This isn't the experience you should be having with your fairly new iPhone 4! I would love the opportunity to try and resolve this for you.
When did this problem begin? To clarify, is this happening while using the speakerphone feature only or is the earpiece speaker not working as well? Does the phone sound the audio ringer? If not, ensure the phone is not set to Silent Mode http://vz.to/11DDzyR. Also check to make sure the "Do Not Disturb" http://vz.to/142uG4a setting is "Off". I would also like for you to Soft Reset the device http://vz.to/11jpo29. Let me know how these troubleshooting steps work out for you. Thanks!
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