1. fivegear's Avatar
    I was wondering if any of you guys could tell me if this phone has full duplex voice calls in the earpiece. I have a Photon currently and really love this ability. It really brings the conversation to life. Thanks for any info!
    11-08-2011 10:25 PM
  2. IAmSixNine's Avatar
    Full duplex calls in the earpiece? The earpiece only produces audio from the person on the other end of the call. Just like your microphone only picks up audio and transmits it to them. The two combined produce full duplex calls. The only way it could be simplex or half duplex would be to have an app like HeyTell where you press a button to send a message. Then wait for a reply.
    But a general phone call will provide full duplex. But maybe i am not understanding the question.
    11-09-2011 09:26 AM
  3. eric3316's Avatar
    Usually this is discussed with speakerphones......I would assume the speakerphones today are full duplex. I know they used to be half and if someone was talking, they would not hear you speak until they stopped talking. If it was noisy on their end you would not even be able to use the speakerphone.
    11-09-2011 09:35 AM
  4. ZDriver's Avatar
    I think he's talking about tone back maybe?? I've heard it discussed before... OP google tone back and see if thats what you're talking about.
    11-09-2011 09:41 AM
  5. fivegear's Avatar
    With the Photon and other Motorola products I have owned in the past, if you talk into the mic during a call you can hear your end of the conversation in the earpiece, just like with a land line phone. It adds to the conversation incredibly and I really like it, it by no means is a deal breaker. I just don't understand why it isn't a standard feature. I can hear what the mic is picking up and move out of the wind or away from a loud noise source if I hear it in the earpiece.
    11-09-2011 11:10 AM
  6. JayWill's Avatar
    Ahhh I see what you're saying. No this phone doesn't do full duplex on the earpiece. In fact, I'd be surprised if the speakerphone is full duplex. You may be able to accomplish it with a bluetooth or plug-in earpiece though.
    11-09-2011 11:18 AM
  7. fivegear's Avatar
    Yeah, full duplex isn't the correct terminology but I didn't know what was. If you Google tone back you get a humorous bunch of different results but none of which were what I was looking for.
    11-09-2011 11:25 AM
  8. dhduvall's Avatar
    I think the right term is "sidetone".
    fivegear likes this.
    11-09-2011 11:30 AM
  9. fivegear's Avatar
    11-09-2011 01:19 PM
  10. rlanza1054's Avatar
    Full Duplex is the correct terminology! (there is a separate channel for the send and receive and they are on all the time). I will look up 'sidetone' but years ago it was labeled as 'Full Duplex'

    Its what your old landline was able to do.

    Motorola was the only cellphone company that produced cellphones with this capability, the old Startek was done with Full Duplex.

    It seems I am the only one that fully understands what user (fivegear) is asking.

    Most cellphones are not produced using Full Duplex because it is a drain on the battery.

    Every manufactured figured we humans can't tell the difference in sound quality and it was an easy way to save the battery.

    Man, I can't tell you how good phone calls sound using Full Duplex in the audio.

    What it is, instead of turning on the microphone when you are talking and then turning it off when your listening for the reply, full duplex keeps both mics on all the time, so you don't get that choppy sound or someone saying to you, please repeat what you just said, I didn't hear the last word you said.

    A perfect example is of a system NOT using Full Duplex is a typical 'Speakerphone', or your cordless phone at home.

    Oh, I just realized that 'fivegear' has a Proton which is a Motorola phone, so I guess they are still using it in their hardware. I guess this is why most people say the sound quality of Motorola phones are very good.

    But in my case, I decided to give up on the voice quality because of 'size' of Samsung Galaxy S II Epic 4G, and how good it is. I don't really talk on the phone that much these days. (Mostly text'ng).

    11-09-2011 09:36 PM
  11. rlanza1054's Avatar
    Just google 'full duplex' and got this from Wikipedia!


    A simple illustration of a full-duplex communication system. Full-duplex is not common in handheld radios like shown here due to the cost and complexity of common duplexing methods.

    A full-duplex (FDX), or sometimes double-duplex system, allows communication in both directions, and, unlike half-duplex, allows this to happen simultaneously. Land-line telephone networks are full-duplex, since they allow both callers to speak and be heard at the same time. A good analogy for a full-duplex system would be a two-lane road with one lane for each direction.
    Examples: Telephone, Mobile Phone, etc.
    Two-way radios can be, for instance, designed as full-duplex systems, which transmit on one frequency and receive on a different frequency. This is also called frequency-division duplex. Frequency-division duplex systems can be extended to farther distances using pairs of simple repeater stations, because the communications transmitted on any one frequency always travel in the same direction.
    Full-duplex Ethernet connections work by making simultaneous use of two physical pairs of twisted cable (which are inside the jacket), wherein one pair is used for receiving packets and one pair is used for sending packets (two pairs per direction for some types of Ethernet), to a directly connected device. This effectively makes the cable itself a collision-free environment and doubles the maximum data capacity that can be supported by the connection.
    There are several benefits to using full-duplex over half-duplex. First, time is not wasted, since no frames need to be retransmitted, as there are no collisions. Second, the full data capacity is available in both directions because the send and receive functions are separated. Third, stations (or nodes) do not have to wait until others complete their transmission, since there is only one transmitter for each twisted pair.
    Historically, some computer-based systems of the 1960s and 1970s required full-duplex facilities even for half-duplex operation, because their poll-and-response schemes could not tolerate the slight delays in reversing the direction of transmission in a half-duplex line.

    11-09-2011 09:37 PM
  12. rlanza1054's Avatar
    Just google sidetone!

    And this is a totally different thing than what the user was asking about.

    Sidetone is using so that you hear your voice as your speak so you have the ability (by way of feedback from your own voice) to control the volume of your own voice.

    I do remember so cellphone phones that did not provide even that (along with not providing Full Duplexing with the caller at the other end), mostly done to make the phone cheaper. I always hated that, because you never knew how to control your voice.

    Here is the explanation from Wikipedia:


    In telephony, sidetone is the effect of sound that is picked up by the telephone's mouthpiece and in real-time introduced at a low level into the earpiece of the same handset, acting as controlled feedback. Sidetone in 19th century telephones varied until the carbon transmitter was used, which produced a distinct sidetone that discouraged speaking loudly enough, and occasionally so loud as to throw the instrument into uncontrolled oscillation or "howling". Sidetone is inactive when phones of any kind are running in speakerphone mode, due to perpetual and almost immediate feedback looping. Anti-sidetone circuitry incorporating the principle of the hybrid coil brought sidetone under control in the early 20th century, leaving enough to assure the user that the phone is really working, and allowing the use of a unitized telephone handset. In cellular technologies, one of the many benefits of sidetone-enabled phones is that a user knows a call has been dropped or ended if he or she no longer hears sidetone.
    Usability studies done at RIM (manufacturers of BlackBerry smartphones), LG and Motorola have demonstrated that a lack of sidetone has a tendency to make the user of a phone or cellular handset characterize it as dead or disconnected. In the same battery of tests, it was found that the presence of sidetone prevents users from needing to examine the device's display to determine if a call is still active. First introduced in the StarTAC handset, almost all cellular handsets manufactured by Motorola have sidetone, though its level of feedback ajustable by the user. Too much sidetone causes users to hear their own voice loudly which is why it is not standard on all cellular handsets and leaves the decision to incorporate sidetone up to the manufacturers. In usability studies prior to the launch of Apple's first-generation iPhone, users were quoted as feeling uncomfortable when the amount of sidetone is too high and will lower the level of their voice unnecessarily. Currently, the iPhone does not have +6% - +9% sidetone,[clarification needed] while almost all Android, Palm, and Windows mobile devices do.
    Digital telephones lack the mechanical acoustics and circuitry that used physical wiring to produce sidetone in older landline phones, so digital phones include electronic circuitry, software and firmware to reproduce sidetone. Many cell phones do not provide adequate sidetone despite general agreement among leading industrial design & usability experts who claim it is an important feature in cell phones, perhaps even more so than for land-lines because of the less predictable acoustics one will encounter while using a cellular phone.
    Almost all land-line (wired and wireless) phones have employed sidetone, so naturally it was an expected convention for cellular telephony but is not standard by any means. Usability experts believe that lack of adequate sidetone causes some people to shout or speak too loudly when using a cell phone (this behavior is often referred to as "cell yell").[1][2]
    Sidetone is valuable for the hearing impaired. The amount of sidetone typically found on land-lines is 8%, and is 4% for cellular phones. Sidetone can be, and often is, amplified for land-line phones for the hearing impaired. In VOIP technologies such as Skype, sidetone has been experimented with but has not been formally adopted by software or hardware & accessories creators. Several software packages and wiring workarounds have been developed that replicate sidetone, but feedback looping remains a problem.

    11-09-2011 09:43 PM
  13. fivegear's Avatar
    Now if there were just an easy way to enable it on other phones! Yes I have a Motorola Photon, and yes it allows for sidetone. I also have a Blackberry and it too has sidetone, I think it is very sad that manufacturers fail to include this feature so often.
    11-09-2011 10:14 PM
  14. IAmSixNine's Avatar
    Sorry. My years of working on 2-way radio equipment kicked in when the full duplex question was asked. I didnt realize there were small amounts of audio feedback coming from the microphone to give sidetone. Great bit of info. Now i want to test my EVO 3D vs my Epic Touch and see if or how noticeable it is.
    11-10-2011 09:54 AM
  15. CAL7's Avatar
    I realize I'm resurrecting an old thread, but searching around, this is the only intelligent conversation about sidetone and full-duplex I could find. Hope someone's still listening.

    I'm still confused. Most reports say cell phones are full-duplex, but the bane of my existence is the Roger, Over nature of my phone calls. Telcos figured this out 50 years ago! From reading this thread, maybe it's sidetone that I really need? Cell phones are supposed to be full-duplex, yet it sure doesn't seem this way.

    Bottom line: What's it take to have a real simultaneous conversation? Do Motorola handsets solve the problem? If so, the other party probably doesn't have a Moto handset, so I'm still not solving the problem. Does the carrier make a difference? Hope somebody smarter than me can tell me how to get calk quality like I had 30 years ago on POTS.
    10-11-2013 08:57 AM
  16. IAmSixNine's Avatar
    Yes all cell phones are Full Duplex. You can transmit voice and receive voice at the same time.
    But as a couple of people have pointed out sidetone is not on all devices.
    With many calls being handled from cell to cell its hard to get things 100% correct.
    The best way to test out stuff is with cell to land line. This way your only dealing with any communication errors (assuming the land line is working properly) on the cellular side of 1 conversation and not 2.
    I repair handsets for a living (as well as buy and sell) and i have a land line in my office strictly for this purpose. To test out microphones and earpieces and overall cellular connectivity.
    10-11-2013 09:57 AM
  17. CAL7's Avatar
    Thank you. Do you find that using or not using a Bluetooth headset affects the quality of full-duplex?

    Sent from my Kindle Fire HD using Tapatalk
    02-21-2014 08:36 PM
  18. CAL7's Avatar
    I've upgraded from two N1's (for historical reference to the youngsters, that's a 2010 phone) to a N5 and Sony Z1 Compact. Between these two phones on T-Mobile I new get HD and, for the first time EVER, full duplex. I can actually talk and listen at the same time! It's wonderful! I feel like it's 1975 again, when phones worked.
    fivegear likes this.
    03-03-2014 04:18 PM
  19. Mongo X's Avatar
    Not correct - The Samsung Blackjack II's speakerphone was full-duplex also. I searched far and wide for this feature when I bought mine, had it now since new and use everyday.
    "Motorola was the only cellphone company that produced cellphones with this capability, the old Startek was done with Full Duplex."
    02-29-2016 03:59 PM
  20. N Romanski's Avatar
    I was wondering if any of you guys could tell me if this phone has full duplex voice calls in the earpiece. I have a Photon currently and really love this ability. It really brings the conversation to life. Thanks for any info!
    Android phones will full duplex (record their own playback) only with phone calls. Any other full duplexing is prohibited because of specific hardware licencing issues. You can trick it with different hardware interfaces though. I'm not saying anything about that except that it is a wise thing to have saved your old computers from the 90s because they are pre digital rights management and don't have the restrictions that new hardware does.
    10-14-2016 04:09 PM