Conflicts and tone of voice - as promised
So, HOW do we say things? Quietly, assertively, demandingly, flippantly, ironically, quickly, slowly, overly patiently to the point of sounding condescending, excitedly, gloomily… and in 1001 various other ways. A happy “Hello!” can create a good mood, just like an angry “Fine!” can damage a relationship by leaving things unsaid.

REGISTER - falcetto vs throaty, the latter building more trust;
TIMBER - warm&rich or cold - which one is more appealing, Lucius Malfoy or Ella Fitzgerald?
PROSODY - monotone vs modulation - but everything in moderation, since ending all sentences with a question can be funny until it gets annoying;
PACE - quick vs slow - don’t forget that silence is a pace tool as well;
PITCH - high vs low - lower tones are more calming and more trustworthy;
VOLUME - loud vs hushed - depends which one you need, e.g. Dumbledore raising his volume commands authority while I’ve known a boss of mine achieve the same by almost whispering at a meeting of 20 people;
Tone or HOW we say things builds trust, it is used to influence and persuade AND also helps you avoid conflicts. Throaty, low, warm and modulating voices come across better. Matching your speed to that of your conversation partner creates rapport. And yes, there are voice coaches and yes, you can learn to modulate your voice to sound different, to sound more credible.
Even companies have been branded by shaping the way they sound: https://www.distilled.net/tone-of-voice/
So, next time someone gets upset with you, instead of reacting, try the opposite - calm down and adjust your tone in addition to explaining what you meant behind what you just said that created the confrontation. This is true in negotiations as well as domestic interactions. 7% of our attention goes to content, the rest is appearance and tone. In fact, the same is true with adults as with children and dogs - talk to them gently, since they hear more HOW you say than WHAT you say.
See Julian Treasure’s soundbitey talk here: http://www.ted.com/talks/julian_treasure_how_to_speak_so_that_people_want_to_listen?utm_content=awesm-publisher&utm_source=l.facebook.com&utm_campaign=&utm_medium=on.ted.com-facebook-share&awesm=on.ted.com_rwir).
As for the remaining 10% of conflicts - these are due to differences in opinion - these are usually a result of failures to listen and understand each others’ needs, wants and requirements. As well as sometimes failures to voice these needs, wants and requirements or helping people understand where you are coming from. We mostly explain what we expected AFTER something has not happened the way we wanted. Well, sometimes you an correct course and resume the (business/employment/private) relationship with a little bit better understanding of what everyone expects. Sometimes, the difference in opinion is actually a difference in values and if there is a chasm, then you realise that these type of misunderstandings are likely to happen again and sometimes ending the (business/employment/private) relationship is a more intelligent choice.
If our tone is the mother of all mishaps, then our hearing is surely the father.