;; (mantissa-mask in bits)

;; Masks off bits in the mantissa of the floating point sample
;; value. This introduces a quantization noise, but is less severe
;; than linearly quantizing the signal.

;; in - input signal
;; bits - the number of mantissa bits to preserve. a number from 0 to 23.

(let ((s (mul (sin-osc ar (mul-add (sin-osc kr 0.2 0) 400 500) 0) 0.4)))
  (audition (out 0 (mantissa-mask s 3))))