The effect of gain mismatch on horizontal localization performance

Data from this study suggest that as long as a sound contains the low-frequency information that allows ITD cues to be accessed, left/right discrimination is not severely affected by an interaural gain mismatch of up to 9 dB. Consequently, for the purpose of improving localization performance, it is more important to preserve the ITD than the IID cues in bilaterally fitted hearing aids. That is, a mismatch of devices that produce different time delays, vent sizes, or microphone modes across ears are more likely to interfere with the ability to localize sounds in the horizontal plane than are gain mismatches caused by non- synchronized compression.