Individuals with auditory neuropathy spectrum disorder (ANSD) or auditory processing disorders (APDs) often suffer from temporal processing deficits leading to degraded speech perception. The situation becomes worse in the presence of background noise. Evidence exists that the exaggeration of speech envelope may enhance intelligibility, although a comprehensive evaluation of envelope enhancement algorithms is lacking. In the present study, two schemes of envelope enhancement algorithms, with and without an additional noise reduction algorithm, were applied to sentence-level-stimuli in different background noise conditions. The algorithms were assessed objectively using the Hearing Aid Speech Perception Index (HASPI). Results showed that the envelope enhancement algorithms are effective in improving the predicted speech intelligibility score under certain Signal-to-Noise Ratio (SNR) conditions.