Most often the early signs of hearing loss show up as a temporary change in one’s hearing threshold. This typically resolves within 16-18 hours and we have all experienced this, especially after a loud concert or a long day at work- typically a feeling of muffled sound and perhaps some ringing in your ears. The app measures the softest sound that can be heard before the music or noise exposure, and then again after the music or noise exposure. This difference is a measure of the temporary hearing loss, also known as temporary threshold shift (or TTS).
A small shift, measured in decibels or dB, is not significant, but larger ones between 6-15 dB (orange), or even greater than 15 dB (red) can be indicators of over-exposure.
If this happens, then a day or two of relative quiet may be very useful, in order to prevent this temporary problem from becoming a permanent one. Hearing protection would be very useful the next time you are in a similar environment.