BINAURAL AND BILATERAL CONSIDERATIONS IN HEARING AID FITTING

15.1 BINAURAL EFFECTS IN LOCALIZATION

15.1.1 Localization cues in normal hearing
15.1.2 Effects of hearing loss on localization

15.2 BINAURAL EFFECTS IN DETECTION AND RECOGNITION

15.2.1 Head diffraction effects
15.2.2 Binaural squelch in noise
15.2.3 Binaural redundancy
15.2.4 Binaural loudness summation

15.3 ADVANTAGES OF BILATERAL FITTINGS

15.3.1 Speech intelligibility
15.3.2 Localization
15.3.3 Sound quality
15.3.4 Avoiding late-onset auditory deprivation.
15.3.5 Suppression of tinnitus
15.3.6 Miscellaneous advantages

15.4 DISADVANTAGES OF BILATERAL FITTINGS

15.4.1 Cost
15.4.2 Binaural interference
15.4.3 Self-image
15.4.4 Miscellaneous disadvantages

15.5 TESTS OF BILATERAL ADVANTAGE

15.5.1 Bias in choosing the reference ear for the unilateral condition
15.5.2 The sensitivity of speech tests for assessing bilateral advantage
15.5.3 Role for speech tests in assessing bilateral advantage
15.5.4 Localization tests

15.6 FITTING ASYMMETRICAL HEARING LOSSES

15.6.1 Bilateral versus unilateral fittings for asymmetrical losses
15.6.2 Better ear versus poorer ear for unilateral fittings
15.6.3 Alternatives: FM and CROS

15.7 DECIDING ON BILATERAL VERSUS UNILATERAL FITTINGS

15.8 EFFECT OF BILATERAL VERSUS UNILATERAL FITTING ON ELECTROACOUSTIC PRESCRIPTIONS

15.9 CONCLUDING COMMENTS