For me, there is no difference between the "ths" in deaths and the "ths" in "months".
Interested in Language
I'm sometimes mixed up with how to pronounce the plural form of "death": deaths. In theory, it should sound like [dεθs], but nobody seem to pronounce it in that way (at least to my ears). In addition, it seems to be hard to pronounce s-sound right after θ-sound. On the other hand, the plural form of "month", which also ends with th-sound, is often pronounced like [mʌnts]. I think it's easier to pronounce. In general, when I pronounce the plural form of words with th at the end, how should I pronounce it? Otherwise is there no general rule for it？
If you use /t/, it will sound like debts. You can make an easier version of /θs/ by not sticking the tongue between the teeth, but up against the back of the top teeth so it's a quicker movement.
For me, "deaths" is purely sybyllant, while "months" is slightly voiced.
Thank you for your comment, probus, but what is "sybyllant"?
I think probus means sibilant, which is a hissing sound.
However, I agree with MikeNewYork. Deaths and months have the same 'ths' sound, and the 'th' retains its singular pronunciation in the plural, (with the addition of an 's' of course).
This isn't the case with words such as, mouth /maʊθ/ mouths /maʊðz/ or youth /juːθ/ youths /juːðz/ where in the plural the 'th' is voiced. I don't know any easy rule for this. You need to learn them as you go.
Thank you very much, Roman55.