rss
Arch Dis Child Fetal Neonatal Ed 2003;88:F315-F318 doi:10.1136/fn.88.4.F315
  • Original article

Noise levels within the ear and post-nasal space in neonates in intensive care

  1. S S Surenthiran1,
  2. K Wilbraham2,
  3. J May3,
  4. T Chant3,
  5. A J B Emmerson3,
  6. V E Newton2
  1. 1Department of Audiological Medicine and Neuro-otology, Medway Maritime Hospital, Kent, UK
  2. 2Centre for Human Communication and Deafness, University of Manchester, Manchester, UK
  3. 3Neonatal Intensive Care Unit, St Marys’ Hospital for Women and Children, Manchester, UK
  1. Correspondence to:
    Dr Surenthiran, Department of Audiological Medicine and Neuro-otology, Medway Maritime Hospital, Windmill Road, Gillingham, Kent ME7 5NY, UK
  • Accepted 13 August 2002

Abstract

Background: Noise exposure in neonatal units has long been suspected of being a cause of hearing loss associated with such units. The noise intensity to which the neonate is exposed varies with the type of ventilatory support used. Also, the post-nasal space is an enclosed cavity that is close to the inner ear and an area of turbulent and hence potentially noisy airflow.

Aim: To determine noise intensities within the ear and post-nasal space in neonates on different modes of ventilatory support using probe microphones, measures previously not undertaken.

Methods: A portable instrument with a probe microphone was used for the measurements. Three groups of infants were included: (a) those receiving no respiratory support (NS); (b) those receiving conventional ventilation (CV); (c) those receiving continuous positive airways pressure (CPAP) support.

Results: The mean in-the-ear noise intensities (at 1 kHz) were 41.7 dB SPL (NS), 39.5 dB SPL (CV), and 55.1 dB SPL (CPAP). The noise intensities in the post-nasal space in those receiving CPAP support were higher than in the other groups, reached mean levels of up to 102 dB SPL at some frequencies, and increased with increasing flow rates.

Conclusions: The most important finding is the high noise intensities in the post-nasal space of those receiving CPAP support. Given the proximity of the post-nasal space to the inner ear, enough noise could be transmitted, especially in infants receiving the higher flow rates, to cause cochlear damage and hence hearing loss. It would therefore be wise, wherever possible, to avoid using the higher flow rates.

Footnotes

    Responses to this article

    • Noise levels in NICU
      • Girish Gupta,
      • T Kinley, MNG Nair
      Arch Dis Child - Fetal Neonatal Ed published online October 6, 2003

    This Article

    1. Abstract
    2. Full text
    3. PDF

    Register for free content


    Free trial
    Individuals may register for a free 60 day online trial to all content.

    Free archive
    The full back archive is now available for all BMJ Journals. Institutional subscribers may access the entire archive as part of their subscription. Personal subscribers will also have access to all content when logged in. Non-subscribers who register have free access to all articles published before 2006 right back to volume 1 issue 1. Register here to access the free archive of all BMJ Journals.

    Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.