ascent, assent, accent

Ascent or ascent ( uh sent ) means the act of going up or rising, literally or figuratively--
They watched the ascent of the hot air balloon until it was no longer visible.
The ascent of an airplane makes some people uncomfortable.

Assent or assent ( rhymes with ascent ) means the act of giving permission or agreement--
He gave his assent to the terms and conditions.
I would like to call my lawyer before I give my assent to this.
Assent may be used as a noun ( thing or idea )--
His assent is important to the contract talks.
Assent may be used as a verb ( action word )--
He has to assent to this, or the deal is off.

Accent or accent ( ack sent ) means a hint or note of something, as in home decor--
That vase would make a nice accent in a dull corner.
Accent also means  the stress or emphasis on a word syllable, or the pronunciation of speech--
It is pronounced with the accent on the first syllable.
His slight foreign accent sounded sophisticated to most people.

Now that you know that, you can say--
"His accent made the ascent more difficult, as the crew didn't know whether they had his assent for the new route."

Note--"ascend" is the verb ( action word ) form of "ascent"--
They watched the plane ascend until it flew out of sight.

Note # 2--"assent" and "ascent" rhyme perfectly with "a sent", "a cent", and "a scent"--
He looked for a sent email with her address on it.
He doesn't have a cent.
There was a scent of gardenias in the air.

Note # 3-- "assents" is the third person singular ( he, she, it ) form of  the verb ( action word ) "assent"--
We cannot continue unless he assents.
Not to be confused with "a sense"--
He had a sense of  foreboding.