Acta Oto-Laryngologica
ISSN: 0001-6489 (Print) 1651-2251 (Online) Journal homepage: http://www.tandfonline.com/loi/ioto20
Comparison of the Hearing Threshold Measured by Pure-Tone Audiometry and by Békésy Sweep Audiometry B. Erlandsson, H. Håkanson, A. Ivarsson & P. Nilsson To cite this article: B. Erlandsson, H. Håkanson, A. Ivarsson & P. Nilsson (1978) Comparison of the Hearing Threshold Measured by Pure-Tone Audiometry and by Békésy Sweep Audiometry, Acta Oto-Laryngologica, 86:sup360, 54-55, DOI: 10.3109/00016487809123471 To link to this article: http://dx.doi.org/10.3109/00016487809123471
Published online: 08 Jul 2009.
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Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=ioto20 Download by: [McMaster University]
Date: 22 May 2016, At: 05:42
Acta Otolaryngol, Suppl. 360: 54-55, 1979
COMPARISON OF T H E HEARING THRESHOLD MEASURED BY PURE-TONE AUDIOMETRY AND BY BEKESY SWEEP AUDIOMETRY B. Erlandsson,' H. H%kanson,2A. Ivarsson' and P. Nilsson' F r o m the 'Drptirtmrni of Physics. U n i ~ ~ e r s iof t y Liind, and the LDrpcrrtrneni Uni\vrsity of Lirnd, Mdrnii Genercil Hospitcil, Mriltnii. Swvden
o f Otlaryngology.
Downloaded by [McMaster University] at 05:42 22 May 2016
Ahstrrrct. The hearing thresholds of 1 IS subjects. workers
in a shipyard. were determined both by Bekesy sweep audiometry and by conventional individual pure-tone audiometry at fixed audiometric frequencies. The Bekesy method gave the lowest values for the hearing thresholds. It has been possible to find a useful linear relation between pure-tone and Bekesy hearing thresholds. With the help of a retest experiment it has been established that the standard deviations of hearing thresholds. obtained under similar conditions in a pure-tone investigation, are about twice as large a s those obtained in a Bekesy investigation.
In an impulse-noise project at Kockums Shipyard where we try to measure occupational hearing loss, the principal purpose is to discover significant changes in the hearing threshold as a function of noise exposure time (Erlandsson et al., 1978). It is therefore important to know how large the variations in the hearing threshold measurements are. This paper gives the results of t h e reproducibility and of the relation between hearing thresholds obtained with manual pure-tone and self-recording Bekesy sweep audiometry for subjects with varying degrees of hearing impairment. MATERIAL AND METHODS The hearing threshold of 115 subjects, aged 25 to 63 years, from Kockums Shipyard were determined by both Bekesy sweep audiometry and pure-tone audiometry at fixed audiometric frequencies after 16 h rest from excessive occupational noise. A Bekesy audiometer type Demlar 120 and a sound insulated box were in-
stalled in a standard caravan. The attenuation rate was 2.5 dB/s with pulsed tone-presentation and the sweep time from 250 to 10 kHz was 400 s. The pure-tone audiometry was performed by the same audiometrist in 5 dBsteps. RESULTS Comparison between hearing thresholds obtained with pure-tone and BPkPsysweep audiometry The hearing thresholds has been determined for 230 ears. The regression equation for Bekesy threshold (HL,) on pure tone thresholds (HL,) for the audiometric frequencies 1-6 kHz is: HL,= -3.4+0.93 HLT and for pure-tone on Bekesy is HL,,=8.0+0.96x HL,. Test reliability of BPkPsy-sweep audiograms In this investigation 10 subjects were measured five times with an interval of at least 24 h. The pooled estimate of the variance was computed by first obtaining the variance for each ear and then the mean value for all 20 ears was calculated. The standard deviations have their lowest values for 1 kHz, increasing slowly towards lower and higher frequencies. Reproducibility in BPkPsy and pure tone audiometry According to Madansky (1959) it is possible to estimate the standard deviation of the puretone threshold values if we know the standard
Ptrrr-tot1e
deviation of the Bekesy threshold values and the regression equation for pure-tone on Bekesy threshold at the different audiometric frequencies. Standard deviation (dB) Bekesy Pure-tone
Frequency ( k H z ) 0.51 1.52 3 4 6 8 3.2 2.4 2.8 3.5 2.8 3.3 3.4 4.2 6.3 6.2 6.5 4.7 6.6 5.3 7.3 10.4
Downloaded by [McMaster University] at 05:42 22 May 2016
DISCUSSION The hearing threshold is not a very well-defined dividing-line between hearing and not hearing. This uncertainty is illustrated by the swinging in the curve of the Bekesy audiometer, where it also is possible to determine the ability of the subject to state the threshold. In pure-tone audiometry and particularly where the steps are 5 dB and where the threshold is defined as the reading where the subject marks 2 out of 3 bursts, the uncertainty is great. The result shows that there is a significant difference between thresholds measured by Bekesy and by pure-tone audiometry, which is in good agreement with results obtained in other investigations (Burns & Hinchcliffe, 1957; Harris, 1964; Delany et al.. 1966; Knight, 1966).
CONCLUSIONS The comparison between t h e two types of audiometry shows that in all cases Bekesy audiometry gives a lower and more reliable hearing threshold.
REFERENCES Erlandsson. B., H%kanson. H., Ivarsson, A , , Milstam, H . , Nilsson, P. & Salen. B. 1978. lmpulsbullrets horselskadliga effekt. Si~cri.sk Otolnpngologisk Fiircwinx, vol. 2 , no. 1. Burns, W . & Hinchcliffe. R. 1957. Comparison of the auditory threshold as measured by individual pure tone and by Bekesy audiometry. JAcorlsf Soc Am 29, 1274. Delany, M. E., Whittle, L. S. & K n o x , E . C. 1966. A note on the use of self-recording audiometry with children. J Lrrryngol OrolRU, 1135. Harris, H . D. 1964. Bekesy audiometry at 20 frequencies from 0.2 to 6 Kclsec. J Acortsf Soc A m 37, 1954. Knight, J. J . 1966. Normal hearing threshold determined hy manual and self-recording techniques. J Acorrst SOL. A m 3 9 , 1966. Madansky, A. 1959. The fitting of straight lines when both variables are sub.ject to error. J A m Stor A s s 54, 177.
ISSN: 0001-6489 (Print) 1651-2251 (Online) Journal homepage: http://www.tandfonline.com/loi/ioto20
Comparison of the Hearing Threshold Measured by Pure-Tone Audiometry and by Békésy Sweep Audiometry B. Erlandsson, H. Håkanson, A. Ivarsson & P. Nilsson To cite this article: B. Erlandsson, H. Håkanson, A. Ivarsson & P. Nilsson (1978) Comparison of the Hearing Threshold Measured by Pure-Tone Audiometry and by Békésy Sweep Audiometry, Acta Oto-Laryngologica, 86:sup360, 54-55, DOI: 10.3109/00016487809123471 To link to this article: http://dx.doi.org/10.3109/00016487809123471
Published online: 08 Jul 2009.
Submit your article to this journal
Article views: 13
View related articles
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=ioto20 Download by: [McMaster University]
Date: 22 May 2016, At: 05:42
Acta Otolaryngol, Suppl. 360: 54-55, 1979
COMPARISON OF T H E HEARING THRESHOLD MEASURED BY PURE-TONE AUDIOMETRY AND BY BEKESY SWEEP AUDIOMETRY B. Erlandsson,' H. H%kanson,2A. Ivarsson' and P. Nilsson' F r o m the 'Drptirtmrni of Physics. U n i ~ ~ e r s iof t y Liind, and the LDrpcrrtrneni Uni\vrsity of Lirnd, Mdrnii Genercil Hospitcil, Mriltnii. Swvden
o f Otlaryngology.
Downloaded by [McMaster University] at 05:42 22 May 2016
Ahstrrrct. The hearing thresholds of 1 IS subjects. workers
in a shipyard. were determined both by Bekesy sweep audiometry and by conventional individual pure-tone audiometry at fixed audiometric frequencies. The Bekesy method gave the lowest values for the hearing thresholds. It has been possible to find a useful linear relation between pure-tone and Bekesy hearing thresholds. With the help of a retest experiment it has been established that the standard deviations of hearing thresholds. obtained under similar conditions in a pure-tone investigation, are about twice as large a s those obtained in a Bekesy investigation.
In an impulse-noise project at Kockums Shipyard where we try to measure occupational hearing loss, the principal purpose is to discover significant changes in the hearing threshold as a function of noise exposure time (Erlandsson et al., 1978). It is therefore important to know how large the variations in the hearing threshold measurements are. This paper gives the results of t h e reproducibility and of the relation between hearing thresholds obtained with manual pure-tone and self-recording Bekesy sweep audiometry for subjects with varying degrees of hearing impairment. MATERIAL AND METHODS The hearing threshold of 115 subjects, aged 25 to 63 years, from Kockums Shipyard were determined by both Bekesy sweep audiometry and pure-tone audiometry at fixed audiometric frequencies after 16 h rest from excessive occupational noise. A Bekesy audiometer type Demlar 120 and a sound insulated box were in-
stalled in a standard caravan. The attenuation rate was 2.5 dB/s with pulsed tone-presentation and the sweep time from 250 to 10 kHz was 400 s. The pure-tone audiometry was performed by the same audiometrist in 5 dBsteps. RESULTS Comparison between hearing thresholds obtained with pure-tone and BPkPsysweep audiometry The hearing thresholds has been determined for 230 ears. The regression equation for Bekesy threshold (HL,) on pure tone thresholds (HL,) for the audiometric frequencies 1-6 kHz is: HL,= -3.4+0.93 HLT and for pure-tone on Bekesy is HL,,=8.0+0.96x HL,. Test reliability of BPkPsy-sweep audiograms In this investigation 10 subjects were measured five times with an interval of at least 24 h. The pooled estimate of the variance was computed by first obtaining the variance for each ear and then the mean value for all 20 ears was calculated. The standard deviations have their lowest values for 1 kHz, increasing slowly towards lower and higher frequencies. Reproducibility in BPkPsy and pure tone audiometry According to Madansky (1959) it is possible to estimate the standard deviation of the puretone threshold values if we know the standard
Ptrrr-tot1e
deviation of the Bekesy threshold values and the regression equation for pure-tone on Bekesy threshold at the different audiometric frequencies. Standard deviation (dB) Bekesy Pure-tone
Frequency ( k H z ) 0.51 1.52 3 4 6 8 3.2 2.4 2.8 3.5 2.8 3.3 3.4 4.2 6.3 6.2 6.5 4.7 6.6 5.3 7.3 10.4
Downloaded by [McMaster University] at 05:42 22 May 2016
DISCUSSION The hearing threshold is not a very well-defined dividing-line between hearing and not hearing. This uncertainty is illustrated by the swinging in the curve of the Bekesy audiometer, where it also is possible to determine the ability of the subject to state the threshold. In pure-tone audiometry and particularly where the steps are 5 dB and where the threshold is defined as the reading where the subject marks 2 out of 3 bursts, the uncertainty is great. The result shows that there is a significant difference between thresholds measured by Bekesy and by pure-tone audiometry, which is in good agreement with results obtained in other investigations (Burns & Hinchcliffe, 1957; Harris, 1964; Delany et al.. 1966; Knight, 1966).
CONCLUSIONS The comparison between t h e two types of audiometry shows that in all cases Bekesy audiometry gives a lower and more reliable hearing threshold.
REFERENCES Erlandsson. B., H%kanson. H., Ivarsson, A , , Milstam, H . , Nilsson, P. & Salen. B. 1978. lmpulsbullrets horselskadliga effekt. Si~cri.sk Otolnpngologisk Fiircwinx, vol. 2 , no. 1. Burns, W . & Hinchcliffe. R. 1957. Comparison of the auditory threshold as measured by individual pure tone and by Bekesy audiometry. JAcorlsf Soc Am 29, 1274. Delany, M. E., Whittle, L. S. & K n o x , E . C. 1966. A note on the use of self-recording audiometry with children. J Lrrryngol OrolRU, 1135. Harris, H . D. 1964. Bekesy audiometry at 20 frequencies from 0.2 to 6 Kclsec. J Acortsf Soc A m 37, 1954. Knight, J. J . 1966. Normal hearing threshold determined hy manual and self-recording techniques. J Acorrst SOL. A m 3 9 , 1966. Madansky, A. 1959. The fitting of straight lines when both variables are sub.ject to error. J A m Stor A s s 54, 177.
