Question: Several months ago, I was in a session playing as a bard wanting to distract some bugbears while he snuck past. Understanding the goblinoid tongue, I heard one of them state he was starving. I used the phantasmal force spell on one of the bug bears, lets call him BugA. The desired effect was he would see one of the other bugbears as a pile of delicious food(BugB).

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> The phantasm includes sound, temperature, and other stimuli, also evident only to the creature.
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BugA began to eat BugB, who of course, was not pleased about this and attempted to protect himself, mainly by attempting to hold BugA back and producing a **lot of noise**.
Does the phantasmal force spell make BugA unable to hear BugB's shouting and requests for BugA to stop? (considering BugB is effectively obscured by the illusion) 

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> For example. a target attempting to walk across a phantasmal bridge that spans a chasm falls once it steps onto the bridge. If the target survives the fall, it still believes that the bridge exists and comes up with some other explanation for its fall-it was pushed, it slipped, or a strong wind might have knocked it off.
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Unlike the bridge example of the Player Handbook, the illusion covers a character that would be shouting and defending against the actions of the target of the spell. Would BugA continue to make excuses or ignore the noise produced by BugB? 

To put it another way, if a source of noise is inside of an illusion of a box, produced by the spell phantasmal force, can it be heard by the individual who can see the illusion?

Answer: 
There are problems with this use.
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First, Phantasmal Force only *creates* illusory objects, not *replaces* real objects. You could have a pile of delicious food seemingly surround BugB, but if the BugB steps out of Phantasm's area of effect, he stops being affected at all by the obscuring effect of the illusion - BugA would likely rationalise it by having BugB emerge from beneath the hams and cabbages. 

Second, it is for your GM to adjudicate whether you could control the phantasm so finely as to make it follow BugB. The wording is silent on movable phantasms, such as creatures, going out of it's initial zone and refers to phantasm's position. It is arguable whether the phantasm is essentially immobile or can be moved, but make note that spells with movable areas of effect usually mention that the caster can use their bonus action to reposition the effect and make it deal damage. Phantasm is unique in a way that it deals automatic psychic damage as long as target is within or 5 feet away from the phantasm with no action required. 

Judging from the fact that it's a 2nd level spell I would rule it's confined to the initial area. A mobile illusion spell, 3rd level Major Image is completely harmless, while the first damaging illusion that targets a creature instead is Phantasmal Killer at level 4. I think it would be pretty overpowered if you could move your illusion outside of the initial casting area.
The victim will see a pile of food . . . and another bugbear. You are attempting to use give the spell a level of independent action that is well beyond the intent and capability of the spell.

Although you are allowed to create a phantasm that moves, you are not allowed to create a phantasm that reacts intelligently and independently to thwart a second character. There must be some sort of roll to determine the condition of the second bugbear - an attack roll or opposed skill check - which is a clue that you are stretching the spell beyond its intent. In a sense, you are targeting two characters with a single action.

Such a broad definition of the spell opens it to incredible abuse. In any combat, an illusionist could cause any combatant to view any ally as an enemy or an enemy as an ally - a far more powerful effect than anything suggested in the spell description. Against a small party, it becomes almost a save-or-TPK.

By the way . . . what sort of food is the approximate size of a bugbear and appears spontaneously in a bugbear camp? How would a bugbear actually 'attack' such food? And what would he think when the food shifted position - assuming that BugB wasn't actually nailed to that spot on the floor?