1. acoustic meatus either of the passages in the outer ear from the auricle to the tympanic membrane
  2. acoustic modem a modem that converts electrical signals to telephone tones and back again
  3. agnostic a person who claims the existence of God is unknowable
  4. acoustic impedance opposition to the flow of sound through a surface
  5. acoustic guitar sound is not amplified by electrical means
  6. acoustics the study of the physical properties of sound
  7. acoustic device a device for amplifying or transmitting sound
  8. acoustic aphasia an impairment in understanding spoken language that is not attributable to hearing loss
  9. ecstatic feeling great rapture or delight
  10. Auguste Comte French philosopher remembered as the founder of positivism
  11. accustomed commonly used or practiced; usual
  12. acoustic reactance opposition to the flow of sound through a surface
  13. astigmatism impaired eyesight common in nearsighted people
  14. astigmatic of or relating to a defect in the eye or in a lens caused by a deviation from spherical curvature which prevents light rays from meeting at a common focus and so results in distorted images
  15. anastigmatic not astigmatic
  16. elastic modulus (physics) the ratio of the applied stress to the change in shape of an elastic body
  17. acoustic nerve a composite sensory nerve supplying the hair cells of the vestibular organ and the hair cells of the cochlea
  18. acoustically with respect to acoustics
  19. anastigmat compound lens or lens system designed to be free of astigmatism and able to form approximately point images
  20. acoustical of or relating to the science of acoustics