why should i get a vocal cord injection? 

Vocal cord injections are critical to restore your voice function.

During many neck surgeries, including thyroidectomy and spine procedures, the nerves that move the vocal cords may be injured. These nerves may be completely transected (cut) or simply bruised. The severity of the voice problem is usually related to the severity of nerve injury, with a cut nerve producing the worst voice. However it is not uncommon for simple bruising to result in total loss of nerve function.

Patients who have a vocal cord paralysis after a thyroidectomy or other surgery are often told to wait for their vocal cord (and voice) to recover.

However this recovery may take up to (or more than) a year.

During this time, the patient suffers from a severely breathy voice. This is not acceptable to most patients who are anticipating a 1-2 week recovery from their original surgery. In order to return to work and their social lives, patients need their voice and a vocal cord injection will restore it.

my doctor told me my voice would recover and that i should wait.
is this true? 

If your doctor is telling you your voice will recover, chances are good that it will. However, until it does, you will continue to have voice symptoms, including breathy voice, difficulty with projection, voice fatigue, and throat pain. A vocal injection can minimize or eliminate these symptoms while you are waiting for your voice to recover.

i went to another ent who told me to wait for a year
before i have a procedure. why did they say this? 

It is common teaching to wait one year because nerves may recover during this year. Less experienced surgeons prefer to wait the year rather than risk a complication from a vocal injection. However, this year is very difficult for patients, as they are vocally crippled. A vocal injection is an excellent temporary means of alleviating symptoms while determining if your voice will recover.

will a vocal injection make me less likely to recover my voice?  

No, a vocal injection does not affect your nerve recovery at all. The injection is done into the vocal cord. The recovery is occurring in your nerve, which is not affected by the procedure. Your nerve will continue to heal while you enjoy the benefits of the injection.