped noise in the diffuse-field test chamber [overall level=90 dB(A)].
Mentions: A measurement of the 90 dB(A) noise used in this study taken with a precision measurement microphone system (G.R.A.S. model 40HF) at the head-center location in the diffuse field chamber is shown in Figure 2. A measurement with the acoustical test fixture and the resulting transfer function (i.e. difference between these two measurements) are also shown. The upper curve from Figure 2 is shown again in Figure 3, and the remaining curves in this figure indicate the levels present under each earmuff condition with only the 90 dB(A) speech-shaped background noise being played into the test chamber. The difference between the upper curve and any of the others represents the amount of attenuation provided by that particular earmuff condition.

Bottom Line: The purpose of this study was to identify any differences between speech intelligibility measures obtained with MineEars electronic earmuffs (ProEars, Westcliffe, CO, USA) and the Bilsom model 847 (Sperian Hearing Protection, San Diego, CA, USA), which is a conventional passive-attenuation earmuff.These two devices are closely related, since the MineEars device consisted of a Bilsom 847 earmuff with the addition of electronic amplification circuits.Additionally, since an extensive electro-acoustic evaluation of the electronic earmuff was not performed as a part of this study, the exact cause of the reduced intelligibility scores at full volume remains unknown.

View Article: PubMed Central - PubMed

Affiliation: National Institute for Occupational Safety and Health, Cincinnati, OH;

ABSTRACT
The purpose of this study was to identify any differences between speech intelligibility measures obtained with MineEars electronic earmuffs (ProEars, Westcliffe, CO, USA) and the Bilsom model 847 (Sperian Hearing Protection, San Diego, CA, USA), which is a conventional passive-attenuation earmuff. These two devices are closely related, since the MineEars device consisted of a Bilsom 847 earmuff with the addition of electronic amplification circuits. Intelligibility scores were obtained by conducting listening tests with 15 normal-hearing human subject volunteers wearing the earmuffs. The primary research objective was to determine whether speech understanding differs between the passive earmuffs and the electronic earmuffs (with the volume control set at three different positions) in a background of 90 dB(A) continuous noise. As expected, results showed that speech intelligibility increased with higher speech-to-noise ratios; however, the electronic earmuff with the volume control set at full-on performed worse than when it was set to off or the lowest on setting. This finding suggests that the maximum volume control setting for these electronic earmuffs may not provide any benefits in terms of increased speech intelligibility in the background noise condition that was tested. Other volume control settings would need to be evaluated for their ability to produce higher speech intelligibility scores. Additionally, since an extensive electro-acoustic evaluation of the electronic earmuff was not performed as a part of this study, the exact cause of the reduced intelligibility scores at full volume remains unknown.

No MeSH data available.


Related in: MedlinePlus