Purpose: The objective of the study was to investigate the influence of noise (energetic) and speech (energetic plus informational) maskers on the head shadow (HS), squelch (SQ), and binaural summation (SU) effect in bilateral and bimodal cochlear implant (CI) users. Method: Speech recognition was measured in the presence of either a competing talker or modulated speech-shaped noise in 10 bimodal and 10 bilateral adult CI users. HS, SQ, and SU effects were calculated. The interfering signals were manipulated with respect to F0 to consider the influence of different speaker voices. Results: The effects HS, SQ, and SU differed depending on the type of masker. A detailed analysis of errors was used to dissociate energetic and informational masking effects. The analysis showed a release from energetic than from informational masking. Conclusion: Noise interferers are not sufficient to reflect difficulties experienced with speech understanding in noise for bilateral and bimodal CI users.