[AUDITORY] JND values for tactile and audio amplitude signal decrease

[Alfonso Balandra <ponchobalandra@xxxxxxxxx>]

Hello 

My name is Alfonso. I am a post-doc researcher in VR. Currently, I am 
studying the perception of audio-tactile envelope asynchronous perception.

For this research, it is important for me to know the audio and tactile just noticeable difference (JND)
for amplitude decrease (volume drop). After weeks of survey, I cannot find any paper talking
about the perception of volume decrease, for audio OR haptics.

The most related research I could find are several studies on the audio and tactile gap discrimination,
oriented to measure our perception resolution :

-Auditory and tactile gap discrimination:
https://www.researchgate.net/publication/263033589_Auditory_and_tactile_gap_discrimination_by_observers_with_normal_and_impaired_hearing

- Temporal gap detection in tactile channels:
https://www.researchgate.net/publication/8959103_Temporal_gap_detection_in_tactile_channels

Why there aren't any studies that measure the amplitude decrease JNDs ?
Or the equal-loudness countours for audio and haptics can be used to infer the amplitude decrease JNDs ?

- Equal loudness audio contours:
https://www.researchgate.net/publication/8337524_Equal-loudness-level_contours_for_pure_tones
- Sensation magnitude of vibrotactile stimuli: 
https://www.researchgate.net/publication/227207463_Sensation_magnitude_of_vibrotactile_stimuli

Thanks in advance 

Alfonso Balandra
Tokyo Institute of Technology