N,N-Diisopropyltryptamine (DiPT) is a frequency-selective pitch-distorting psychedelic drug that induces a downward shift in perception where the auditory world of the subject sounds lower in pitch than in a sober state of consciousness. Hurst and Bajo propose the neural mechanisms for this effect and its use as potential therapeutic for tinnitus.
Hurst et al. (Thu,) studied this question.