Further details of HearCom proposals on optimal procedures for Germany

Loudness scaling

ACALOS: Adaptive CAtegorical LOudness Scaling - Measurement Procedure determining the individual loudness growth function by adaptively estimating and adapting the individual dynamic range. Individually fitted model functions are used to describe the individual loudness curves (Brand, T. and Hohmann, V. 2001. Effect of Hearing Loss, Center Frequency and Bandwidth on the Shape of Loudness Functions in Categorical Loudness Scaling. Audiology. No 40 (2), p. 92-103 ; Brand, T. and Hohmann, V. 2002. An adaptive procedure for categorical loudness scaling. J. Acoust. Soc. Am. No 112 (4), p. 1597-1604)

Questionnaires:

General hearing problems : Rating of hearing problems in 12 given situations (hearing in quiet, in noise, directional hearing) with the revised Oldenburg Inventory ("Oldenburger Inventar R")

Individual hearing problems : First the hearing aid user has to describe five individual situations where hearing and understanding is especially important for him. Then he rates his hearing problems in these situations with the Individual Oldenburg Inventory ("Oldenburger Inventar I")

Hearing aid evaluation: The German questionnaire "Hörgeräte-Bewertung", published by Hörtech GmbH, with 17 questions regarding usage, adaptation, effort of listening, handling, wearing comfort, design, speech intelligibility, sound, own voice, loudness, wind sounds, feedback, telephone and overall satisfaction should be used.

Speech tests:

Freiburg numbers and monosyllabic words: Word lists with either 10 double-digit numbers or 20 monosyllabic words each. (Hahlbrock, K. 1953: Über die Sprachaudiometrie und neue Wörterteste. Archiv Ohren-, Nasen- und Kehlkopfheilkunde. No 162, p. 394-431)

Göttingen sentence test: Sentence lists with meaningful sentences (Kollmeier, B. and Wesselkamp, M. 1997: Development and evaluation of a German sentence test for objective and subjective speech intelligibility assessment. J. Acoust. Soc. Am. No 102 (4), p. 2412-2421)

Oldenburg sentence test: Sentence lists with syntactically fixed but semantically unpredictable sentences (Wagener, K., Brand, T., Kühnel, V. and Kollmeier, B. 1999. Entwicklung und Evaluation eines Satztests für die deutsche Sprache I-III: Design, Optimierung und Evaluation des Oldenburger Satztests. Zeitschrift für Audiologie. No 38 (1-3), p. 4-15, 44-56, 86-95)

Adaptive Procedure to determine SRT in noise: adaptive procedure with decreasing step size converging to 50% intelligibility within 20 sentences (Brand, T. and Kollmeier, B.. 2002. Efficient adaptive procedures for threshold and concurrent slope estimates for psychophysics and speech intelligibility tests. J. Acoust. Soc. Am. No 111 (6), p. 2801-2810)

Benefit verification of monaural or binaural hearing aid provision:

  • Göttingen or Oldenburg sentence test, adaptive SRT, noise presentation level 65 to 75 dB SPL depending on hearing loss, same noise level for all measurements
  • Stationary speech shaped noise.
  • Benefit must exceed twice the intra-individual standard deviation of the test to be significant.
  • Monaural fitting: Measurements 1 and 2 (see below)
    If result of aided measurement 2 is significantly better than unaided measurement 1, finished.
    If result of aided measurement 2 is worse than unaided measurement 1, refitting.
  • Binaural fitting: Measurements 1-3, if necessary, measurements 4-5 (see below)

 

Example benefit of binaural fitting versus monaural fitting left ear (diagrams see above):

  1. S0N90 unaided
  2. S0N90 monaurally aided (left side), right side unaided
  3. S0N90 bilaterally aided
    If result of 3. better than 2., finished (= benefit in all situations)
    If result of 3. worse than 2., additional measurements:
  4. S0N-90 monaurally aided (left side), right side unaided
  5. S0N-90 bilaterally aided
    If result of 5. better than 4. = benefit in some situations
    If result of 5. worse than 4., refitting or only one hearing device due to the speech tests

 

Read on: Rehabilitation pathway in the Netherlands or UK or proceed to Good Practice Procedures