A drinking glass can help you like a sound booster. If someone is a deep sleeper and have problems to waking up in the morning with phone alarm, it can be boost by a drinking glass. Redditor tribalwombat discovered that a drinking glass can boost volume from a small device. It’s because the sound will reverberate inside that empty space. This technique is not the best technique for boost sounds like music or alarm, but it is very easy to amplify sound louder.
For alarm it is very useful trick. On top of that, the sleeper has to wake up and pull the phone up to stop it. This may be a little bit harder to stop the alarm, because it needs to wake up first.
Paraphrased by: Sakib Jubab