When you have an upper respiratory infection, such as the common cold or sinusitis, your voice may sound nasally due to inflammation and congestion in the nasal passages and sinuses. Here's how it happens:
Nasal Congestion: During an upper respiratory infection, the mucous membranes in your nose and sinuses become swollen and produce excess mucus. This congestion can block the nasal passages and make it difficult for air to pass through freely.
Resonance Alteration: The nasal passages and sinuses are an important part of the vocal resonance system. When you speak, sound waves produced by your vocal cords resonate in your throat, mouth, and nasal cavities before being projected out of your mouth. Normally, only a small amount of sound should resonate in the nasal passages. However, when these passages are congested, more of the sound waves are redirected into the nasal cavity, causing your voice to sound more nasal.
Articulation Changes: Nasal congestion can also affect the way you articulate certain sounds. Some sounds, like "m," "n," and "ng," are naturally nasal sounds, but when your nasal passages are congested, these sounds can become even more pronounced, contributing to the nasally quality of your voice.
Eustachian Tube Dysfunction: Infections can also affect the Eustachian tubes, which are small tubes that connect the middle ear to the back of the throat. Dysfunction of these tubes can cause the ears to feel blocked and may further contribute to changes in voice resonance.
It's important to note that not all upper respiratory infections will cause a nasally voice, and the severity of the nasal quality can vary depending on the extent of the congestion and inflammation.
Usually, the nasally voice resolves as the infection and congestion subside. Over-the-counter decongestants, saline nasal sprays, and staying well-hydrated can help alleviate nasal congestion and may improve the nasally quality of your voice. If the symptoms persist or worsen, or if you have concerns about your respiratory health, it's best to consult a healthcare professional for proper evaluation and treatment.