Related Experiment Video
Updated: May 16, 2026

Systematic Hearing Performance Evaluation Process for Adolescents with Cochlear Implantation at Early Ages
Published on: March 24, 2023
The effect of a carrier phrase on hearing aid amplification of single words in quiet
Niek J Versfeld1, S Theo Goverts
1Department of ENT/Audiology and EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands. n.versfeld@vumc.nl
Objective:
A common method to assess the functional benefit of hearing aids is by measuring the performance-intensity curve of single words in quiet with and without hearing aids. Currently, virtually all hearing aids use signal processing, which may have a marked effect on gain as a function of time. Thus, hearing-aid behavior may be different for a word presented in isolation compared to the same word preceded by a carrier phrase, which is a closer replication of natural conversation. The present research was conducted to assess this difference.
Design:
In a hearing-aid test box, speech materials were routed through hearing aids and the output was recorded with a 2cc coupler.
Study Sample:
Seven different hearing aids were programmed according to the manufacturer's fitting rules, using a given hearing loss.
Results:
Depending on the hearing aid, and the hearing-aid setting, differences in the overall level of the hearing-aid processed words ranged from 1.5 to 3.5 dB. Differences were due to slow attack times in amplitude compression.
Conclusions:
Although differences were small for most hearing aids, the use of a carrier phrase should be considered in speech intelligibility tests to ensure that hearing-aid performance closer reflects that in real life.
Related Concept Videos
Interference: Path Lengths
Two special sources may be considered when they are in phase. This can be easily achieved by feeding the two sources from the same source. An example would be synchronizing the two speakers by feeding them with the same source, such as the sound waves produced by a tuning fork. This setup ensures that the two sources have the same frequency and are...
Hearing
Sound Waves: Interference
Doppler Effect - II
Perceiving Loudness, Pitch, and Location
Place theory, or place coding, suggests that different pitches are heard because various sound waves activate specific locations along the cochlea's basilar membrane. The brain determines the pitch of a sound by identifying...
Echo
Imagine the sound is reflected back to the ears. Assuming that the source is very close to the human, the difference between hearing the two sounds—the emitted sound and the reflected sound—may be more than the minimum time for perceiving distinct sounds. If this is the case, then the...
