I see all the time that the recommended ways to mine is to dig deep and listen out for the sounds of monsters in caves.
My niece is deaf, and whilst she loves the building aspect of the game, tasks like "finding caves" or "knowing a monster is behind you" are obviously more difficult.
Are there any settings or mods that can be used to give a visual indication that the player is in the vicinity of mobs? Especially something showing the direction the sound is coming from.
The Captioning API is a modloader mod that captions the sounds of the world. Some of them are deliberately ambiguous, I only learnt through hearing the noises at the same time.
Most of the monster sounds are low pitch. There are chairs that integrate speakers to let players feel low frequency sounds. You should investigate those.
In Minecraft release 1.9+ you can enable subtitles in the corner of the screen, which show what sounds played in the last ~5 seconds! Each sound subtitle fades away with time, darkening and vanishing in a few seconds. Plus, small arrows indicate which side of the player the sound came from.
Or use commands (more reliable, but harder):
To be notified when a specific mob is close, put the command below in a normal command block on a slow Redstone clock:
/execute @e[type=MobName] ~ ~ ~ execute @a[r=R] ~ ~ ~ say @p Warning: MobName
You can change the MobName to detect mobs with that name and adjust the radius (r) to a value that you want. But watch out - the command syntax is case-sensitive! Don't put spaces inside the brackets and don't forget to use capital letters in mob names!
Example: To get warned when a Zombie is less then 5 blocks away from you, use this:
/execute @e[type=Zombie] ~ ~ ~ execute @a[r=5] ~ ~ ~ say @p WARNING: Zombie
Example #2: To be notified when a cave is somewhere around and when it's close, use this bat detector (I used a higher value of r):
/execute @e[type=Bat] ~ ~ ~ execute @a[r=16] ~ ~ ~ say @p Cave 20 blocks away!
/execute @e[type=Bat] ~ ~ ~ execute @a[r=8] ~ ~ ~ say @p Cave 10 blocks away!
You could turn off all music and turn the sound volume up. Lay the speakers on their back, put a thin plate on them and put sand on them. Sound vibrations will cause Chladni Patterns (sorry, the German Wikipedia Article is more informative here...) to occur, similar to the ones you see in this YouTube video:
With some practice, your niece might learn to differ between the patterns of e.g. Zombie grumbling and water flowing.
note: This is still a draft which I plan to expand into more precise instructions
I'd like to elaborate a bit more on my previous comment, which while also dealing with visualization, is about a software solution instead of the hardware solution I also posted.
The basic idea is displaying a spectrogram together with the (windowed) Minecraft so that the audio visualization helps locating mobs, caves etc. So first some background information from Wikipedia:
A spectrogram is a time-varying spectral representation (forming an image) that shows how the spectral density of a signal varies with time. Also known as spectral waterfalls, sonograms, voiceprints, or voicegrams, spectrograms are used to identify phonetic sounds, to analyse the cries of animals; they were also used in many other fields including music, sonar/radar, speech processing, seismology, etc. The instrument that generates a spectrogram is called a spectrograph.
As an example, here's a spectrogram of a violin:
Time flows from left to right while the bottom represents lower frequencies and the top the higher ones. It's actually easier to understand in animation, so here's some classical music
(there's also the infamous Aphex Twin face, see e.g. here. It's actually incredible what stuff one can do with this.)
Since the location of objects requires Stereo sound, you need a software that can plot a real time stereo spectrogram. (Ok, maybe a simple spectral analyser may suffice, but in order to compensate for the difficulty of identifying a signal, looking back in time for a second sounds fair) I'll assume you don't want to buy a commercial product for this, and why should you when there's freeware available?
The simplest one I found is called Spectrogram 5.0. It's a tiny download and provides a stereo view, although the resolution is quite raw IMHO. (I'll update this answer if you have trouble with the configuration).
The OpenSource project Spek looks promising but doesn't seem to support live output at the moment, while the Overtone Analyzer Free Edition looks a lot more elaborated but I haven't found a Stereo visualization setting yet. Other programs I have not yet checked are SFS/RTGRAM, WaveSurfer, Waterfall Spectrum Analyzer.
Finally, there is Spectrum Lab, which I have used quite some time ago. I don't remember if it supports Stereo, but with the correct settings the results are great...
Captions/subtitles have been added in the official Minecraft 1.9 release.
I wonder if a set of speakers/headphones could be placed/tuned so that she could feel the stereo sound? If you attempt this, it may be advantageous to swap out the normal sounds of the game for ones that are (lower?) tones that can be more readily felt. The sound files are in the minecraft folder under resources/sound/sound3/mob.
I honestly, don't know if this would work... It's just the first low-tech thing that came to mind.
Good luck. Don't dig down. ;-)
Use Rei's Minimap mod For Monsters, and X-ray texture pack for finding caves. X-ray can be annoying, but you can switch it off easily on the menu.
I realise this question is quite old, but came across it "by accident" and thought this might help.
When I recently installed my ASUS motherboard drivers on a new system, I got the option of installing a program called "Sonic Radar II".
From the ROG Sonic Radar page:
Sonic Radar is and onscreen overlay that visually represents sound activities according to their positional location. It is designed as a gaming aid for pro/am gamers, those hard of hearing or unable to use in-game audio clearly. It does not interfere with game files, nor does it represent anything more than the game engine produces.
The page also contains a video explaining things in more detail.
I haven't tried this with minecraft specifically (or with any other game, for that matter), because for people with normal hearing, it's arguably a bit of a cheat. But for people with hearing disabilities, it might be just the thing...
