zibun de kimeru no de ha naku, onseiannai ni sitagau.

The sentence has a very common contrast pattern:

• A のではなく、B
• not A, but B
• or more naturally, rather than A, do B

So here:

• 自分で決める = decide by yourself
• のではなく = rather than / instead of
• 音声案内に従う = follow the voice guidance

So the whole sentence means something like:

• Rather than deciding for yourself, follow the voice guidance.

It contrasts two actions:

1. deciding on your own
2. following the guidance

In 自分で, the で does not mean location here. It marks the idea of by oneself or on one’s own.

So:

• 自分で決める = decide for oneself / decide on one’s own

This is a very common pattern:

• 自分でやる = do it yourself
• 自分で選ぶ = choose for yourself
• 自分で作る = make it yourself

In this sentence, 自分で emphasizes that the person is making the decision independently, without relying on the guidance.

Not necessarily. 自分 often means oneself, and exactly who it refers to depends on context.

It can mean:

• myself
• yourself
• himself / herself
• oneself

In a sentence like this, especially if it sounds instructional, 自分で決める is best understood as:

• decide for yourself
• decide on your own

So here 自分 is more general than specifically myself.

のではなく is a grammar pattern used to reject one option and present another.

Core meaning

• not ... but ...
• rather than ...
• instead of ...

In this sentence:

• 自分で決めるのではなく = rather than deciding by yourself / not deciding by yourself

Then the second half gives the preferred action:

• 音声案内に従う = follow the voice guidance

So together:

• Rather than deciding for yourself, follow the voice guidance.

This pattern is very common in written Japanese and explanations.

The の nominalizes the preceding phrase, turning 自分で決める into something like the act of deciding for yourself.

So structurally:

• 自分で決める = to decide by oneself
• 自分で決めるの = the act of deciding by oneself
• 自分で決めるのではなく = not the act of deciding by oneself, but...

You do not need to translate that の directly every time. It is just part of the grammar that allows the verb phrase to connect smoothly to ではなく.

It is in dictionary form because it is part of a larger grammar structure, not because it means present tense in the usual English sense.

Here:

• 決める is the plain verb form
• it modifies the nominalizer の
• together: 決めるの
• then: 決めるのではなく

This is very normal in Japanese. A plain verb can come before の to create a noun-like phrase.

So this is not unusual at all. It is just the form required by the pattern.

Yes. That would be a more conversational version.

Compare:

• 自分で決めるのではなく = more formal, written, explanatory
• 自分で決めるんじゃなくて = more casual, spoken

Also possible:

• 自分で決めるのではなくて

All of these express roughly the same contrast.

So the version in your sentence sounds a bit more formal or written, which fits things like instructions, manuals, announcements, or formal guidance.

Because 従う takes に, not を.

With 従う, the thing or person you obey/follow is marked by に:

• ルールに従う = follow the rules
• 先生に従う = obey the teacher
• 指示に従う = follow instructions
• 音声案内に従う = follow the voice guidance

So this is a verb-specific particle pattern. It is something you need to learn together with the verb:

• 従う + に

従う means:

• to follow
• to obey
• to act in accordance with

In this sentence, it does not mean physically walking behind something. It means:

• to follow instructions
• to comply with guidance
• to do what the guidance says

So 音声案内に従う means:

• follow the voice guidance
• act according to the audio instructions

This is a fairly formal and common verb in instruction-like contexts.

音声案内 means something like:

• voice guidance
• audio guidance
• spoken instructions
• voice prompts

It is often used for:

• navigation systems
• elevators
• automated systems
• public facilities
• machines or devices

So in this sentence, it probably means an automated spoken guide or set of spoken instructions that the listener should follow.

Yes, most likely. Japanese often leaves the subject unstated when it is clear from context.

Depending on the situation, the implied subject could be:

• you
• the user
• the passenger
• the listener
• one

So the sentence could be understood as:

• You should follow the voice guidance rather than decide for yourself.

Japanese often sounds more natural by leaving that subject out.

It can function like one, even though it does not use a direct imperative form.

The plain form 従う can appear in:

• written instructions
• formal notices
• rule statements
• manuals
• slogans

So it may sound like:

• Follow the voice guidance rather than deciding for yourself.

It is not the blunt imperative 従え, and it is not the polite request 従ってください, but in context it can still feel directive or instructional.

The comma helps separate the two contrasted parts:

• 自分で決めるのではなく、
• 音声案内に従う。

It makes the sentence easier to read and highlights the contrast:

• not this,
• but that

Japanese punctuation is sometimes more flexible than English punctuation, but here the comma is very natural.

Yes, in the sense that it rejects the first option before presenting another one.

The pattern says:

• it’s not that A; rather, B
• instead of A, B
• rather than A, B

So it creates a contrast. It does not simply negate for no reason; it negates one choice in order to shift attention to another.

That is exactly what is happening here:

• not deciding on your own
• but following the voice guidance

They are similar, but the nuance is a little different.

自分で決めるのではなく、音声案内に従う

This strongly sets up a contrast:

• rather than deciding for yourself, follow the guidance

自分で決めずに、音声案内に従う

This is more like:

• without deciding for yourself, follow the guidance

The first version emphasizes A vs. B more clearly.
The second version focuses more on not doing A while doing B.

In many contexts, both could work, but のではなく is especially good when the speaker wants to clearly correct or contrast two possible approaches.

A few natural translations are:

• Rather than deciding for yourself, follow the voice guidance.
• Don’t decide on your own; follow the audio guidance.
• Instead of making your own decision, follow the spoken instructions.

Even if the exact meaning is already given, this is a good sentence to remember as a grammar model:

• A のではなく、B
• rather than A, B

That pattern shows up very often in Japanese.