Return-Path: MIME-Version: 1.0 Content-Type: text/plain; charset="GB2312" Subject: RE: [Bluez-users] Periodic noise on microphone with bt_sco (BTA-6030 Dongle, Motorola H500 Headset) Message-ID: From: "Li, Lea" To: Sender: bluez-users-admin@lists.sourceforge.net Errors-To: bluez-users-admin@lists.sourceforge.net Reply-To: bluez-users@lists.sourceforge.net List-Unsubscribe: , List-Id: BlueZ users List-Post: List-Help: List-Subscribe: , List-Archive: Date: Tue, 8 Nov 2005 09:26:07 +0800 Also, since it is hard to address where the root cause is, maybe you = could divide the test into several steps to find it. Dump the audio = stream into a .pcm/.wav file, and then play the file to check where the = noise comes from - during the transferring process or during the playing = process.=20 Thanks,=20 Lea -----Original Message----- From: bluez-users-admin@lists.sourceforge.net = [mailto:bluez-users-admin@lists.sourceforge.net] On Behalf Of Dirk = Stockmann Sent: 2005=C4=EA11=D4=C27=C8=D5 22:11 To: bluez-users@lists.sourceforge.net Subject: Re: [Bluez-users] Periodic noise on microphone with bt_sco = (BTA-6030 Dongle, Motorola H500 Headset) -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, Steven Singer wrote: > I agree with this diagnostic. If the headset doesn't generate noise > when attached to another device then the noise is probably not being > inserted at the headset end. No noise with two different mobile phones, but with two different = dongles. > One way to confirm whether it's electrical is to record digital signal > received from the dongle into a file, shut down the SCO link and then > play the file to the PC's loudspeakers. When I record "silence" from the microphone (as silent as possible) then there is clearly the noise with about -40db power. Is there a way to record the digital from the headset directly, before it is processed in alsa? Similar to the way hcidump works, maybe? > Are you sending a signal to the headset and, if so, are you hearing a > buzz in the headset's speaker? I'm wondering if a buzz in that > direction (coming from the sensitive microphone input on the PC) is > being looped through the air (or through the plastic) from the > headset's speaker to its microphone. Sound sent to the headset from the PC (e.g. an audiobook) is without the buzz. It is quite low quality (like on a phone) but clear. Regards, Dirk - -- Key can be found on: http://sks.keyserver.penguin.de hkp://sks.keyserver.penguin.de -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFDb2CMLi2VR2b1/voRAsm4AJwJh4tySPRkrzk0V88aGjDqGyzZIgCfd2g8 Q9zUy5UtvCTbifPGH9nSyzg=3D =3Dry8L -----END PGP SIGNATURE----- ------------------------------------------------------- SF.Net email is sponsored by: Tame your development challenges with Apache's Geronimo App Server. = Download it for free - -and be entered to win a 42" plasma tv or your very own Sony(tm)PSP. Click here to play: http://sourceforge.net/geronimo.php _______________________________________________ Bluez-users mailing list Bluez-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bluez-users ------------------------------------------------------- SF.Net email is sponsored by: Tame your development challenges with Apache's Geronimo App Server. Download it for free - -and be entered to win a 42" plasma tv or your very own Sony(tm)PSP. Click here to play: http://sourceforge.net/geronimo.php _______________________________________________ Bluez-users mailing list Bluez-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bluez-users