Amplitude of water pouring sound

The familiar pouring sound we all hear when preparing tea or coffee has been a rare topic of study so far, despite its importance in several applications. We experimentally find that the sound amplitude increases with the jet corrugation, indicating that thin jets are louder than thick ones for the same given height. When pouring from a high distance, the jet breaks up into impacting drops, and the amplitude increases with the jet length and diameter. Results show that the jet corrugation relates to the volume of entrained air, hence the pouring sound can enter as a practical method to measure water aeration rates.