Yes, you could still have food in your lungs after 30 days that might or might not be the cause of your “weird-sounding, deep voice”. Food, especially nuts, can linger for a long time and result in irritation or even infection. In addition even after food is coughed-up or removed by bronchoscopy in-hospital, cough and wheeze may persist for months, secondary to foreign-body-induced chemical irritation.
Substances can continue to be released, from the aspirated food, indefinitely. Actually such irritants have probably been the cause of the episodes when your voice quality has changed (“about 5 times”)
Also, more than ½ the time, many foods may not be visible on a routine X-ray.
Pain/tingling of the upper abdomen or bottom right rib cage is a bit worrisome. It raises the question of possible pneumonia with pleurisy caused by the granola.
I strongly suggest that you see your doctor and have a Chest X-ray. The food may not be visible on a plain X-ray but one of your lungs, most likely the right lung may be overinflated. The radiologist would pick this up, especially if the X-ray request states that you have swallowed a foreign body. Please do not delay seeing your doctor.
It may be necessary to have a lung specialist examine your lungs via a fiberoptic bronchoscope and physically remove the offending food.
Good luck
Thanks for the advise, I went to the doctor and had x-rays, Im' OK.